Impact of medical comorbidity on the quality of schizophrenia pharmacotherapy in a national VA sample

Background: More than half of patients with schizophrenia have comorbid chronic medical illness. During the past decade, several studies have evaluated the quality of the medical treatment of these conditions. This work examines the impact of comorbid medical conditions on the quality of schizophrenia pharmacotherapy in the Department of Veterans Affairs (VA). Methods: Data for this study came from national VA administrative databases. All VA outpatients diagnosed with schizophrenia during fiscal year 2002 were identified, and the presence of 9 chronic medical conditions was determined by ICD-9 codes. Measures of quality of schizophrenia pharmacotherapy were based on the Schizophrenia Patient Outcomes Research Team (PORT) and included the proportion of patients who received any antipsychotic medications, multiple antipsychotic medications, atypical antipsychotic medications, and dosages in compliance with PORT recommendations. Multivariate logistic regression analysis was used to determine the effects of comorbid medical illness on these measures. Results: Overall, 92.2% of the patients were prescribed an antipsychotic medication. Patients with 6 of the 9 chronic medical conditions were significantly less likely to be prescribed antipsychotic medications, and the odds of this treatment decreased with increasing medical complexity. 63.8% received doses which were within the recommended PORT guidelines. Conclusions: In a large national sample of veterans with schizophrenia, several chronic medical conditions were associated with a decreased likelihood of being prescribed an antipsychotic medication, suggesting less intensive schizophrenia treatment. Patients with medical comorbidity who were treated with antipsychotic medications were as likely to receive doses within the PORT guidelines as schizophrenic patients without medical comorbidity.