Objective
Second-generation antipsychotics increase the risk for diabetes and other metabolic conditions among people with schizophrenia. While metabolic testing is recommended to reduce this risk, low testing rates prompt concerns of negative health consequences and downstream medical costs. This study simulated the effect of increasing metabolic testing rates on 10-year prevalence rates of pre-diabetes and diabetes (diabetes conditions) and their associated healthcare costs.
Methods
A microsimulation model with a 10-year time horizon was used to quantify the impacts of policies that increase annual testing rates in a Medicaid population with schizophrenia. Data sources included California Medicaid data, National Health and Nutrition Examination Survey data, and the literature. In the model, metabolic testing increases diagnosis of diabetes conditions and diagnosis prompts prescribers to switch patients to lower-risk antipsychotics. Key inputs include observed diagnoses, prescribing rates, annual testing rates, imputed rates of undiagnosed diabetes conditions, and literature-based estimates of policy effectiveness.
Results
Relative to 2009 annual testing rates, 10-year outcomes for policies that achieve universal testing reduced exposure to higher-risk antipsychotics by 14%, time to diabetes diagnosis by 57%, and diabetes prevalence by .6%. These policies were associated with higher spending due to testing and earlier treatment.
Conclusions
Policies that promote metabolic testing provide an effective approach to improve the safety of second-generation antipsychotic prescribing in a Medicaid population with schizophrenia yet lead to additional costs at 10 years. Simulation studies are a useful source of information on the potential impacts of these policies.