Measuring mammography compliance: lessons learned from a survival analysis of screening behavior

Data from a telephone survey of women participating in a federally funded screening program were used to demonstrate the sensitivity of mammography compliance estimates to varying definitions of the time interval within which women are considered compliant with screening guidelines and what constitutes a true screening (as opposed to diagnostic) mammogram. The survival analysis approach used reveals patterns concealed by other approaches to measuring mammography behavior and provides a means for quantifying the impact of various definitional choices on compliance estimates. The results suggest that, although variations in defining and excluding potential diagnostic mammograms lead to differences in compliance measures no greater than 6%, differences as small as 1 month in the screening interval definition used can produce differences in compliance estimates as large as 27%. These results call into question the comparability of estimates across studies and suggest that standard measures would greatly facilitate future efforts in understanding how to promote compliance with mammography screening guidelines.