Objective: Several papers have found that Hispanic and Non-Hispanic Black women have higher adjusted odds ratios for recent mammography when compared with Non-Hispanic White women, even though their crude percentages were lower than, or about equal to, Non-Hispanic White women's. This paper investigates the existence of "reversals" of association for recent mammography and describes an analysis strategy for identifying variables that might produce them.
Methods: We used every-other-year data for women aged 40-80 from the 1996-2006 Behavioral Risk Factor Surveillance System and the 1999, 2000, 2003, and 2005 National Health Interview Survey. A consistent set of covariates was used across all datasets.
Results: Reversals were found in almost all survey years for Hispanic women. Non-Hispanic Black women often had unadjusted rates comparable to Non-Hispanic Whites, but their adjusted odds ratios were significantly higher in most surveys. A limited number of variables contributed strongly to reversals, and differed somewhat for Hispanic and Black women.
Conclusions: Reversed associations found in adjusted analyses present a challenge for interpretation, but could also denote success of programs to increase screening rates. Users of population-level surveys should be alert for reversals and attempt to find explanations.