April 2014 Clinical Laboratory News: Volume 40, Number 4
The Promise of Home-Based Specimen Collection
Home Kits Offer Timelier Diagnoses, Increased Participation in Cancer Screening
An interview with Sharon M. Geaghan, MD
Home test collection kits are sold over-the-counter (OTC) and allow the individual to self-collect and send a sample to a laboratory for analysis and result interpretation. Collecting a sample at home is usually less time-consuming than making a clinic visit, offering both convenience and a greater degree of anonymity. Here, Sharon M. Geaghan, MD, discusses how research has demonstrated that these advantages can improve the success of public health screening programs and potentially lead to decreased morbidity and mortality from both infectious diseases and cancer.
Dr. Geaghan is a professor of pathology and pediatrics at Stanford University School of Medicine in Palo Alto, Calif.
Bill Malone conducted this interview.
How well do patients collect samples at home?
Patients do better than some laboratorians might expect. Several lines of research indicate that self-collection at home can be performed successfully and reliably. For example, home nasal swab self-collection may offer timelier respiratory virus diagnosis. In a feasibility study of home nasal swab collection in cystic fibrosis patients presenting with new respiratory illness, diagnostic yield for respiratory pathogen was compared between flocked swabs collected at home, versus those collected by research staff. Home-collected swabs had a higher pathogen positivity rate (81%) compared with clinic-collected swabs (50%). This is likely because home collection occurred closer to illness onset, as these swabs were submitted 2.3 symptom days sooner than clinic collection (1). I believe that this novel home-based approach for clinical diagnostics and surveillance of respiratory virus infections among cystic fibrosis patients has potential for expansion to other user groups.
Is there an evidence base linking home test collection to outcomes?
Absolutely. In public health programs, web-based recruitment and home-based sample collection appear to be powerful new tools for surveillance, treatment, and prevention of sexually transmitted diseases. Home-based sampling has been shown to increase participation in sexually transmissible infection screening programs. For example, the majority of genital Chlamydia trachomatis infections are asymptomatic, so many patients do not seek testing. This has two unfavorable consequences: active infections remain undiagnosed and untreated, and transmission of these infections continues. In one example, a population-based randomized controlled trial in Norway of individuals ages 18–25 years demonstrated the positive effect of systematic screening. Researchers sent information by mail and an invitation to provide urine by home sampling with a mail-back kit. This approach resulted in 2.6 times more young people being diagnosed and 2.5 times more people being treated for chlamydia in the 3 months following the intervention compared to the current clinic-based testing strategy in that healthcare system (2).
Are there examples of public health screening programs using home collection kits in the U.S.?
There are several. Public health scientists investigated whether accepting self-collected penile samples could help recruitment of men at risk for sexually transmitted infections. First, sexually active males at least 14 years old were recruited by an educational website and offered free testing for Trichomonas vaginalis infection. Men could order kits online and return swabs by U.S. mail to the laboratory for nucleic acid amplification testing. Risk factors for trichomonas infection were determined by multivariate logistic regression based on a questionnaire about demographics and risk factors. Of those who requested kits, 38.6% returned swabs by mail over the multi-year study, with an overall prevalence for trichomonas of 3.7%. This shows that web-based recruitment for Trichomonas vaginalis screening produces a fairly high yield for disease, and may enhance screening practices. In individuals with risk factors, the incidence was even higher, 9.6% (3).
In fact, analysis of home based self-collection literature for sexually transmitted infections found that—across the board—in comparison to clinic-based methods, home-based screening significantly increases participation in screening programs for chlamydia, gonorrhoea, and trichomoniasis in females. Users in several trials also expressed a significant preference for home-based testing. Importantly, no significant difference was observed in specimen quality (4).
Where do you see the biggest impact for home collection programs?
Home collection programs have the potential to save lives by improving early detection of cancer. The majority of cervical cancers, for example, can be successfully treated if detected early. Non-participation in cervical screening programs is the major determinant in the risk of mortality due to cervical cancer. For instance, in Sweden, approximately 65% of women with cervical carcinoma have not participated in organized screening. To increase participation, Swedish researchers launched a program that recruited women for self-sampling at home, in combination with a test for high-risk human papilloma virus (HPV), a necessary factor for cervical cancer development. The program targeted women who had had no screening for at least 6 years. About 40% of the women accepted home sampling and the participation rate in cervical screening programs increased dramatically. Almost twice as many women with pre-malignant cell alterations were detected, compared to a single cytological Pap smear (5).
Those findings are remarkable. Have they been confirmed by other studies?
Yes, two in particular come to mind. In France, about 40% of women do not participate in regular screening, with one of the most common reasons being refusal of gynecological examination. This study included 9,334 women who did not have a Pap test during the 2 previous years and who did not respond to a first invitation. These non-responders were randomized into two groups: the first received an offer to receive and perform an HPV self-test at home, while the second received a repeat invitation to have a Pap smear at clinic. The response rate to self-collect (26.4%) was markedly higher than the second invitation for the Pap test (7.2%). Such a self-collection strategy can increase participation in cervical screening programs, which can reduce cervical cancer risk, and has the potential to save lives (6).
In addition, a pilot study in the Appalacian region of the United States assessed acceptability of a take-home fecal immunochemical test and educational pamphlet, and the effect of follow-up telephone counseling for increasing screening rates. Home-based telephone recruitment proved to be successful, engaging the 28% of patients who were non-adherent. About 41% became adherent after one to two counseling sessions, for an 11.5 percentage-point increase in screening after telephone counseling and 84% adherence overall. This study demonstrates the feasibility and acceptability of self-sampling in the home when combined with telephone counseling, especially for a resource-poor community (7).
What is the role of laboratorians in this home-based collection kit model?
We serve as expert advisors in diagnostic testing. As clinical laboratory medicine expands to the point-of-care in professional healthcare settings and into the medical home, we will continue to be consulted as domain experts in the field.
In addition to the analytic testing and interpretation of test results from home-based collection kits, there are new professional opportunities offered by an increase in home test collection. Laboratorians are essential to successfully implementing self-collection programs and designing community-based or patient-centered recruitment efforts to increase participation in cancer and other screening programs.
1. Emerson J, Cochrane E, McNamara S, et al. Home self-collection of nasal swabs for diagnosis of acute respiratory virus infections in children with cystic fibrosis. J Pediatric Infect Dis Soc 2013;2:345–51.
2. Kløvstad H, Natås O, Tverdal A, et al. Systematic screening with information and home sampling for genital Chlamydia trachomatis infections in young men and women in Norway: A randomized controlled trial. BMC Infect Dis 2013;13:30.
3. Gaydos CA, Barnes MR, Quinn N, et al. Trichomonas vaginalis infection in men who submit self-collected penile swabs after internet recruitment. Sex Transm Infect 2013;89:504–8.
4. Odesanmi TY, Wasti SP, Odesanmi OS, et al. Comparative effectiveness and acceptability of home-based and clinic-based sampling methods for sexually transmissible infections screening in females aged 14–50 years: A systematic review and meta-analysis. Sex Health 2013;10:559–69.
5. Sanner K, Wikström I, Strand A, et al. Self-sampling of the vaginal fluid at home combined with high-risk HPV testing. Br J Cancer 2009;101:871–4.
6. Piana L, Leandri FX, Le Retraite L, et al. HPV-Hr detection by home self-sampling in women not compliant with pap test for cervical cancer screening. Results of a pilot programme in Bouches-du-Rhône. Bull Cancer 2011;98:723–31.
7. Kluhsman BC, Lengerich EJ, Fleisher L, et al. A pilot study for using fecal immunochemical testing to increase colorectal cancer screening in Appalachia, 2008–2009. Prev Chronic Dis 2012;9:E77.