Diabetes quality of care and outcomes: comparison of individuals with and without schizophrenia

Objective — Individuals with schizophrenia are more likely to develop diabetes than individuals without schizophrenia. The objective of this study was to determine the quality of diabetes care and diabetes-related health outcomes among individuals with and without schizophrenia.

Method — We conducted a retrospective cohort study. As of April 1, 2011, we identified all individuals with diabetes in Ontario with and without a diagnosis of schizophrenia. The main outcomes were quality of diabetes care (guideline-concordant testing for HbA1c, lipid testing, eye exams) and diabetes-related Emergency Department (ED) visits and hospitalizations between April 1, 2011 and March 31, 2013. We compared quality of care and diabetes outcomes among those with and without schizophrenia, adjusting for demographic, illness severity, and health service utilization variables.

Results — We identified 1,131,375 individuals with diabetes, among whom 25,628 (2.3%) had schizophrenia. Schizophrenia was associated with reduced likelihood of optimal diabetes care (all 3 of HbA1c, lipid testing, and eye exams) (adjusted OR (95% CI): 0.64 (0.61 – 0.67)) and increased likelihood of diabetes-related ED visits (adjusted OR (95% CI): 1.34 (1.28 – 1.41)) and hospitalizations (adjusted OR (95% CI): 1.36 (1.28 – 1.43)).

Conclusion — Individuals with diabetes and schizophrenia have lower rates of recommended testing and higher rates of diabetes-related hospital visits than those with diabetes but without schizophrenia. Research is needed to understand patient, provider, and system factors underlying these disparities and test related interventions to close the gaps in quality of care.