Comparing cancer screening estimates: Behavioral Risk Factor Surveillance System and National Health Interview Survey

Cancer screening prevalence from the Behavioral Risk Factor Surveillance System (BRFSS), designed to provide state-level estimates, and the National Health Interview Survey (NHIS), designed to provide national estimates, are used to measure progress in cancer control. A detailed description of the extent to which recent cancer screening estimates vary by key demographic characteristics has not been previously described. We examined national prevalence estimates for recommended breast, cervical, and colorectal cancer screening using data from the 2012 and 2014 BRFSS and the 2010 and 2013 NHIS. Treating the NHIS estimates as the reference, direct differences (DD) were calculated by subtracting NHIS estimates from BRFSS estimates. Relative differences were computed by dividing the DD by the NHIS estimates. Two-sample t-tests (2-tails), were performed to test for statistically significant differences. BRFSS screening estimates were higher than those from NHIS for breast (78.4% versus 72.5%; DD=5.9%, p<0.0001); colorectal (65.5% versus 57.6%; DD=7.9%, p<0.0001); and cervical (83.4% versus 81.8%; DD=1.6%, p<0.0001) cancers. DDs were generally higher in racial/ethnic minorities than whites, in the least educated than most educated persons, and in uninsured than insured persons. For example, the colorectal cancer screening DD for whites was 7.3% compared to ≥8.9% for blacks and Hispanics. Despite higher prevalence estimates in BRFSS compared to NHIS, each survey has a unique and important role in providing information to track cancer screening utilization among various populations. Awareness of these differences and their potential causes is important when comparing the surveys and determining the best application for each data source.