Results: Background: To assess the impact of schizophrenia diagnosis on diabetes care.
Methods: We identified 399 adults with diabetes mellitus and schizophrenia diagnoses, and 13,745 adults with diabetes and no evidence of schizophrenia. Patients were categorized as having schizophrenia if they had one or more ICD-9 codes for schizophrenia in a 24 month period. Multivariate linear regression models were used to compare glycated hemoglobin (A1c) values in these two groups while adjusting for patient covariates including age, gender, Charlson comorbidity scores, outpatient medical visits and likelihood of an A1c test.
Results: Compared to diabetes patients without a schizophrenia diagnosis, those with schizophrenia diagnosis were significantly older (mean age 68.5 vs. 60.8 years, p <.0001), more likely to be female (54.9% vs. 47.9%, p<.006), had more medical comorbidity (28.3% vs. 15.0% with a Charlson score = 1, p<.0001), and more outpatient medical visits (8.6 vs. 6.8, p=.0002). Diabetes patients with a schizophrenia diagnosis also had lower rates of A1c testing (48% vs. 71%, p<.0001). Among those with an A1c test, unadjusted mean A1c was 7.4% in schizophrenia and 7.7% in non-schizophrenia patients (p<.02). After adjustment for age, gender, comorbidity score, and medical outpatient visits and test likelihood, those with schizophrenia had significantly lower A1c levels than those without schizophrenia (p<.005).
Conclusion: Adults with diabetes and schizophrenia diagnosis had more medical visits and fewer A1c tests but no evidence of worse glycemic control than adults with diabetes and no schizophrenia diagnosis.