Strategies to Increase Cervical Cancer Screening With Mailed Human Papillomavirus Self-Sampling Kits: A Randomized Clinical Trial

IMPORTANCE Optimal strategies for increasing cervical cancer screening may differ by patient screening history and health care setting. Mailing human papillomavirus (HPV) self-sampling kits to individuals who are overdue for screening increases adherence; however, offering self-sampling kits to screening-adherent individuals has not been evaluated in the US. OBJECTIVE To evaluate the effectiveness of direct-mail and opt-in approaches for offering HPV self-sampling kits to individuals by cervical cancer screening history (screening-adherent and currently due, overdue, or unknown). DESIGN, SETTING, AND PARTICIPANTS Randomized clinical trial conducted in Kaiser Permanente Washington, a US integrated health care delivery system. Individuals aged 30 to 64 years with female sex, a primary care clinician, and no hysterectomy were identified through electronic health records (EHRs) and enrolled between November 20, 2020, and January 28, 2022, with follow-up through July 29, 2022. INTERVENTIONS Individuals stratified as due (eg, at the time of randomization, these individuals have been previously screened and are due for their next screening in <= 3 months) were randomized to receive usual care (patient reminders and clinician EHR alerts [n=3671]), education (usual care plus educational materials about screening [n=3960]), direct mail (usual care plus educational materials and a mailed self-sampling kit [n=1482]), or to opt in (usual care plus educational materials and the option to request a kit [n=3956]). Individuals who were overdue for screening were randomized to receive usual care (n=5488), education (n=1408), or direct mail (n=1415). Individuals with unknown history for screening were randomized to receive usual care (n=2983), education (n=3486), or to opt in (n=3506). MAIN OUTCOMES AND MEASURES The primary outcome was screening completion within 6 months. Primary analyses compared direct-mail or opt-in participants with individuals randomized to the education group. RESULTS The intention-to-treat analyses included 31355 randomized individuals (mean [SD] age, 45.9 [10.4] years). Among those who were due for screening, compared with receiving education alone (1885 [47.6%]), screening completion was 14.1% (95% CI, 11.2%-16.9%) higher in the direct-mail group (914 [61.7%]) and 3.5% (95% CI, 1.2%-5.7%) higher in the opt-in group (2020 [51.1%]). Among individuals who were overdue, screening completion was 16.9% (95% CI, 13.8%-20.0%) higher in the direct-mail group (505 [35.7%]) compared with education alone (264 [18.8%]). Among those with unknown history, screening was 2.2% (95% CI, 0.5%-3.9%) higher in the opt-in group (634 [18.1%]) compared with education alone (555 [15.9%]). CONCLUSIONS AND RELEVANCE Within a US health care system, direct-mail self-sampling increased cervical cancer screening by more than 14% in individuals who were due or overdue for cervical cancer screening. The opt-in approach minimally increased screening. To increase screening adherence, systems implementing HPV self-sampling should prioritize direct-mail outreach for individuals who are due or overdue for screening. For individuals with unknown screening history, testing alternative outreach approaches and additional efforts to document screening history are warranted.