Va. Lawrence et al., Systematic differences in validity of self-reported mammography behavior: A problem for intergroup comparisons?, PREV MED, 29(6), 1999, pp. 577-580
Background Prior studies of recall accuracy for screening mammogram behavio
r have examined relatively homogeneous groups. Data are limited on possible
systematic group differences, so we evaluated women's recall accuracy in t
wo separate care systems in one city.
Methods. Women 50 to 70 years old with and without screening mammograms 10
to 14 months prior were identified from fiscal, clinic, and radiology recor
ds at a military care system (MCS) and a county-funded system (CFS) for ind
igents. Mammogram status was verified through radiology records. Women were
excluded if mammograms were diagnostic, done for other than annual screeni
ng, or had abnormal results. Interviewers blinded to mammogram status surve
yed randomly selected eligible women.
Results. For 62 screened/31 unscreened MCS women and 78 screened/61 unscree
ned CFS women, specificity was similar, at 65 and 62%, respectively. In con
trast, sensitivity varied significantly: 95% versus 79% (P = 0.011). Primar
y ethonocultural groups were Euro-American (MCS-60%) and Mexican American (
CFS-85%)Although not different in specificity of recall (67% versus 61%), t
hese major subgroups significantly differed insensitivity (97% versus 80%,
P = 0.017), proportion of true negatives due to never having a mammogram (3
5% versus 57%, P = 0.003), and proportion with greater than or equal to hig
h school education (78% versus 19%, P < 0.00001).
Conclusion. Systematic differences in recall validity may exist and comprom
ise the accuracy of intergroup comparisons. (C) 1999 American Health Founda
tion and Academic Press.