Women who delay Pap screening are at increased risk for cervical cancer. In countries with organized screening programs, population-based randomized controlled trials (RCTs) have shown that mailing HPV self-sampling kits to underscreened women increases participation. Our objective was to evaluate the effectiveness of this approach in a U.S. healthcare system.
We conducted a pragmatic RCT within Kaiser Permanente Washington (an integrated healthcare system) to compare 2 programmatic approaches for increasing screening among women aged 30-64 years who were overdue (≥3.4 years since last Pap). The control arm included usual care (annual patient reminders and ad hoc outreach by clinics). The intervention arm included usual care plus a mailed self-sampling kit for HPV testing by Roche Cobas assay. Women and their healthcare providers were notified of the home HPV results and providers were responsible for encouraging women to receive appropriate follow-up: diagnostic colposcopy if HPV16/18+ and additional in-clinic screening (Pap or co-test) if unsatisfactory or positive for non-HPV16/18 types. Unlike similar trials in other countries, HPV-negative women were still recommended to receive in-clinic screening because home HPV testing is not an approved screening strategy in the U.S. Screening uptake was defined as any of the following within 6 months of randomization: 1) in-clinic screening; 2) returning a kit that was HPV-negative or HPV16/18+; or 3) returning a kit that was unsatisfactory or positive for non-HPV16/18 types, followed by in-clinic screening.
From 2014- 2016, we randomized 16,242 women (8116 control; 8126 intervention) with a median age of 51 years. Screening uptake was higher in the intervention than control arm (28.3% vs. 19.5%; relative risk=1.45, 95%CI:1.37-1.54). Within the intervention arm, 13.1% of women returned a kit and 15.4% attended in-clinic screening without returning a kit. 11.5% of self-sampling kits were HPV+ (3.1% HPV16/18+ and 8.4% positive for non-HPV16/18 types only).
Mailing HPV self-sampling kits to underscreened women increased screening uptake compared to usual care alone. Screening uptake in our intervention arm was comparable to pooled uptake from a meta-analysis of non-U.S. trials (28.3% vs. 23.6%).[1] Our results suggest that approximately half of women who choose to get screened after receiving a mailed home HPV kit will choose in-clinic screening over self-sampling in a hybrid screening approach. Additional findings from this study will describe clinical outcomes, demographic and health predictors of screening uptake, and self-sampling experiences and attitudes.
1. Verdoot et al. Reaching women who do not participate in the regular cervical cancer screening programme by offering self-sampling kits: a systematic review and meta-analysis of randomised trials. Eur J Cancer. 2015: 51 (16) 2375-85.
ClinicalTrials.gov, NCT02005510