Comparative effectiveness of long-acting injectable antipsychotics in a large naturalistic cohort across two European centres: Findings from the long-acting injectable antipsychotics collaborative (LAICO) study.

We aimed to evaluate and compare the use of the paliperidone palmitate-1 and 3-month (PP1M, PP3M), aripiprazole 1-month (A1M) and risperidone-LAI (RLAI) LAIs, using the following clinical outcomes: (1) the number of hospital admissions, (2) the number of hospital bed days, and (3) the use of concomitant treatments, including benzodiazepines, oral antipsychotics, and biperiden. For that purpose, we designed a cross-sectional study, from 2015 to 2021, based on non-institutionalized population accessing care from mental health services in Spain and UK who were prescribed with LAIs during 1 year. A total of 993 patients using a LAI were included. PP1M and PP3M LAIs were associated with a decreased risk of being prescribed benzodiazepines (OR ​= ​0.35, 95%CI ​= ​0.16–0.80, p ​= ​0.012; OR ​= ​0.16, 95%CI ​= ​0.07–0.38, p ​= ​0.001, respectively) and oral antipsychotics (OR ​= ​0.23, 95%CI ​= ​0.09–0.54, p ​= ​0.001; OR ​= ​0.28, 95%CI ​= ​0.11–0.67, p ​= ​0.005, respectively) compared with RLAI. A1M was also associated with a decreased risk (OR ​= ​0.29, 95%CI ​= ​0.12–0.69, p ​= ​0.005) of antipsychotic prescription compared with RLAI. Moreover, PP1M and PP3M groups were treated with lower diazepam equivalents doses compared to the A1M (p ​= ​0.021, p ​= ​0.026) and RLAI groups (p ​= ​0.036, p ​= ​0.039). Finally, PP3M was associated with lower hospital admissions and bed days compared with A1M (p ​= ​0.001; p ​= ​0.001) and RLAI (p ​= ​0.018; p ​= ​0.001). In conclusion, paliperidone LAIs had a more favourable impact on overall bed usage compared to A1M and RLAI. Furthermore, paliperidone LAIs and A1M lowered the use of concomitant psychiatric medication versus the biweekly LAIs while differences in combination and augmentation practices between cohorts are also highlighted. Our findings could be useful for clinicians and their practice.