Race and medication adherence in Medicaid enrollees with type-2 diabetes.

OBJECTIVE

The association of medication adherence with race has been inadequately studied previously in type-2 diabetes patients. The study objective was to determine the association between race and medication adherence among type-2 diabetes patients.

METHODS

This was a retrospective cohort study, which compared medication adherence among different races of Medicaid insured patients with type-2 diabetes newly starting oral antidiabetic medication. A total of 1,527 African-American patients newly starting antidiabetic medication between July 2001 and June 2002 were compared with 1,128 white patients and 514 patients of other race. Medication adherence was measured as medication possession ratio using prescription refill patterns. Multivariate regression analyses were used to determine the difference in adherence rates adjusting for other covariates.

RESULTS

Medication adherence rate was significantly higher for whites [0.59 (0.31)] as compared to African Americans [0.54 (0.31), (p<0.05)]. In multivariate analyses, the adherence rate of African-American patients was found to be significantly lower by 12% as compared to whites after adjusting for other covariates. Metformin users were associated with a 62% decrease in adherence rate as compared with the sulfonylureas group (p<0.05).

CONCLUSION

The antidiabetic medication adherence was associated with race. Future research should investigate patient-related factors affecting medication adherence in type-2 diabetes patients.