Comparative effectiveness of two outreach strategies for cervical cancer screening

Test-specific reminder letters can improve cancer screening adherence. Little is known about the effectiveness of a reminder system that targets the whole person by including multiple screening recommendations per letter.

We compared the effectiveness of a Pap-specific reminder letter sent 27months after a woman's last Pap, to a reminder letter that included up to seven preventive service recommendations sent before a woman's birthday ("birthday letter") on Pap smear adherence from a natural experiment occurring in routine clinical care. Participants included 82,016 women from Washington State who received 72,615 Pap-specific letters between 2003 and 2007 and 100,218 birthday letters between 2009 and 2012. We defined adherence as having a Pap test within a six month window around the Pap test due date. Using logistic regression, we calculated adjusted odds ratios (OR) for adherence with 95% confidence intervals (CI) following the birthday letter with 1-2 recommendations, 3-5 recommendations, and 6-7 recommendations compared to the Pap-specific letter. All analyses were stratified by whether a woman was up-to-date or overdue for screening at the time she received a letter.

Adjusted ORs showed reduced adherence following the birthday letter compared with the Pap-specific letter for up-to-date women whether the letter had 1-2 recommendations (OR=0.37, 95%CI=0.36-0.39), 3-5 recommendations (OR=0.44, 95%CI=0.42-0.45), or 6-7 recommendations (OR=0.36, 95%CI=0.32-0.40). We noted no difference in Pap-test adherence between letter types for overdue women.

In conclusion, for women regularly adherent to screening, an annual birthday letter containing reminders for multiple preventive services was less effective at promoting cervical cancer screening compared with a Pap-specific letter.