In the last ten years several reports using a variety of health data sets have shown a high proportion of racial misclassification for Northwest American Indians and Alaskan Natives (AI/ANs). The result of this has been an underestimation of the burden of various diseases among Northwest AI/ANs. To address health issues related to misclassification, the Northwest Tribal Epidemiology Center has developed the Northwest Tribal Registry (NTR), which contains a demographic data set of 135,060 Northwest AI/ANs, and which can be used for record linkage studies to ascertain accurate disease rates for Northwest AI/ANs. However, the Seattle Indian Health Board Registration contains a large number of Northwest AI/ANs, and it has not yet been incorporated into the NTR. To ascertain the degree of concordance between the NTR and SIHB Registration, we conducted a record linkage study linking these two files. RESULTS: Of the 23,337 entries in the SIHB Registration, only 7,005 (30%) linked or matched with the NTR, leaving 16,332 who were not matched. Among the SIHB-NTR matches, 1,597 (22.8%) were from Northwest tribes; among the SIHB-NTR non-matches, only 3,413 (20.9%) were from Northwest tribes. CONCLUSION: The NTR is missing information on a substantial number of AI/ANs who have utilized the Seattle Indian Health Board for health care services. However, less than a fourth of these individuals are from Northwest tribes served by the Northwest Portland Area Indian Health Board.
Northwest Portland Area Indian Health Board, Portland, Oregon.
Bettles J. Robertson D. Romero FC. Becker T. Stehr-Green P. Northwest Tribal Registry--Seattle Indian Health Board Record Linkage Project. Northwest Portland Area Indian Health Board, Portland, Oregon. 15-Nov 1999