Use of Medicare and DOD data for improving VA race data quality.

We evaluated the improvement in Department of Veterans Affairs (VA) race data completeness that could be achieved by linking VA data with data from Medicare and the Department of Defense (DOD) and examined agreement in values across the data sources. After linking VA with Medicare and DOD records for a 10% sample of VA patients, we calculated the percentage for which race could be identified in those sources. To evaluate race agreement, we calculated sensitivities, specificities, positive predictive values (PPVs), negative predictive values, and kappa statistics. Adding Medicare (and DOD) data improved race data completeness from 48% to 76%. Among older patients (≥65 years), adding Medicare data improved data completeness to nearly 100%. Among younger patients (<65 years), combining Medicare and DOD data improved completeness to 75%, 18 percentage points beyond that achieved with Medicare data alone. PPVs for white and African-American categories were 98.6 and 94.7, respectively, in Medicare and 97.0 and 96.5, respectively, in DOD data using VA self-reported race as the gold standard. PPVs for the non-African-American minority groups were lower, ranging from 30.5 to 48.2. Kappa statistics reflected these patterns. Supplementing VA with Medicare and DOD data improves VA race data completeness substantially. More study is needed to understand poor rates of agreement between VA and external sources in identifying non-African-American minority individuals.