Evaluating the Cost and Clinical Effectiveness of Long-acting, Injectable Aripiprazole and Paliperidone Palmitate Once a Month in a Real-world Setting

Background: Antipsychotics are an effective treatment option for patients with schizophrenia and several long-acting injectables (LAIs), including risperidone, olanzapine, paliperidone, and aripiprazole are available in the UK. Treatment adherence is an issue in severe mental illness and LAIs have been hypothesized to offer clinical advantages over their oral equivalents. However, meta-analyses of randomized clinical trials and mirror-image studies have yielded equivocal results and have focused on economic rather than clinical outcomes.

Objective: This study evaluated routinely collected data to ascertain cost-effectiveness and clinical outcomes of two LAIs, aripiprazole and paliperidone palmitate once a month. Clinical effectiveness was assessed using the Health of the Nation Outcome Scale (HoNOS) scores.

Materials And Methods: A 1-year mirror image observational study of patients cared for by North Staffordshire Combined Healthcare Trust who received either the LAIs aripiprazole or paliperidone once a month from 2011 until the end of the study in 2016. The primary outcome was the effectiveness of the LAIs using a mirror-image design with HoNOS scores and bed use as the main outcomes.

Results: A total of 30 patients received aripiprazole and 84 received paliperidone once a month during the study period. A significant reduction in bed use was accompanied by clinical improvements, as measured by the HoNOS for both study drugs (aripiprazole: 13.4 before vs 8.7 after [=0.001]; paliperidone: 15.8 before vs 12.9 after [=0.02]). Analysis of several metabolic markers showed mean values within the normal range but the mean prolactin level in patients treated with paliperidone once a month was elevated.

Conclusion: The LAIs aripiprazole and paliperidone once a month are associated with clinical improvement and reduced bed use. Routine data gathering using, for example, HoNOS will offer the opportunity to provide additional insights into the clinical and cost benefits associated with LAIs and other interventions in the treatment of schizophrenia.