Objective: To investigate whether Medicare and/or Medicaid beneficiaries with behavioral health disorders (BHDs) receive lower quality diabetes care.

Study Design: Retrospective observational study using merged Medicare and Medicaid claims data from Massachusetts in calendar years 2004 and 2005.

Methods: The study included beneficiaries who had type 2 diabetes, stayed at nursing homes for fewer than 90 days, and were enrolled in Medicare and/or Medicaid for at least 10 months during the study period. We used Current Procedural Terminology (CPT) codes to identify the receipt of 4 measures of diabetes care quality (ie, glycated hemoglobin tests, low-density lipoprotein cholesterol tests, nephropathy tests, eye examinations). The rates of adherence (defined by proportions of beneficiaries receiving appropriate services for each measure) were compared across different types of BHDs as identified by International Classification of Diseases, Ninth Revision, Clinical Modification diagnoses. Multivariate logistic regression was used to compare the odds of adherence among beneficiaries who had BHDs with the odds among beneficiaries who had no BHDs, while adjusting for case mix.

Results: A total of 106,174 individuals met inclusion criteria. Results from adjusted analysis showed a mixed picture of the relationships between BHDs and adherence to quality measures. While substance use disorders were associated with lower adherence to quality measures, beneficiaries with diagnoses of schizophrenia or paranoid states had higher odds for adherence to quality measures.

Conclusions: Individuals with diabetes and substance use disorders receive lower quality diabetes care. Further studies to examine the factors associated with this disparity are needed.