Patterns and characteristics of repeat mammography among women 50 years and older

Whereas efforts encouraging women to obtain initial mammograms are laudable , the importance of returning for subsequent routine mammograms cannot be m inimized. The purpose of this study was to measure the timing, patterns, an d characteristics of repeat screening mammography over time in a defined po pulation of health maintenance organization members for whom mammography wa s a fully covered benefit, We identified all women ages 50-74 years who wer e enrolled in a southeastern Michigan health maintenance organization, assi gned to a large medical group, and received at least one screening mammogra m with a normal result between January 1, 1989 and December 31, 1996, Using administrative and radiology data, we calculated the proportion of women w ho received a subsequent mammogram within 2 Sears and the time to subsequen t screening, both overall and stratified by demographic characteristics. We also examined screening patterns over a 5-year period. Of the 8749 women i ncluded in this study, 66.0% [95% confidence interval (CI), 65.0-67.0%] wer e subsequently screened within 2 years. We found slightly higher rates amon g Caucasians and married women. The proportion of women who received repeat mammography increased with estimated household income [9.5% difference bet ween the highest and lowest categories (95% CI, 6.5-12.5%)]. The median tim e to subsequent screening was 17.7 months, and the probability of repeat sc reening was higher for women whose initial mammogram was between January 19 92 and December 1994 compared to those receiving an initial mammogram betwe en January 1989 and December 1991 (9.6% difference; 95% CI, 7.5-11.7%). Rep eat mammography has improved over time; however, socioeconomic status could contribute to longer-than-intended intervals between screening when transl ated into real-world clinical practice. In a setting where most physicians recommended annual screening, we found that the median time to subsequent s creening was delayed by 6 months. If annual mammography is the goal, recomm endations should be made with the understanding of how the timing of repeat screening occurs in clinical practice.