Retrospective Analysis of Diabetes Care in California Medicaid Patients with Mental Illness

Serious mental illness often is associated with an increased risk of diabetes and sub-optimal diabetes care. To examine diabetes prevalence and care among Medicaid patients from one county mental health system. Retrospective cohort study combining county records and 12 months of state Medicaid claims. Patients ages 18 to 59 receiving mental health services between November 1 and 14, 2004. Dependent variables were glycolated hemoglobin A1C (HbA1c) testing, lipid testing, and eye examinations. Psychiatric status was assessed by second generation antipsychotic prescription (SGA) and low Global Assessment of Functioning (GAF) score. Among psychiatric patients, 482 (11.8%) had diabetes. Among those with diabetes, 47.3% received annual HbA1c testing, 56.0% lipid testing, and 31.7% eye examinations. Low GAF scores were associated with lower likelihood of lipid testing (OR 0.43). SGA prescription reduced the likelihood of HbA1c testing (OR 0.58) but increased the likelihood of eye examinations (OR 2.02). Primary care visits were positively associated with HbA1c and lipid testing (ORs 5.01 and 2.21, respectively). Patients seen by a fee-for-service psychiatrist were more likely to have lipid testing (OR 2.35) and eye examinations (OR 2.03). Among Medicaid psychiatric patients, worse diabetes care was associated with SGA prescription, more serious psychiatric symptoms, and receiving psychiatric care only in public mental health clinics. Diabetes care improved when patients were seen by fee-for-service psychiatrists or primary care physicians. Further study is needed to identify methods for improving diabetes care of public mental health patients.