OBJECTIVES: This study compared treatment patterns and Medicaid spending between schizophrenia patients with cardiovascular disease (CVD), diabetes, hypertension (HTN), or obesity initiated on once-monthly paliperidone palmitate (PP1M) or an oral atypical antipsychotic (OAA).

METHODS: Medicaid data from five states (09/2008-03/2015) identified adults with schizophrenia initiated on PP1M or an OAA (index date). Patients were grouped based on ≥1 diagnosis for CVD, diabetes, HTN, or obesity during the 12 months pre-index. Outcomes (assessed during the 12 months post-index) were compared using inverse probability of treatment weighting. Treatment patterns (AP polypharmacy as well as adherence [proportion of days covered {PDC}≥80%] and persistence [no gap≥60 days] to the index AP) were compared using chi-squared tests. Medical and pre-rebate pharmacy costs were compared using linear regression with a non-parametric bootstrap procedure to compute p-values.

RESULTS: The following groups were identified: CVD (N[PP1M]=230; N[OAA]=4,071), diabetes (N[PP1M]=420; N[OAA]=5,349), HTN (N[PP1M]=655; N[OAA]=8,974), and obesity (N[PP1M]=194; N[OAA]=2,319). PP1M patients were less likely to have AP polypharmacy (eg CVD: 21% vs 28%; p<0.001) versus OAA patients. Relative to OAA patients, adherence was more likely in PP1M patients with CVD or obesity (eg CVD: 29% vs 22%; p<0.001), similar for HTN patients, and less likely for diabetes patients (22% vs 24%; p=0.031). Across all comorbidities, PP1M patients were more likely to be persistent (eg CVD: 50% vs 27%; p<0.001). There was no significant difference in total costs between PP1M and OAA patients for any comorbidity. PP1M patients with diabetes, HTN, or obesity had higher pre-rebate pharmacy costs which were offset by lower medical costs (all p<0.05).

CONCLUSIONS: Within comorbid populations (CVD, diabetes, HTN, obesity) with schizophrenia, PP1M was associated with less AP polypharmacy and more persistence to therapy compared to OAA. Total healthcare costs were not significantly different between PP1M and OAA, as medical cost savings offset higher pharmacy costs.