Investigating reversals of association for utilization of recent mammography among Hispanic and Non-Hispanic Black women

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.