Cost-effectiveness analysis of treatment strategies initiating with second-generation antipsychotic long-acting injectables in patients with schizophrenia in the United States.

Abstract

Schizophrenia is associated with high treatment nonadherence and economic burden in the United States. Long-acting injectable (LAI) antipsychotics may improve adherence and reduce relapse risk, but comparative cost-effectiveness data of second-generation antipsychotic (SGA) LAIs in the United States remain limited. To compare the cost-effectiveness of treatment strategies initiating with 4 SGA LAIs, aripiprazole monohydrate, aripiprazole lauroxil, olanzapine pamoate, and risperidone, with the strategy initiating with monthly paliperidone palmitate in patients with schizophrenia from the US health care sector perspective. A Markov model with 90-day cycles was developed to simulate the progression of 40-year-old adults transitioning among stable treated, stable nontreated, and relapse health states and death over 5 years at a 3% discount rate. Patients transitioned to additional lines of therapy (another SGA LAI and then clozapine) after relapse or intolerance to side effects. Transition probabilities were derived from US claims-based observational studies, clinical trials, and meta-analyses. Health state utilities and disutilities due to extrapyramidal symptoms, weight gain, and diabetes from published literature were applied to age-adjusted utility of the US population. Compared with the treatment strategy initiating with paliperidone (3.22 quality-adjusted life-years [QALYs]), treatment strategies initiating with the other SGA LAIs generated slightly lower to similar QALYs. Strategies initiating with aripiprazole monohydrate and risperidone were dominated by the paliperidone-initiating strategy. Strategies initiating with aripiprazole lauroxil and olanzapine resulted in lower total health care costs but lower QALYs, with incremental cost-effectiveness ratios of $242,477 and $2,887, respectively. Sensitivity analysis confirmed the robustness of these findings, with LAI drug costs and relapse probabilities being the most influential parameters. Over a 5-year horizon, the treatment strategy initiating with paliperidone emerged as a favorable LAI option, providing the highest QALY gains at comparable or lower costs than the other LAI-initiating strategies.