screening test research paper

FDA approves self-tests for cervical cancer, as an alternative to the dreaded pelvic exam

The U.S. Food and Drug Administration late Tuesday approved a new way for people to screen for signs of cervical cancer.

Patients using the new method will self-screen with a swab at the doctors office to test for the HPV virus, bypassing the need for doctors to perform invasive, often uncomfortable, pelvic exams.

"It's to reach women who traditionally haven't been reached," said Jeff Andrews, vice president of medical and scientific affairs at BD, one of the makers of the new method.

While the first tests are expected to be reserved for clinic use, BD plans to eventually offer an at-home option, Andrews said. Roche, another provider whose product was approved, also plans to consider an at-home option.

The new tests could be conducted in a doctor's office, a mobile clinic or a retail pharmacy, with the sample then sent to a lab. The clinician would follow up with results and next steps, Andrews said.

Both are expected to be available this summer.

Such expanded screening options, Andrews said, eventually "could eliminate cervical cancer in the U.S."

How it works

A medical provider would give the self-collection swab to the patient to take into the bathroom, similar to the routine of an in-office urine test.

The patient would then insert the cotton-swab-like test into the vagina and swirl it around three times. They would deliver the completed test back to the provider, to send to a lab for evaluation.

Patients hear results from their clinician, who may advise further testing if the results are abnormal. Additional testing could mean a clinician orders another self-collection, or if the lab detects potentially dangerous forms of HPV, a full pelvic exam and further testing may be conducted.

Both BD's Onclarity test and Roche's cobas test report on 14 strains of HPV.

Eliminating the risk of cervical cancer

Cervical cancer can be prevented and cured if caught early enough.

But the disease remains the fourth most common form of cancer among women globally, according to the World Health Organization . The WHO hopes to screening can be expanded worldwide by 2030, so that 70% of women are screened by the age of 35, and again by the age of 45.

In the U.S., most of the 13,000 new cases of cervical cancer diagnosed each year are among people who weren't screened in the previous five years, according to the U.S. Centers for Disease Control and Prevention. This presents an opportunity for new developments in screening, according to Andrews, especially among people at higher risk because they cannot regularly access gynecologic care.

"This cancer is unique," Andrews said. "The goal with other cancers is early detection and treatment. The goal with cervical cancer is to find pre-cancerous cells, treat them and never have cancer."

Treatment options depend on what type of precancerous cells are detected, the extent of severity and a person's medical situation, he said.

An alternative option to a pelvic exam

Most primary care doctors don't perform pelvic exams, meaning patients traditionally have to go to a gynecologist-obstetrician (OB-GYN) if they want to screen for cervical cancer.

With the self-collection option, more patients can screen for disease without having to book an additional appointment that costs time and money.

The cost of a self-screen will be the same as the pelvic exam, Andrews said, because the sample is sent to a lab, which charges for their pathology. Screening for cervical cancer is required to be covered by the Affordable Care Act, commonly called Obamacare, for those with insurance.

The arrival of a self-screening option doesn't replace the need for an annual OB/GYN visit which involves other aspects of reproductive health care. But it does mean that OB/GYN appointment could come with reduced anxiety about a pelvic exam.

"This is not to replace the role of an OB/GYN in your care," said Dr. Anne-Marie Amies Oelschlager, an OB/GYN professor at the University of Washington and chair of the clinical consensus gynecology committee at the American College of Gynecologists and Obstetrics (ACOG). "It doesn't take the place of being able to talk about contraception, to talk about whether you're in a safe relationship, to talk about your periods ... it doesn't take the place of breast cancer screening."

There are a lot of reasons why someone may want to avoid a pelvic exam at the OB/GYN if it's not medically necessary, Oelschlager said. People may have stress from a prior negative pelvic exam experience, feel pain in that area if they have a condition or be re-traumatized if they have a history of sexual abuse.

"Self-screening would be one way for them to have more control over what happens to them in that part of the exam," Oelschlager said.

She and other experts with ACOG have said patients should be involved in the decision whether to have a pelvic exam. For those without symptoms, such as a prior abnormal HPV test, vaginal discharge or pain in intercourse, pelvic exams may not necessary, Oelschlager said. "It's a way of figuring out who needs additional testing and who can safely wait before repeat testing."

Does this have anything to do with HPV vaccine?

The CDC first recommended vaccinating against the most common strains of human papillomavirus, the sexually transmitted virus that causes cervical cancer in 2006. Today, the CDC recommends all children receive the vaccine starting around age 11.

The vaccine was initially targeted at girls only, but has expanded to include everyone. Vaccinated boys can't pass HPV to partners with vaginas. Vaccination also protects against genital warts as well as throat and penile cancer , said Lonna Gordon, a doctor of adolescent medicine at Nemours Children's Hospital in Orlando, Florida.

And adults who didn't get the shot when they were younger can still get vaccinated, Oelschlager said.

Anyone who is vaccinated but has an unvaccinated partner is protected from the disease but should also keep up with regular cervical cancer screening: "The vaccine does not eliminate the need for a screening test," Gordon said.

A matter of inclusion

Cervical cancer screening is most often missed by people in rural areas and members of the LGBTQ community, Oelschlager said.

Because gynecological care is highly gendered, there are barriers to accessing this kind of care for people who don't identify as women, said Stephen Martin, assistant professor of gynecology and obstetrics at the Johns Hopkins University School of Medicine. These more translatable screening options have a high potential to diversify gynecology care, he said.

"The barriers begin with just walking in the door," Martin said, "In most gynecologists' offices, you're going to be potentially surrounded by [cisgender] women and pregnant women." In many places, the staff are not trained to provide gender-diverse care, Martin said, and gender identity can exacerbate the stress and emotion involved in receiving a pelvic exam.

Offering options like self-screening can build trust between providers and patients from marginalized communities, Martin said. "That way, even if an exam does need to be done, it's done with the patient, not on the patient."

FDA approves self-collection screening for virus that causes cervical cancer

Women’s health advocates view the move as crucial to stamping out the preventable disease.

The Food and Drug Administration this week moved to expand screening for potentially lethal cervical cancer by allowing women to collect test samples themselves, a move that reproductive health advocates view as crucial to stamping out the preventable disease.

For the first time, women will be able to gather samples for testing in private rooms inside offices of primary-care doctors, at urgent-care clinics and even pharmacies — an advance that could presage home testing.

Advocates hope the method will make it easier for women of color and those living in rural and underserved communities to screen for human papillomavirus — HPV — which can lead to a cancer that afflicts 11,000 each year. It comes as the National Cancer Institute has ramped up study of self-collection, partnering with 25 medical schools and cancer centers across the country to gauge use of collecting vaginal samples at home and at health-care facilities.

“It provides women who might not have otherwise had the opportunity — or inclination — to get screened the chance do so,” said Erin Kobetz, associate director for community outreach and engagement at the University of Miami Sylvester Comprehensive Cancer Center, who has studied self-collection for HPV testing for nearly two decades. “Maybe it makes this idea, at least in the United States, of eliminating cervical cancer by 2030 a perceptible reality.”

The collection method was greenlit for the previously approved HPV test Onclarity, manufactured by BD (Becton, Dickinson and Company). The test is expected to be available in summer and will be part of a study of self-collection, the company said in a news release Wednesday.

Roche also received sign off for the self-collection method for its cobas HPV Test, and has been collaborating with the NCI’s study, the company said in a news release.

Meanwhile, the FDA could sign off on at-home collection in coming months. Teal Health created a device that lets women collect their own vaginal samples and send them to a laboratory for testing. Last week , the test received a special designation from the FDA that allows agency staffers to review certain devices faster.

Most primary-care physicians do not test for HPV. Typically, it’s performed by gynecologists, who collect samples for an HPV test or for a Pap smear for abnormal cervical cells. Often, the samples are taken during a pelvic exam.

The new method “opens the door to a less invasive testing option,” the company said. It will still require an order from a doctor, who will be required to explain the results. But the samples can be collected by a woman using a vaginal swab in a health-care facility “like you would a urine sample,” said Jeff Andrews, vice president of medical affairs for BD. The swab is then sent to a lab equipped to test the sample.

Andrews added the test is already covered by private insurance, Medicare and Medicaid, which typically pays clinical, hospital and other labs about $46 per screening. BD sells the tests to labs.

Self-collection won’t replace testing for HPV during routine pelvic exams, but it will add another way to improve earlier detection of the infection.

“This literally just opens up another option for a different demographic of people that might not feel comfortable, that might not have access [and] may not have time” to get tested otherwise, said Irene O. Aninye, chief science officer for the Society for Women’s Health Research, a group focused on advancing women’s health and promoting research.

The method has already proved successful in European countries and Australia.

Now, federal researchers are beginning to gather data on whether self-collection works well in the United States. NCI in January launched its initiative to study self-collection, aiming to answer critical questions.

“The study will provide us the data to know what’s the uptake like, what do people do with this information? How is it received in different clinical settings, and do people engage with their gynecologists in a different way? And then ultimately, do we see a difference in cervical cancer cases?” NCI director Kimryn Rathmell said.

In the United States, the FDA’s approval of the BD test is the culmination of decades of research. Kobetz began studying self-collection in Miami’s Little Haiti neighborhood, where women of Haitian heritage shied away from Pap smears for complex reasons, including the perception the tests were intrusive and concerns about intimacy and vulnerability, Kobetz said.

Her study found self-collection was accurate — women who participated in the study obtained enough cells to test for HPV and they “really found this to be an appropriate method for cervical cancer screening — and an easy one,” Kobetz said.

The goal is for at-home tests to become easily available, said William L. Dahut, chief scientific officer at the American Cancer Society. Doing so, he believes, would increase the number of people who get screened for HPV.

In 2006, the FDA approved the first vaccine to prevent HPV, but uptake varies widely by state. The shots have the potential to prevent more than 90 percent of HPV-attributable cancers, according to the Centers for Disease Control and Prevention. While vaccination significantly reduces the chance of infection, it doesn’t eliminate risk of cervical cancer, so it remains important for people to get screened, Dahut said.

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Multi-Target Stool DNA Test for CRC Screening: How Accurate is the New Version?

Philip schoenfeld, md, msed, msc (epi),   chief (emeritus), gastroenterology section, john d. dingell va    medical center, detroit, mi..

This summary reviews Imperiale T, Porter K, Zella J, et al. Next-generation multitarget stool DNA test for colorectal cancer screening. N Engl J Med 2024; 390: 984-93.

Access the article through PubMed

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Correspondence to Philip Schoenfeld, MD, MSEd, MSc. Editor-in-Chief. Email: [email protected]

Keywords: colorectal cancer screening, stool test, fecal immunochemical test

STRUCTURED ABSTRACT

Question: What is the sensitivity and specificity of a new version of a multi-target stool DNA test (mt-sDNA) for colorectal cancer (CRC) screening for detection of stage I, II, and III CRC and advanced precancerous lesions in average-risk individuals aged > 40 years old?

Design : The BLUE-C study is a prospective, observational diagnostic test study using colonoscopy as the gold standard for detection of CRC and precancerous lesions.

Setting:  One-hundred eighty-six sites in the United States.

Patients: Asymptomatic individuals > 40 years old scheduled for CRC screening colonoscopy. Key exclusion criteria included: (a) history of inflammatory bowel disease; (b) prior history of advanced adenomatous polyps or CRC; (c) medical or family history of inherited polyposis syndromes; and (d) currently up to date with CRC screening (e.g., had a normal screening colonoscopy < 9 years or negative fecal immunochemical test (FIT) within previous 6 months). Individuals with family history of CRC in first-degree relatives were also included.

Interventions/Exposure : Stool specimens for next-generation mt-sDNA test and FIT were obtained prior to colonoscopy bowel preparation and mailed for processing.  The next-generation mt-sDNA test analyzes DNA abnormalities in colonic mucosal cells sloughed from the colon wall into stool. The new molecular panel encompasses additional methylated DNA markers compared to the current version of mt-sDNA test while continuing to test for fecal hemoglobin. Separate FIT was considered positive based on threshold of 100ng/ml of hemoglobin.

Outcome: Primary outcome was sensitivity for CRC and specificity for advanced neoplasia, defined as CRC plus advanced precancerous lesions, which were defined as adenomas > 10mm, adenoma with villous histology or high grade dysplasia, carcinoma in situ, or serrated lesion > 10mm. Secondary outcome was sensitivity for advanced precancerous lesions and comparison of sensitivity of FIT and next-generation mt-sDNA test for CRC and advanced precancerous lesions.

Data Analysis : Sensitivity (percentage of individuals with the disease who have a positive test) and specificity (percentage of individuals without the disease who have a negative test) with corresponding 95% confidence intervals (CIs) were calculated with standard formulas. For previous FDA-approved CRC screening tests, a test was considered acceptable if the lower boundary of the 95% CI for CRC sensitivity was >65% and if the lower boundary of 95% CI for specificity of advanced precancerous lesions was >85%.

Funding:  Exact Sciences, manufacturer of Cologuard and next generation Cologuard/Cologuard 2.0.

Results:  Between November 2019 and January 2023, 20,176 individuals had full data from colonoscopy and stool tests completed. Overall, mean age was 63 years old, 53% were female, 60% were White, 5.2% with family history of CRC in a first-degree relative, and 13.4% had positive next-generation mt-sDNA test. Among the individuals with full data, 0.5% (98/20,176) had CRC and 10.6% (2,144/20,176) had advanced precancerous lesions. Among individuals with CRC, 84% (82/98) had stage I-III CRC.

For CRC stages I-III, 92.7% (76/82) had a positive next generation mt-sDNA test. Per the study, sensitivity did not vary substantially based on disease stage or location in the colon. For advanced precancerous lesions (large adenomas, large sessile serrated polyps, villous adenomas or adenomas with high-grade dysplasia or carcinoma in situ), 43.4% (931/2,144) had a positive next generation mt-sDNA test and sensitivity rose to 74.6% when limited to lesions with high-grade dysplasia (85/114) ( Table 1 ).  Approximately 7% of participants had a false positive test, defined as positive stool DNA test but no adenomas, advanced precancerous lesions, or CRC found on colonoscopy.

Since FIT had only 64.6% sensitivity for stages I-III CRC and 23.3% sensitivity for advanced precancerous lesions (Table 1), the mt-sDNA test was significantly better for both comparisons. The stool DNA test was positive for 79% (23/29) of stage I-III CRC where FIT was negative, and stool DNA was positive for 34% (555/1644) of advanced precancerous lesions where FIT was negative. However, only 4.3% of participants had a false positive FIT, which was defined as positive FIT but no adenomas, advanced precancerous lesions, or CRC found on colonoscopy.

Table 1. Sensitivity of next generation multi-target stool DNA test and fecal immunochemical test.

Why Is This Important? As discussed in prior commentaries, 1 only about 59% of the eligible US population is up to date with CRC screening, equating to more than 40 million unscreened individuals. Therefore, new interventions to improve screening are sorely needed. 2 Given the desire of some patients to avoid colonoscopy with the associated bowel preparation, sedation, and time missed from work, stool-based tests for CRC screening are a viable option. Although annual FIT is inexpensive for healthcare systems, the sensitivity for Stage I-III CRC is 65% (i.e., approximately 35% of individuals with Stage I-III CRC will have a negative test). The limited sensitivity of FIT could be overcome by performing it annually, but multiple studies demonstrate that adherence to FIT is at best 75% and then decreases to approximately 30%-35% in subsequent years. 2-4 Therefore, stool-based tools with improved sensitivity and higher adherence would be beneficial.In the study by Imperiale et al, the next generation mt-sDNA  test demonstrates superiority to FIT for sensitivity of stage I-III CRC (92.7% vs 64.6%) as well as for advanced precancerous lesions (43.4% vs 23.3%) while improving specificity to 92.7% for non-neoplastic or negative colonoscopy. Compared to the currently available mt-sDNA test, 5 the sensitivity remains the same, but the specificity is improved, leading to fewer false-positive tests requiring colonoscopy. Finally, based partly on quality control processes developed by Exact Sciences, adherence to completing mt-sDNA tests may be twice as high compared with standard FIT (85% vs 43%). 6

Key Study Findings

Caution The next-generation mt-sDNA test was not directly compared to the current version, limiting assessment of how the new DNA biomarker panel improves diagnostic test characteristics for stage I-III CRC and advanced precancerous lesions.

My Practice As per prior commentaries, 1 colonoscopy is my primary tool for CRC screening since it’s also a CRC prevention tool. Nevertheless, I do see average-risk individuals who are fearful of colonoscopy, sedation, or simply doing the bowel preparation and want a non-invasive alternative. What’s the best option for these individuals? At my VA institution, we’re limited to offering annual FITs as a stool-based screening test, and this is certainly an appropriate cancer detection tool. However, mt-sDNA tests clearly produce higher sensitivity than FIT for stage I-III CRC and advanced precancerous lesions. This limitation may be overcome if patients get FIT annually, but adherence to annual FIT may be less than 40% in repeated years and adherence to mt-sDNA is considerably better.Of course, mt-sDNA tests are significantly more expensive than FIT as a CRC screening test, but this cost is borne by insurers instead of individual patients, since mt-sDNA tests are covered under the Affordable Care Act as an approved CRC screening test. Therefore, the out-of-pocket cost for a vast majority of CRC screen-eligible individuals will be zero.

For Future Research Future efforts to improve specificity (i.e., minimizing frequency of false positive tests, which drives use of colonoscopy) while preserving high sensitivity for CRC will be beneficial. Since mt-sDNA tests are recommended for use every 3 years, additional longitudinal data will also be helpful.

Conflict of Interest Dr. Schoenfeld previously served as a speaker for Exact Sciences and has discontinued that relationship.

Note: The authors of this study are active on social media. Tag them to discuss their work and this EBGI summary.

@DrJohnKisiel John Kisiel

@limberg_paul Paul Limberg

• Schoenfeld P. Cell-free DNA blood test for CRC screening: a promising development won’t “eclipse” current tools. Evidence-Based GI. Published April 24, 2024. Accessed May 10, 2024. https://gi.org/journals-publications/schoenfeld_April2024/
• Carethers J. Improving noninvasive colorectal cancer screening. N Engl J Med 2024; 390: 1045-46.
• Fisher DA, Princic N, Miller-Wilson LA, et al. Adherence to FIT screening among adulats at average risk for CRC. Int J Colorectal Dis 2022; 37: 719-21.
• van der Vlught M, Grobbee EJ, Bossuyt P, et al. Adherence to CRC screening: four rounds of faecal immunochemical test-based screening. Br J Cancer 2017; 116: 44-49.
• Imperiale TF, Ransohoff DF, Itzkowitz SH, et al. Multitarget stool DNA testing for colorectal-cancer screening. N Engl J Med 2014; 370: 1287-97.
• Finney Rutten LK, Jacobson DJ, Jenkins GD, et al. CRC screening completion: an examination of differences in screening modality. Prev Med Rep 2020; 20: 101202.

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• Published: 13 May 2024

Evaluations of modes of pooling specimens for COVID-19 screened by quantitative PCR and droplet digital PCR

• Daitao Zhang 1 ,
• Lingyu Shen 1 ,
• Zhichao Liang 1 &
• Shujuan Cui 1  

Scientific Reports volume  14 , Article number:  10923 ( 2024 ) Cite this article

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• Microbiology

Though pooling samples for SARS-CoV-2 detection has effectively met the need for rapid diagnostic and screening tests, many factors can influence the sensitivity of a pooled test. In this study, we conducted a simulation experiment to evaluate modes of pooling specimens and aimed at formulating an optimal pooling strategy. We focussed on the type of swab, their solvent adsorption ability, pool size, pooling volume, and different factors affecting the quality of preserving RNA by different virus solutions. Both quantitative PCR and digital PCR were used to evaluate the sampling performance. In addition, we determined the detection limit by sampling which is simulated from the virus of different titers and evaluated the effect of sample-storage conditions by determining the viral load after storage. We found that flocked swabs were better than fibre swabs. The RNA-preserving ability of the non-inactivating virus solution was slightly better than that of the inactivating virus solution. The optimal pooling strategy was a pool size of 10 samples in a total volume of 9 mL. Storing the collected samples at 4 °C or 25 °C for up to 48 h had little effect on the detection sensitivity. Further, we observed that our optimal pooling strategy performed equally well as the single-tube test did. In clinical applications, we recommend adopting this pooling strategy for low-risk populations to improve screening efficiency and shape future strategies for detecting and managing other respiratory pathogens, thus contributing to preparedness for future public health challenges.

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Sample pooling as a strategy for community monitoring for SARS-CoV-2

A four specimen-pooling scheme reliably detects SARS-CoV-2 and influenza viruses using the BioFire FilmArray Respiratory Panel 2.1

Pooling RT-qPCR testing for SARS-CoV-2 in 1000 individuals of healthy and infection-suspected patients

Introduction.

Since January 2020, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide, seriously endangering public health and economic development. Due to the highly infectious nature of SARS-CoV-2, timely diagnosis and isolation of patients are the most effective ways to prevent the spread of the outbreak 1 , 2 , 3 , 4 , 5 . Currently, the primary method used to diagnose coronavirus disease 2019 (COVID-19) is the reverse transcription quantitative PCR (RT-qPCR), which is highly sensitive and specific but costly and relatively time-consuming 6 , 7 , 8 , 9 , 10 . Owing to limited resources, RT-qPCR testing is often limited to suspected patients with apparent symptoms. However, studies have shown that asymptomatic or mildly symptomatic patients can also transmit the virus 11 . Large-scale screening in communities, where patients have been diagnosed, can effectively control the spread of the virus 12 , 13 . However, large-scale screening poses severe challenges to the testing capacity of laboratories, and it is unaffordable for low-income countries with insufficient resources. A pooled test is an effective strategy to cope with this demand.

In practice, the pooled test of SARS-CoV-2 14 mainly includes two methods, media pooling 11 , 15 , 16 , 17 , 18 , 19 , 20 and swab pooling 21 , 22 . Media pooling is combining equal amounts of solution from multiple specimen tubes, while swab pooling is putting multiple swabs into a single tube, and this theoretically does not dilute the concentration of the virus. Lohse et al. 11 and Hogan et al. 18 conducted multiple media pooling tests and observed them as effective means for large-scale screening in addition to saving time and consumables. However, some studies suggest that due to the presence of negative specimens, media pooling reduces the detection sensitivity. Abdalhamid et al. 16 tested 25 experimental media pools, each containing one SARS-CoV-2 positive specimen mixed with four negative specimens (50 μL each) for a total volume of 250 μL. They found that the cycle threshold (Ct) v Clinical evaluation of bacterial lues were higher than the original individual specimens within a range of 0–5.03 Ct. Swab pooling, which increases the number of swabs without increasing the volume of the preservation solution, did not dilute the virus concentration of positive samples. Christoff et al. 22 compared pooled and individual samples from 613 patients and found no false negatives or false positives in the pooled tests. Chen et al. 21 investigated the difference between the detection results of media/swab pooling and the individual test and concluded that media pooling significantly reduces the Ct value and that swab pooling does not affect the detection sensitivity. The U.S. Centers for Disease Control and Prevention pooling amendment gives details of media and swab pooling 23 procedure used in different studies.

There are many confounding factors for swab pooling, such as normalization of the sampling process, viral load of the sample, RNA extraction efficiency 24 , and the sensitivity of the assay type. In this study, we examined the influence of swab numbers, type of sampling swab 25 , type of virus preservation solution, volume of the sampling solution, virus load of the positive cases and storage conditions of specimens on the sensitivity of a pooled test. We evaluated the sensitivity and feasibility of pooling specimens by RT-qPCR 26 , 27 . and droplet digital PCR (RT-ddPCR) 28 to optimize the swab pooling strategy.

Materials and methods

Ethics statement.

This study was reviewed and approved by the Ethics Committee of the Beijing Center for Disease Control and Prevention (2021026). Since these samples were initially sent for SARS-CoV-2 case confirmation and epidemic control, this study only collected control data without written informed consent. In addition, all methods were performed in accordance with the relevant guidelines and regulations by including a statement. Informed consent was obtained from all the participants.

Sample collection and RNA extraction

Throat swabs used in the study was collected from healthy individuals with no respiratory symptoms and others who were unwell. To minimize the differences introduced by the sampling process, samples used in the study was collected by one individual, from one site, following the same collection procedure. The swabs were soaked in a virus preservation solution and immediately vortexed for 15 s. Viral RNA was extracted using KingFisher Flex (Thermo Scientific, Waltham, MA). The amount of each sample used was 200 µL and that of the elution solution was 60 µL. Two titers of Viral RNA standard materials were inactivated at 56 °C for 30 min, and confirmed by RT-qPCR according to the Prevention and Control Scheme of China, giving Ct values of N gene of 24.2 and 29.1.

RT-qPCR and droplet digital PCR protocol

RT-qPCR was performed on the ABI Prism 7500 system (Thermo Scientific, Waltham, MA) by a 20 μL mixture that contained SARS-CoV-2 diagnostic assays (Kinghawk Pharmaceutical, Beijing, China) following the instructions detailed in the kit. Specifically, a 25 μL mixture is prepared, comprising the diagnostic assays along with 5 μL of nucleic acid (procured from the China National Institute of Metrology, model GBW(E)091089). The RT-qPCR kit detected opening reading frame (ORF) 1ab, the nucleocapsid protein (N) gene and RNase P (RNP), an internal reference gene in human epithelial cells, simultaneously. The RT-qPCR program was 50 °C for 30 min, then 95 °C for 3 min, and followed by 40 cycles at 95 °C for 10 s and 55 °C for 30 s. This adjustment is aligned with the kit's instructions and aims to enhance the reproducibility of the RT-ddPCR experiments.

The digital PCR (RT-ddPCR) system was the TD-1 Droplet Digital PCR System (TargetingOne, Beijing, China). RT-ddPCR was carried out with the SARS-CoV-2 nucleic acid detection kit (TargetingOne, Beijing, China) according to the manufacturer’s instructions. The master mix included 1× ddPCR supermix for probes, forward and reverse primers at 400 nmol/L, and GRAM+/GRAM− probes at 200 nmol/L. Each well was filled with a 1-µL sample of DNA and DNase/RNase Free water, resulting in a final volume of 30 µL. Following droplet generation, the samples were amplified with the following thermal cycling program: 55 °C for 15 min, 95 °C for 10 min, 45 cycles of 94 °C for 30 s and 57 °C for 1 min, and finally held at 12 °C for 5 min. The PCR amplification was performed on the A 300 instrument (LongGene, Hangzhou, China) with a 1.5 °C/s ramp. Finally, the thermally cycled samples were loaded onto the chip reader, and the data from cluster plots were analyzed by the analysis software.

Study design

As illustrated in the flowchart in Fig.  1 a, we compared the performance of three brands of fibre swabs (labeled as Fib-1, Fib-2, Fib-3) and three brands of flocked swabs (labeled as Flk-1, Flk-2, Flk-3) in scraping quality, adsorption capacity, and release quality, respectively. We also tested six virus preservation solutions, including both three non-inactivating virus preservation solutions (labeled as NS-1, NS-2, NS-3) and three inactivating virus preservation solutions (labeled as IS-1, IS-2, IS-3) of different brands, to evaluate the effect of the pooled tests. Each experiment group had three replicates.

( a ) Schematic diagram of the parameters tested. There were two types of swabs, fiber and flocked. And the properties tested for swabs were scraping quality, absorption capacity, and release quality. There were two types of preservation solutions, inactivating and non-inactivating. The solutions were tested for the solution quality, glass beads effect and whether the solutions are inactivated. Lastly, the pooling strategy (the number of swabs and the volume of preservations solution), the sensitivity and specificity of the pooled test, the performance of the preservation solution, and the influences of storage conditions were characterized by RT-qPCR and RT-ddPCR. ( b ) Schematic diagram of specimen pooling strategies. In the first stage of swab pooling, multiple swabs are pooled in a single sampling tube. If a positive sample is found, in the second stage of swab pooling, the attributors of swabs in the positive sample tube, need to be re-sampled and re-tested separately in order to find the corresponding positive sample.

As shown in Fig.  1 b, in the first stage, different numbers (the “n” in “X n ”) of swabs were pooled in tubes to determine the optimal pool size and the volume of virus preservation solution to use. The sensitivity and specificity of the pooled test, and the preservation performance of the preservation solutions, were characterized by RT-qPCR and RT-ddPCR.

Data analyses

Statistical analysis was determined by GraphPad Prism (GraphPad Software, San Diego, CA). Significant differences between the two groups were determined by the unpaired Student’s t -test. All reported p-values less than 0.05 was considered statistically significant, where “*” represents p < 0.05, “***” represents p < 0.001 and “ns” represents no significant difference.

Comparison of sampling quality of different types of swabs

To compare the scraping quality of fibre swabs and flocked swabs, we collected throat swabs from healthy people with six brands of swabs, according to the pharyngeal swab sampling specification. The swabs were each placed in a sampling tube with 3 mL PBS. The sampling tube vortexed for 20 s, and then 200 µL was taken for nucleic acid extraction. The extracted nucleic acid was tested in triplicate by RT-qPCR. RNP quantification by RT-qPCR showed that the scraping quality of flocked swabs was better than fibre swabs (Fig.  2 a).

( a ) Detection results of different fibre and flocked swabs in terms of the scraping quality. ( b ) Absorption volume of different fibre and flocked swabs. ( c ) Detection results of different fiber and flocked swabs that were soaked in two titers of viral RNA standard materials.

To compare the adsorption capacity of different swabs, each swab was submerged in 3 mL PBS in a sampling tube for 10 s and then discarded. After centrifuging the sampling tube, we calculated the absorption volume by measuring the remaining volume of PBS. The average adsorption volumes of fibre swabs and flocked swabs were 148 μL and 214 μL, respectively, indicating that flocked swabs have better adsorption capacity (Fig.  2 b).

Studies suggest that release quality of the swabs is closely related to the sensitivity of the test. To compare the release quality of different swabs, we immersed each swab in 100 µL viral standard materials with Ct = 24.2 and Ct = 29.1 and then placed it in 3 mL PBS in a sampling tube. We then vortexed the tube for 20 s, and took 200 µL for RNA extraction. The extracted RNA was quantified in triplicate by RT-qPCR for SARS-CoV-2. As shown in Fig.  2 c, the release quality of the flocked swabs was superior to that of the fibre swabs, especially when the virus load was low.

Comparison of the performance of different types of RNA virus preservation solutions

We selected two variables to determine the effect of the type of RNA virus preservation solution on the preservation of samples. First, whether the kit was inactivated; and second, whether there were glass beads in the virus preservation solution. Twelve identical flocked swabs were divided into two groups and immersed in two concentrations of viral standard materials. The swabs were then removed and placed in six virus preservation solutions: inactivating (IS-1, IS-2, IS-3) and non-inactivating (NS-1, NS-2, NS-3).

The Ct value was used to characterize the RNA preservation performance of the preservation solution. As shown in Fig.  3 a, there was no significant difference between the non-inactivating and inactivating virus preservation solutions when the amount of virus on the sampled swab was high. When the amount of virus on the sampled swab was low, the non-inactivating solution had a slight advantage over the inactivating solution. The glass beads in the solution had no significant effect on the virus release from the swab, as shown in Fig.  3 b.

( a ) Comparison of the preservation effect of inactivating and non-inactivating virus preservation solutions. ( b ) Effect of the presence of on the test results.

Determining the optimal number of swabs for swab pooling

Two brands of commercial SARS-CoV-2 RNA detection kits and two types of virus preservation solution were used to form four sets (labeled as XY-NS, XY-IS, YK-NS, YK-IS). Each set contained nine 50 mL centrifuge tubes with 15 mL of the virus preservation solution, one 10 mL centrifuge tube with 3 mL of the virus preservation solution, and a number of swabs, to determine the optimal number of pooled swabs for pooled test. Every set was used as follows: 10 swabs were completely immersed in the viral standard materials for 10 s and then placed in the 10 centrifuge tubes with virus preservative solution. Healthy individuals were sampled with swabs from the four sampling sets, and those collected swabs were used as negative samples. Different numbers of negative swabs were placed in each of the 10 centrifuge tubes containing one positive swab. The nine 50 mL centrifuge tubes were given 0, 2, 4, 6, 9, 11, 14, 16, and 19 negative swabs; and the one 10 mL centrifuge tube was not given any negative sample. The tubes were vortexed for 20 s, and 200 μL was removed for RNA extraction. The amount of virus was quantified by RT-qPCR.

We focussed on two main criteria for selecting the optimal number of pooled swabs: first, a higher viral load detected (i.e., a smaller Ct value), indicating that the impact of pooling on the test sensitivity is small; second, a larger pool size when the detected Ct values are similar, which can save consumables and man-hours. As is demonstrated in Fig.  4 a that when the number of swabs mixed was 10-in-1, the Ct value did not increase compared with a smaller pool size. The result of a pool size of 12 was larger than Ct 32, which may reduce the sensitivity in actual tests. Considering the above two factors, 10 pooled swabs was selected as the optimal pool size.

( a ) Detection results of two brands of inactivating and non-inactivating virus preservation solutions with different numbers of pooled swabs. ( b ) Detection results of different volumes of virus preservation solution for 10-in-1 pooled swabs.

Determining the optimal volume of virus preservation solution for swab pooling

The optimal volume of the two brands of virus preservation solution was determined on the basis of 10-in-1 pooled swabs. In the volume range from 5 to 17 mL, 7 groups of virus preservation solution were configured in 2 mL intervals and 10 swabs were added, one of which was a simulated positive sample swab soaked in a positive virus solution and the remaining nine were sampled healthy individuals. The pooled swabs were vortexed for 20 s, and 200 μL was removed for RNA extraction before detection by RT-qPCR. As is shown in Fig.  4 b, the XY10 + IS specimen with 9 mL virus preservation solution had the lowest Ct value. Meanwhile, the YK10 + IS specimen with 8 mL virus preservation solution had the second lowest Ct value. Thus, 9 mL XY virus preservation solution was determined as the optimal volume for the swab pooling strategy.

Determination of detection limit for swab pooling

Based on the optimal number of mixed swabs and the volume of virus preservation solution, the detection limit was determined by the number of viruses on individual positive swabs. Here, we used the RT-ddPCR method for accurate viral quantification. Our logic behind the use of RT-ddPCR for viral load detection and sensitivity was that this method gives absolute count of DNA molecules, eliminating the need to use and maintain reference material. The viral standard materials were diluted from 1000 copies/mL to 500/250/100/50/25/10 copies/mL. Swabs were completely immersed in a series of materials for 10 s and then placed in centrifuge tubes (50 mL volume) with 9 mL of virus preservation solution. Sixty-three swabs were used to sample healthy individuals and then placed into the centrifuge tubes described above, with 10 swabs per tube and vortexed for 20 s. Two hundred microliters were removed for RNA extraction, and then the amount of virus was quantified by RT-ddPCR to determine the detection limit. A positive swab at each virus dilution was added to 9 mL of virus preservation solution as a control.

Diluted viral materials from 1000 to 10 copies/mL were used to assess the sensitivity of pooling specimens. The limit of testing for pooling specimens was determined based on the threshold of RT-ddPCR. Based on the viral load of the single positive swab in 9 mL of viral solution, 50 copies/mL was found to be the test limit.

Determination of storage conditions for swab pooling

To analyze the effect of storage conditions on the pooled samples, we divided the samples in non-inactivating and inactivating virus preservation solution into three parts, two of which were placed at 4 °C and 25 °C, and the other one was placed at 4 °C after freeze-thawing twice. After 0 h, 12 h, 24 h and 48 h, 200 μL was removed from each sample for RNA extraction, and then the amount of virus was quantified by RT-qPCR. The results are shown in Fig.  5 . The viral load detected in the samples decreased significantly after freeze-thawing twice. The samples stored at 4 °C produced better results than those stored at 25 °C.

Assay results obtained for mixed samples under different storage conditions.

Sample validation for large-scale RT-qPCR screening

A number of 2342 low-risk individual samples were screened using the 10-in-1 pooled test, and no positive results had been tested. To evaluate the performance of the 10-in-1 pooled test, further, we collected 270 individual samples with epidemiological history of SARS-CoV-2, sampling 2 swabs at the same time, with one for a single-tube test and the other one for a 10-in-1 test. According to the RT-qPCR kit in a single-tube test, the Ct value less than or equal to 38 could be judged a positive result, which is regarded as a control. The 10-in-1 pooling test results show that all 262 negative samples and 7 positive samples could be correctly detected, though one of them was inconsistent with single-tube test results. Due to low viral load, the false-negative sample in 10-in-1 test Ct value greater than 38 and less than 40 was detected as the suspected sample, and it requires to be retested or sampled again.

The emergence of new SARS-CoV-2 variants with the waning of the pandemic has necessitated the need for accurate and rapid diagnostic and screening testing. In the context of a demand for SARS-CoV-2 testing in low-risk populations, swab pooling can improve screening efficiency and substantially reduce the need for sampling and testing kits while not considerably reducing the sensitivity of the test. However, pooling samples can be challenging, and various factors can influence the sensitivity of the screening procedure. Studies have shown that sensitivity decreases with increased pool size 29 . In addition, the efficiency of the pooled tests has been reported to depend on the viral load of the samples, the dilution of the sample 30 and also the transportation mode, storage and sensitivity of the kit 31 . In this study, we analyzed the main factors that influence the performance of pooled tests. Our pool size was smaller than 20 since a larger pool size has been reported to impact the accuracy of the test results and place an excessive burden on the sampling procedure 30 . Pooling swabs for testing does come with potential drawbacks. We have listed them in the manuscript. In addition, we have also included our sample collection procedure used in this study to minimize the variations.

Sampling swabs and virus preservation solutions play an important role in collecting specimens 32 . Our study revealed that flocked swabs are superior to fibre swabs because of their consistent scraping ability, absorption capacity, and release ability. The differences between the swabs may be related to the different materials and manufacturing principles. Fibre swabs are bound in layers and are not conducive to scraping epithelial cells and releasing viruses 30 . Flocked swabs are made by an electrostatic flocking process that attaches millions of nylon microfibers vertically to the swab head, facilitating sample collection, keeping the sample on the swab surface, and allowing for easier virus elution 29 .

Using of a virus preservation solution ensures the integrity of the virus and facilitates the accuracy of subsequent tests 33 . We investigated two types of virus preservation solutions currently available on the market, inactivating virus preservation solutions and non-inactivating virus preservation solutions. Inactivating virus preservation solution inactivates and lyses the virus with guanidine salts. It protects the operator from a secondary infection by the virus while preserving the integrity of the nucleic acid 32 . The purpose of the non-inactivating virus preservation solution is to preserve the intact structure of the virus, not only for nucleic acid extraction but also for virus culture 33 . Studies suggest that virus preservation solutions are almost always effective for virus detection, when the viral load is high. However, when the viral load is low, the non-inactivating virus preservation solution has a slight advantage. However, inactivating solutions can degrade viral RNA to some extent 27 .

In general, the bigger the pool size, the higher is the screening efficiency 27 . Considering the volume of the preservation tubes and swabs, we set the maximum number of mixed swabs at 20. To explore the optimal pool size and preservation solution volume, we collected products from major sample testing kit suppliers on the market and evaluated the pooled test performance using their swabs and virus preservation solutions. The number of swabs in the mix ranged from 1 to 20. To ensure that 20 swabs were fully immersed in the solution, we initially set the liquid volume of each tube to 15 mL, added only one positive swab per tube, and sampled the other swabs from healthy individuals. The healthy individuals in this study were those who had no clinical respiratory symptoms and was tested negative for other common respiratory pathogens detected by commercial kits.

Given the strong relationship between viral load and transmissibility of the SARS-CoV-2, accurate diagnostic testing is essential. Although quantitative reverse transcriptase PCR (qRT-PCR) has been recommended as the gold standard for COVID-19 diagnosis, it has been observed to have certain limitations. Studies have reported that the RT-qPCR results are limited by its reliance on a standard curve, sensitivity to inhibitors in clinical samples, and, more importantly, inconsistent performance at low concentrations. We used digital droplet PCR (RT-ddPCR) to determine the viral load from different pooled tests to assess the detection limit. Vasudevan et al. have demonstrated that RT-ddPCR can robustly quantify SARS-CoV-2 RNA from crude viral lysate 31 . From the viral load RT-qPCR results of the different pooled tests, we learned that the sensitivity of the assay has been guaranteed, and the efficiency of the assay has been improved when the number of pooled swabs is 10.

In determining the optimal volume of the virus preservation solution, we set up the volume in the 5 to 17 mL range at 2 mL intervals. Our results showed that 9 mL of virus preservation solution was optimal. The 5 mL pool volume could not thoroughly soak 10 swabs. Consequently, it could not completely release the virus on the swabs into the solution. For volumes greater than 9 mL, although the virus on the swab can be better released into the solution, it may dilute the virus concentration due to the larger volume, thus reducing the sensitivity of virus detection.

Although a larger pool size can improve the screening efficiency, it can also reduce the sensitivity of the assay 30 . Thus, we preferred 10 swabs in one preservation tube and 9 mL of preservation solution. Next, we proceeded to determine the limit of detection for this strategy. The final limit of detection was determined to be 50 copies/mL. It is crucial to perform a diagnostic analysis of the Ct value or copies of the test results during the implementation of pooled tests. In this study, we used both RT-qPCR and RT-ddPCR for evaluating of swab performance, viral load, and RNA preservation.

While screening large numbers of samples, it takes a long time to collect samples from the local field and transport them to the laboratory. This process prolongs the duration of the overall nucleic acid test. Under certain specific conditions, improper storage conditions of the samples may affect viral load. Therefore, we evaluated the effect of placing samples at different temperatures. The results showed little difference in viral load over 24 h storage at 4 °C and 25 °C. After 48 h, the result of 4 °C storage was slightly better than that of 25 °C storage. Therefore, sample storage for 48 h should have little effect on the sensitivity of the assay.

To reduce the influence of different sampling personnel on sample collection, these samples were taken by the same doctor, from the same collection site, with the same collection steps, and the same vortexing time, to minimize the differences introduced by the sampling process. If more sampling personnel are required, they would be rigorously trained with the same sampling procedures and quality controls 30 , 34 . The main drawback of our study is that it was conducted in a defined geographical area, and a viral load was adjusted experimentally or in standard mode used for adjusting 35 . in the laboratory. More studies and data from different geographical regions and samples from other SARS-CoV-2 variants risk areas are needed to validate our sample pooling strategies. In addition, we can expand the scope of such a study to assess its applicability to other respiratory viruses such as RSV and influenza. However, it's important to note that the effectiveness of pooling strategies can vary depending on the specific characteristics of each virus, including its stability, shedding patterns, and prevalence in the population. Therefore, while this research proposed pooling strategy may serve as a useful starting point, it would be prudent to conduct similar evaluations and optimizations tailored to the unique properties of RSV and influenza before widespread adoption. Nonetheless, this research stands as a promising foundation for future exploration and adaptation in the context of these viruses.

In conclusion, our study reveals that flocked swabs are a better choice than fibre swabs, 10 swabs pooled in one tube of 9 mL preservation solution gives better results, samples stored at 4 °C or 25 °C for up to 48 h has no significant effect on the sensitivity of virus detection, and virus preservation solutions do not have any effect on the efficiency and sensitivity of RT-qPCR or RT-ddPCR. We, therefore, recommend adopting a 10-in-1 pooling test for low-risk populations. If a positive result is found, the single-tube detection method can be used to track the epidemiological source.

Data availability

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

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Acknowledgements

This work was supported by the National Natural Science Foundation of China (82041027), High Level Public Health Technical Talent Training Plan (Talent plan-02-11, Talent plan-02-17), The Capital Health Development and Research of Special (2022-1G-3014), National Key R&D Program of China (2023YFC0872400, 2021ZD0114100, 2021ZD0114103), Beijing Science and Technology Planning Project of Beijing Science and Technology Commission (Z231100004823002, Z211100002521015, Z211100002521019), the Cultivation Fund of Beijing Center for Disease Prevention and Control (2020-BJYJ-22), Horizontal scientific research cooperation project (2022-jk-cd-021).

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Daitao Zhang: wrote the main manuscript text, prepared figures and tables, methodology, reviewed the manuscript. Lingyu Shen: wrote the main manuscript text, prepared figures and tables, methodology, reviewed the manuscript. Zhichao Liang: wrote the main manuscript text, prepared figures and tables, methodology, reviewed the manuscript. Shujuan Cui: wrote the main manuscript text, prepared figures and tables, methodology, reviewed the manuscript.

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Zhang, D., Shen, L., Liang, Z. et al. Evaluations of modes of pooling specimens for COVID-19 screened by quantitative PCR and droplet digital PCR. Sci Rep 14 , 10923 (2024). https://doi.org/10.1038/s41598-024-61631-0

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• First Trimester Screening Test Assesses Preeclampsia Risk

May 16, 2024 | Womens Health |

Labcorp has introduced a first trimester preeclampsia screening test to assess preeclampsia risk between 11- and 14-weeks’ gestation, enhancing early detection and management of this pregnancy complication.

• Innovative Screening : The new test measures four key biomarkers to predict preeclampsia with up to 90% sensitivity, significantly improving early risk assessment.
• Comprehensive Coverage : Labcorp is now the only lab offering preeclampsia risk screening across all pregnancy trimesters.
• Health Equity : This test is especially crucial for non-Hispanic Black women, who face a 60% higher preeclampsia risk compared to white women.

Labcorp , a provider laboratory services, announced the launch of its first trimester preeclampsia screening test to be performed between 11- and 14-weeks’ gestation to determine preeclampsia risk before 34 weeks of pregnancy. It is relevant for all pregnant individuals, including those with a low- to average-risk for preeclampsia or first-time pregnancies.

Preeclampsia is a high blood pressure disorder that can develop during pregnancy or postpartum and is a leading cause of maternal morbidity and mortality worldwide. Roughly one in 25 pregnancies in the U.S. is affected by preeclampsia, which poses an even greater risk for non-Hispanic Black women, who experience the condition at a 60% higher rate compared to white women.

Further Reading: Labcorp Launches Blood Test for Risk Assessment and Clinical Management of Preeclampsia

With this test launch, Labcorp is now the only laboratory to offer tests that screen for preeclampsia risk across all trimesters of pregnancy, according to the company. In January, Labcorp announced the launch and availability of an FDA-cleared blood test for risk assessment and clinical management of severe preeclampsia during the second and third trimesters.

“Our organization celebrates this innovative new test offering,” says Eleni Tsigas, chief executive officer of the Preeclampsia Foundation. “Research shows that patients and providers want access to more tools that better predict progression to preeclampsia, especially for those patients with low- to average-risk or those with first-time pregnancies for whom there is some uncertainty.”

Measuring Preeclampsia Risk

The first trimester test uses four key early pregnancy biomarkers to provide a comprehensive risk assessment with up to 90% sensitivity, nearly twice the sensitivity of assessing typical maternal history or biophysical factors alone. The test results provide risk identification earlier than traditional symptoms such as hypertension or protein in the urine, which tend to develop around 20-weeks’ gestation.

The blood-based test produces a risk score by measuring two biochemical markers—placental growth factor (PlGF) and pregnancy-associated plasma protein-A (PAPP-A)—and two biophysical markers—mean arterial pressure (MAP) and uterine artery pulsatility index (UtAPI). Low levels of PlGF and PAPP-A indicate poor placental development and function, while high MAP and UtAPI levels indicate high blood pressure and elevated resistance to blood flow across the uterine artery.

“Labcorp is committed to advancing maternal and fetal health through innovative diagnostic and screening solutions,” says Brian Caveney, MD, Labcorp’s chief medical and scientific officer. “This new first trimester blood test is another significant milestone in our mission to improve health and improve lives. By giving health care providers another tool to assess preeclampsia risk in their pregnant patients with objective biomarkers, we’re helping to advance prenatal care and improve outcomes for mothers and their babies.”

Data-Driven Testing

Labcorp’s test is based on published data from two principal studies, demonstrating the significant benefits of combining maternal factors with biomarkers for early screening. The SPREE study (Screening Program for Pre-eclampsia), a large prospective multicenter study of 16,700 women, reported that the combination of MAP, UtAPI, PlGF and PAPP-A yielded substantially improved screening performance than standard screening guidelines. The ASPRE trial (Combined Multimarker Screening and Randomized Patient Treatment with Aspirin for Evidence-Based Preeclampsia Prevention), a first trimester multicenter study of screening for preterm preeclampsia among more than 25,000 pregnant women, validated the use of MAP, UtAPI, PlGF and PAPP-A as screening factors.

The new first trimester test is the latest offering from Labcorp in its commitment to advance women’s health by providing innovative tests, resources and services to support each stage of an individual’s health journey. Among these services, Labcorp offers support to millions of women through its digital health platform, Ovia Health by Labcorp. Through its family of apps, Ovia offers evidence-based, clinically informed content and simple, convenient tools, including a preeclampsia prevention and management program, which provides members with clear, actionable guidance to help them understand their risk to make better health decisions that support a healthy pregnancy.

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BRETT D. THOMBS, PhD, Lady Davis Institute for Medical Research of the Jewish General Hospital, McGill University, Montreal, Quebec, Canada

SARAH MARKHAM, PhD, King's College London, London, United Kingdom

DANIELLE B. RICE, PhD, St. Joseph's Healthcare Hamilton, Hamilton, Ontario, Canada

ROY C. ZIEGELSTEIN, MD, Johns Hopkins University School of Medicine, Baltimore, Maryland

Am Fam Physician. 2024;109(5):391-392

Related Putting Prevention Into Practice:  Screening for Anxiety Disorders in Adults

Related U.S. Preventive Services Task Force Clinical Summary:  Screening for Anxiety Disorders in Adults

Author disclosure: No relevant financial relationships.

The U.S. Preventive Services Task Force (USPSTF) recommends that adults 19 to 64 years of age be screened for anxiety disorders, which include a number of disorders not commonly treated in primary care. 1 Adding anxiety screening tests, as well as clinician review and interpretation, to an already time-constrained primary care visit takes time away from critical health care tasks, increases administrative burden, and is not likely to benefit patients compared with good standard care.

For anxiety screening to be effective, several elements are required. First, patients must give consent and receive a properly administered screening test; if the result is positive, a diagnostic mental health assessment is required. Then, if a disorder is diagnosed, they must receive treatment that reduces symptoms more effectively than the absence of treatment, with any potential benefit outweighing any treatment-related harms. 2 , 3

The USPSTF did not identify any trials that fully tested anxiety screening in primary care. 1 Rather, it cited two randomized controlled trials that tested part of the process by enrolling patients who had already been screened and had positive results; in one group, results were shared with physicians, and in the second group, they were not. Trials that test only part of the screening process should more easily find benefit, but neither randomized controlled trial found evidence of improved mental health. 4 , 5

Treatment of generalized anxiety disorder (GAD), the most common anxiety disorder in primary care, mainly involves pharmacotherapy. 6 , 7 The USPSTF cited two randomized controlled trials that were described as having tested pharmacologic treatment in primary care. 8 , 9 One (n = 244) reported a small reduction in anxiety symptoms among patients randomized to venlafaxine XL compared with placebo, 8 and the other (n = 177) did not find any difference based on standard intention-to-treat analysis. 9 Neither trial included patients representative of a screened primary care population. GAD detected via screening in real-world primary care settings would presumably be less severe and less amenable to drug treatment than GAD among patients independently reporting symptoms or seeking treatment. 10 One of the trials cited by the USPSTF required participants to have higher levels of anxiety than almost all other GAD treatment trials that have been conducted, even though most of these trials have been completed in specialty mental health settings. 8 , 11 The other trial also restricted enrollment to patients with high symptom levels, and, contrary to the study's characterization by the USPSTF, most participants were not recruited from primary care settings. 1 , 9

The USPSTF downplayed harms from anxiety screening. 1 Increased prescriptions and use of anxiolytic medications can expose patients to adverse effects and drug-drug interactions related to polypharmacy, despite not having evidence of benefit in a screened population. 12 Antidepressants are the most common treatment for GAD, with a mean prescription duration of more than 5 years. 13 Benzodiazepines are also used long term for anxiety by many patients in primary care. 14 Antidepressant and benzodiazepine use can lead to severe discontinuation effects and be difficult to deprescribe. 15 , 16

The USPSTF added anxiety screening to other questionnaires it recommends routinely administering to screen for depression, unhealthy drug use, and intimate partner violence. Although these are significant concerns, there is no evidence that they are solvable by administering questionnaires. Neither the U.K. National Screening Committee nor the Canadian Task Force on Preventive Health Care recommends administering questionnaires to screen for these problems 17 , 18 ; there have been at least 20 trials of screening with questionnaires for a range of conditions, and none have shown an improvement in health outcomes. 19 For depression and intimate partner violence screening, several robust trials failed to find benefit. 2 , 3 , 19 , 20

If implemented as intended, each of the questionnaire-based screening procedures recommended by the USPSTF, including anxiety screening, would substantially increase the time required to provide care and the burden of documenting that care. 21 In addition to administering and scoring a screening test, anxiety screening would, at a minimum, require an initial evaluation of patients with positive results to evaluate the possible causes of symptoms. Among positive screens, some patients could have mild symptoms reflecting situational stressors or difficult life situations that are not resolvable through a diagnosis and prescription. Others could have symptoms due to a physical condition (e.g., thyroid disease) or lifestyle factor (e.g., caffeine intake). 22 Some patients could have anxiety disorders that are not typically treated in primary care. The amount of time needed for this evaluation could easily fill the allocated visit time for many patients. Some could be referred to a mental health specialist after an initial evaluation is performed, although not enough specialists are available to assess and care for all patients with anxiety disorders, and most patients would require additional time for management in primary care. 22

Too often, physicians enter the examination room with an ever-increasing checklist of items, making it difficult to hear and address the specific concerns of the patient. Rather than screening everyone with time-consuming questionnaires of unproven benefit, patients would be better served by being able to share their concerns, including those about mental health, with caring clinicians who take the time to talk with them, understand them as people, and help them access care options consistent with their needs, values, and preferences. 3

Editor's Note:  Dr. Thombs was supported by a Tier 1 Canada Research Chair. He was previously a member (2013 to 2021) and chair (2017 to 2021) of the Canadian Task Force on Preventive Health Care but did not serve as a voting member on mental health screening guidelines.

Barry MJ, Nicholson WK, Silverstein M, et al. Screening for anxiety disorders in adults: US Preventive Services Task Force recommendation statement. JAMA. 2023;329(24):2163-2170.

Thombs BD, Markham S, Rice DB, et al. Does depression screening in primary care improve mental health outcomes?. BMJ. 2021;374 : n1661.

Thombs BD, Markham S, Rice DB, et al. Screening for depression and anxiety in general practice. BMJ. 2023;382:1615.

Mathias SD, Fifer SK, Mazonson PD, et al. Necessary but not sufficient: the effect of screening and feedback on outcomes of primary care patients with untreated anxiety. J Gen Intern Med. 1994;9(11):606-615.

Kroenke K, Talib TL, Stump TE, et al. Incorporating PROMIS symptom measures into primary care practice—a randomized clinical trial. J Gen Intern Med. 2018;33(8):1245-1252.

Olfson M, Marcus SC, Wan GJ, et al. National trends in the outpatient treatment of anxiety disorders. J Clin Psychiatry. 2004;65(9):1166-1173.

Olfson M. The rise of primary care physicians in the provision of US mental health care. J Health Polit Policy Law. 2016;41(4):559-583.

Lenox-Smith AJ, Reynolds A. A double-blind, randomised, placebo controlled study of venlafaxine XL in patients with generalised anxiety disorder in primary care. Br J Gen Pract. 2003;53(495):772-777.

Lenze EJ, Rollman BL, Shear MK, et al. Escitalopram for older adults with generalized anxiety disorder: a randomized controlled trial. JAMA. 2009;301(3):295-303.

de Vries YA, Roest AM, Burgerhof JGM, et al. Initial severity and antidepressant efficacy for anxiety disorders, obsessive-compulsive disorder, and posttraumatic stress disorder: an individual patient data meta-analysis. Depress Anxiety. 2018;35(6):515-522.

Slee A, Nazareth I, Bondaronek P, et al. Pharmacological treatments for generalised anxiety disorder: a systematic review and network meta-analysis [published correction appears in Lancet . 2019; 393(10182): 1698]. Lancet. 2019;393(10173):768-777.

Maust DT, Sirey JA, Kales HC. Antidepressant prescribing in primary care to older adults without major depression. Psychiatr Serv. 2017;68(5):449-455.

Kendrick T. Strategies to reduce use of antidepressants. Br J Clin Pharmacol. 2021;87(1):23-33.

Tanguay Bernard MM, Luc M, Carrier JD, et al. Patterns of benzodiazepines use in primary care adults with anxiety disorders. Heliyon. 2018;4(7):e00688.

Davies J, Read J. A systematic review into the incidence, severity and duration of antidepressant withdrawal effects: are guidelines evidence-based?. Addict Behav. 2019;97:111-121.

Soyka M. Treatment of benzodiazepine dependence. N Engl J Med. 2017;376(12):1147-1157.

U.K. National Screening Committee. UK NSC recommendations. Accessed December 28, 2023. https://view-health-screening-recommendations.service.gov.uk/

Canadian Task Force on Preventive Health Care. Published guidelines. Accessed December 28, 2023. https://canadiantaskforce.ca/guidelines/published-guidelines/

Thombs BD, Rice DB, Markham S, et al. Depression screening in pregnancy and postpartum: just do something?. Gen Hosp Psychiatry. 2023;82:14-18.

Worster A, Lang E, Thombs BD, et al. Universal screening in the emergency department for intimate partner violence would consume scarce resources without improving patient well-being. CJEM. 2023;25(6):462-464.

Simon J, Panzer J, Wright KM, et al. Reduced accuracy of intake screening questionnaires tied to quality metrics. Ann Fam Med. 2023;21(5):444-447.

Stein MB, Hill LL. Are there reasons to fear anxiety screening?. JAMA. 2023;329(24):2132-2134.

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Cancer screening: what tests you should be doing and when

Posted: October 17, 2023 | Last updated: December 11, 2023

Cancer affects millions of people throughout the world. Though there are some things we can do to try and prevent it, such as adopting a healthy lifestyle, unfortunately this doesn't necessarily mean we'll be safe from cancer. For this reason,  running screening tests plays a crucial role in the early detection, treatment, and outcome of cancer . 

Click through the following gallery and get to know the most popular cancer screening tests and when/if you should get them done.  

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Raising awareness

In 2022, actors Ryan Reynolds and Rob McElhenney both got colonoscopies to raise awareness about colorectal cancer in people under 50. This is the third most frequently diagnosed cancer in the US.

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"It's not every day that you can raise awareness about something that will most definitely save lives. That's enough motivation for me to let you in on a camera being shoved up my [ ]," said Reynolds.

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Both Ryan Reynolds and the ‘It's Always Sunny in Philadelphia’ actor turned 45 this year. A colonoscopy is recommended at this age and can indeed save one’s life.

Screening tests

Now, let’s take a look at other cancer screening tests and when you should be doing them.

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Screening tests are performed in order to find cancer before any symptoms appear. This will allow for treatment, and vastly increases the likelihood of a successful recovery.

Breast cancer screening

Screening mammography is an x-ray of the breasts. It is used to detect signs of breast cancer.

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The recommended age to start screening varies, depending on risk factors as well as where you’re based in the world. In the US, for instance, it is recommended for women at age 50 (for those at an average risk level).

Cervical cancer screening

Human papillomavirus (HPV) tests and Pap tests (or pap smears) are essential to detect any abnormal cells that might evolve into cancer.

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Most women start this type of screening at age 21 and continue to do so throughout their lives until around age 65.

Colorectal cancer screening

A colonoscopy is the most popular screening test for colorectal cancer, though other tests are also used, namely sigmoidoscopies and stool tests.

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Screening starts at around age 45 and continues through to age 75. A colonoscopy is used to find abnormal colon growths (called polyps). These can then be removed before they become cancer.

Lung cancer screening

There is a specific type of CT scan that is used to screen for lung cancer. It’s called a low-dose helical computed tomography.

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People at risk, especially heavy smokers, should be screened, especially between the ages of 50 and 80.

Other screening tests

People who are at higher risk of certain cancers are sometimes prescribed other screening tests. Let’s take a look at some of them.

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Clinical breast exams and breast self-exams

These are the first line of prevention when it comes to detecting any abnormalities in breast tissue that will require further investigation.

Testicular cancer

There isn’t a specific screening test for testicular cancer, but similar to breast cancer, self-examination can help detect any bumps.

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An ultrasound may follow if something is detected. The risk group is primarily men aged between 15 and 40.

Colorectal cancer screening (virtual colonoscopy)

Unlike a regular colonoscopy, which is an invasive screening test, a virtual colonoscopy allows for the colon and rectum to be examined from the outside. This is done using CT scanning or magnetic resonance imaging.

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Liver cancer screening

There are two tests sometimes used to detect liver cancer. One is the alpha-fetoprotein blood test, and the other one is an ultrasound of the liver.

While a mammography is the first screening test used to detect any anomalies that can cause cancer, women who specifically carry a harmful mutation in either the BRCA1 or BRCA2 gene are usually subject to a breast MRI imaging test.

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This is because BRCA gene mutations put these women at higher risk of developing not only breast cancer, but also other types of cancers.

Ovarian cancer

This type of cancer is often diagnosed using two screening tests. These are a CA-125 blood test, and a transvaginal ultrasound.

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A transvaginal ultrasound is used to collect images of a woman’s ovaries and uterus, which can be useful not only for the detection of ovarian cancer, but also for endometrial cancer.

Prostate cancer screening

The screening for prostate cancer is usually done in two ways: through a prostate-specific antigen (PSA) blood test, and using a digital rectal exam.

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Skin cancer

Self-examining the skin is usually the first step when it comes to skin cancer prevention.

It is important to tell your doctor if a new mole appears, or if you notice any changes on an existing mole.

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Multicancer early detection tests

Multicancer early detection (MCED) tests measure biological signals in a blood sample. These signals, also known as biomarkers or tumor markers, may help detect different types of cancer.

MCEDs are not approved universally and its effectiveness is still being studied. If proven reliable and effective, in the future it may become a standard go-to screening test.

Sources: (National Cancer Institute) (CNN)

See also: Surprising things that can cause cancer

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NEST Previous Year Question Papers, Download NEST Old Question Papers

Nest previous year question papers | national entrance screening test | download nest previous year exam question papers/ nest question papers/ nest old question papers.

NEST Previous Year Question Papers: National Entrance Screening Test (NEST) is a compulsory test for students seeking admission to National Institute of Science Education and Research (NISER), Bhubaneswar and University of Mumbai – Department of Atomic Energy Centre for Excellence in Basic Sciences (UM-DAE CEBS), Mumbai. Here we have provided NEST previous year question papers for practice. Aspirants who want to got a seat need to secure high score in exam. NEST Previous year exam question papers for exam preparations to secure best marks. NEST Exam Previous Year Question Paper will assist you to get a clear idea about exam pattern, topics, etc. Students need to analyse the NISER NEST Previous Year Question Papers to know the strongest section. NEST Old questions papers, sample question papers, admission procedure are available at official website.

Both NISER and UM-DAE CEBS were set up by Department of Atomic Energy, Government of India in 2007. They will conduct the NEST 2022 exam in around 115 cities across India. Tracking the information regarding exams like exam notification, admit card, exam date sheet, etc. is essential. You may download the NEST Previous Year Question papers by clicking on given below link. It is an online/computer-based test for admission to the five-year Integrated MSc programme in Biology, Chemistry, Mathematics and Physics. Large number of students are attended the exam for every year. Admission will be done through merit list. Admission details, notification, sample questions, NEST previous year exam question papers are available @ official website. We hope this article will help you to get better results in your exams.

Detail of NEST Previous Year Exam Question Paper/ NEST Exam Old Question Papers

You may get the direct link to download NEST Exam previous year question papers here. Keep checking at www.dailyrecruitment.in for latest updates.

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• Risk Factors
• Resources to Share
• Ovarian Cancer Survivor Stories
• Increasing the Number of Women with Ovarian Cancer Who Are Treated by a Gynecologic Oncologist
• Gynecologic Cancers

Screening for Ovarian Cancer

• There is no reliable way to screen for ovarian cancer in women who do not have any symptoms.
• It is important to recognize symptoms and learn what you can do to reduce your risk.

What to know

There are no screening tests for ovarian cancer in women who do not have any signs or symptoms. The Pap test does not screen for ovarian cancer.

Screening is when a test is used to look for a disease before there are any symptoms. Diagnostic tests are used when a person has symptoms. The purpose of diagnostic tests is to find out, or diagnose, what is causing the symptoms. Diagnostic tests also may be used to check a person who is considered at high risk for cancer.

Since there is no simple and reliable way to screen for any gynecologic cancers except for cervical cancer, it is especially important to recognize symptoms and learn what you can do to reduce your risk .

Here is what you can do:

• Pay attention to your body, and know what is normal for you.
• If you notice any changes in your body that are not normal for you and could be a sign of ovarian cancer, talk to your doctor about them.

When to get tested

Ask your doctor if you should have a diagnostic test, like a rectovaginal pelvic exam, a transvaginal ultrasound, or a CA-125 blood test if you have any unexplained signs or symptoms of ovarian cancer. These tests sometimes help find or rule out ovarian cancer.

Ovarian Cancer

Learn about the symptoms and what you can do to reduce your risk.

For Everyone

Public health.