Long-acting Injectable vs. Oral Antipsychotics: Adherence, Persistence and Switching over three Years of Real-life Analysis

Background: Persistence and adherence to treatment are considered efficacy outcomes in psychiatric disorders. One of the best ways to improve these values in patients with psychiatric disorders is to prefer Long-Acting Injectable (LAI) drugs to oral AP. Objective: The objective of this study is to evaluate adherence, persistence and switching of antipsychotics and compare in real life long-acting with oral formulations. Materials and Methods: This pharmacological, observational, retrospective and non-interventional study involved all patients of the ASL of Pescara treated in the front-line with AP in the period between January 2011 and February 2019. Adherence was measured using the ratio between the received daily dose and prescribed daily dose. Persistence to treatment with antipsychotics was calculated as the daily difference between the beginning and end of treatment. Results: We examined 840 patients treated with aripiprazole, 130 patients treated with paliperidone and 925 patients treated with risperidone. Adherence was significantly better in long-acting formulations with values of 0.89 (aripiprazole) and 0.82 (paliperidone and risperidone) than in oral formulations with values of 0.78, 0.70 and 0.58, respectively (p> 0.999, p= 0.0091, p=< 0.0001). Threeyear persistence curves relating to three study drugs did not show a statistically significant difference (p = 0.3314). Persistence curves based on formulation have not shown a statistically significant difference (p= 0, 4658, p=0, 4794, p=0, 2199 for ariprazolo, paliperidone and risperidone, respectively). 7% of patients were treated with aripiprazole, 12% of patients were treated with risperidone and 28% of patients were treated with paliperidone switched therapy. Conclusion: In all the drugs of present study, adherence values were better in LAI than in OA, whereas no statistically significant difference was found in persistence values.