Volume 50 | Number S1 | August 2015

Abstract List

Kristyn M. Bigback M.P.H., Megan Hoopes M.P.H., Jenine Dankovchik, Elizabeth Knaster M.P.H., Victoria Warren‐Mears Ph.D., Sujata Joshi M.S.P.H., Thomas Weiser M.D.


To evaluate and adjust for American Indian and Alaska Native (/) racial misclassification in two hospital discharge datasets in the Pacific Northwest.

Data Sources/Study Setting

Oregon (2010‐2011) and Washington (2011) hospital discharge datasets were linked with the Northwest Tribal Registry (), a registry of / individuals who accessed services at Indian health facilities in the Northwest.

Study Design

Record linkage was used to match state hospital records to the . A state record was considered misclassified if it matched the and was coded as non‐/ or missing race data. Effect of misclassification was evaluated by comparing prelinkage and postlinkage, age‐adjusted hospital discharge rates.

Data Collection/Extraction Methods

Researchers used software (Atlanta, GA, USA) for linkages and (Cary, NC, USA) for statistical analyses.

Principal Findings

In Oregon, 55.4 percent of matching records were misclassified (66.5 percent miscoded white, and 22.1 percent were missing race information). In Washington, 44.9 percent of matching records were misclassified (61.8 percent miscoded white, and 32.7 percent were missing race information). Linkage increased ascertainment of / hospitalizations by 31.8 percent in Oregon and 33.9 percent in Washington. Linkage increased the rate ratio () for / hospitalizations in comparison to non‐Hispanic whites () from 0.81 to 1.07 in Oregon, and from 1.21 to 1.62 in Washington.


Correction of race in hospital discharge datasets through linkage with a reference file of known / individuals is an important first step before analytic research on / health care in the Pacific Northwest can be accomplished with administrative datasets.