Breast cancer screening outreach effectiveness: Mammogram-specific reminders vs. comprehensive preventive services birthday letters.

We compared the effectiveness of two outreach strategies on timely mammography adherence: a mammogram-specific reminder letter (sent just before a woman was due) to a birthday letter (addresses multiple preventive services and not timed around due dates). We evaluated screening mammography adherence following 79,848 mammogram-specific and 151,626 birthday letters mailed between 2002 and 2012 to women aged 40-74years enrolled in Kaiser Permanente Washington. Screening mammogram adherence was specifically tied to due date and was evaluated separately by age group and up-to-date or overdue status at the time of mailing. We used generalized estimating equations to account for correlation between repeated observations, to model the odds of screening mammography adherence by letter type. Among women up-to-date, adherence following birthday letters was 22-76% lower compared to the mammogram-specific reminders, with the greatest decreases in adherence in women aged 70-74. Birthday letters were more effective at activating screening uptake among some subgroups of overdue women aged 50-69 and most overdue women aged 70-74, but universally low adherence rates were observed in overdue women. Increasing number of recommended services for women aged 50-74 who were up-to-date resulted in 12-17% lower mammography adherence, but had no effect in women aged 40-49 or in overdue women. Birthday letters are less effective than mammogram-specific reminder letters at prompting women to undergo timely breast cancer screening, particularly among women up-to-date with screening. Birthday letters may be effective at increasing overall preventive care; however, supplemental outreach may be needed around the due date to increase timely preventive services receipt.