Disparities in type 2 diabetes-associated hospitalization among American Indians/Alaska Natives and other races, Washington, 2007-2008

Background: The prevalence of diabetes among American Indians and Alaska Natives (AI/AN) in Washington State is almost double that of the general population (12.0% versus 6.3%), potentially exposing AI/AN to higher rates of hospitalization due to diabetes. We examined disparities in diabetes-associated hospitalization for Washington's AI/AN population, after correcting race coding in discharge data through record linkage with two Indian health organizations. Methods: We corrected race coding in Washington hospital discharge data for 5/1/2007 – 12/31/2008 using probabilistic record linkage to a file representing Washington's urban and tribal AI/AN population. We examined admissions with type 2 diabetes as the primary diagnosis and other primary diagnoses with type 2 diabetes indicated as a comorbid condition. Results: Among patients 15 years and older, a significantly greater proportion of AI/AN admissions were due to type 2 diabetes, compared to other races combined (1.7% versus 0.8%, respectively; p<0.01). The age-adjusted rate of admission due to type 2 diabetes was 17.0 per 10,000 (95% CI: 14.0 – 20.5) for AI/AN, versus 7.9 (95% CI: 7.6 – 8.1) for other races. For admissions for other primary causes, type 2 diabetes was a comorbid diagnosis in a significantly higher proportion of AI/AN admissions (18.1% versus 14.5%). While comorbid type 2 diabetes was associated with circulatory, respiratory, and skin conditions in both groups, AI/AN had a high proportion of primary cellulitis and abscess. Conclusions: Rates of hospitalization associated with type 2 diabetes are disproportionately high for Washington AI/AN, highlighting the importance of accurate racial classification to reveal and address health disparities.