Effect of racial/ethnic misclassification of American Indians and Alaskan natives on Washington state death certificates, 1989-1997

Objectives. This study examined effects of racial/ethnic misclassification of American Indians and Alaskan natives on Washington State death certificates, Methods. Probabilistic record linkage were used to match the 198-1997 state death files to the Northwest Tribal Registry. Results. We identified matches for 2819 decedents, including 414 (14.7%) who had been misclassified as non-American Indians and Alaskan natives on the death certificates. The likelihood of being correctly classified increased 3-fold for each higher level of American Indian and Alaskan native ancestry (odds ratio = 2.88; 95% confidence interval [Cl] = 2.51, 3.30) and decreased by 6.9% per calendar year (95% Cl = 2.0, 11.5). Conclusions. Systematic biases on death certificates in Washington State persist. Methods to reduce misclassification can improve data quality and enhance efforts to measure and reduce racial/ethnic health disparities.