Methods. The two face-to-face interviews were spaced an average of 2.6 years apart. Baseline and follow-up reports were compared, with adjustments made for interval mammography use. The consistency of reporting was evaluated in several ways.
Results. Two-thirds of the women reported their lifetime number of mammograms reliably to within one mammogram. Consistency decreased with increasing lifetime report, and women of disadvantaged background reported with higher consistency.
Conclusions: These findings may provide population researchers with a better understanding of the reliability of self-reported mammography use, and may help physicians estimate the probable reliability of individual patient reports. Accurately measuring lifetime adherence to mammography guidelines could help both researchers and clinicians assess the long-term effect of interventions
