Existing evidence on clinical and economic effectiveness of one long-acting injectable antipsychotic (LAI) versus another in successful management of schizophrenia is scarce. The study was conducted to compare all-cause inpatient healthcare utilization and associated costs among Medicaid patients with schizophrenia who initiated LAIs.
This retrospective cohort analysis used the Truven Health Analytics MarketScan® Medicaid claims database. Schizophrenia patients >18 years with at least one claim for one of the following LAI were identified between 1 January 2013 and 30 June 2014 (identification period): aripiprazole, fluphenazine, haloperidol, paliperidone palmitate, and risperidone. The first day of initiating an LAI was considered the index date. Patients were followed for 1 year from index date. Logistic and general linear regression models were used to estimate risk of inpatient hospitalization and associated costs during follow up.
Of the identified Medicaid patients with schizophrenia, 1,672 (36.7 percent) initiated an LAI: 44.0 percent received paliperidone, 26.4 percent haloperidol, 13.8 percent risperidone, 9.2 percent aripiprazole, and 6.6 percent fluphenazine. With the aripiprazole cohort as the reference group, the odds of having any inpatient hospitalizations were significantly higher in haloperidol [Odds Ratio, OR (95 percent Confidence Interval, CI): 1.51 (1.05 - 2.16)] and risperidone [OR (95 percent CI): 1.58 (1.07 - 2.33)] cohorts. Fluphenazine and paliperidone palmitate cohorts also had higher risk of having any inpatient hospitalizations compared with aripiprazole, but the differences were not statistically significant (p>.05). Among LAI initiators with any inpatient hospitalizations, the adjusted mean inpatient costs were lowest in the aripiprazole cohort (USD25,616), followed by haloperidol (USD30,811), paliperidone (USD30,833), risperidone (USD31,584), and fluphenazine (USD37,338), although differences were not statistically significant.
Our study findings highlight the value of aripiprazole in reducing inpatient hospitalizations and associated costs among patients with schizophrenia. However, our study is limited as our results are reflective of a multi-state Medicaid population. Future studies are warranted to confirm the results in non-Medicaid patient populations.