Real-world effectiveness of long-acting injections for reducing recurrent hospitalizations in patients with schizophrenia

Background The comparative effectiveness of antipsychotic long-acting injections (LAIs) and oral medication is not clear due to various methodological problems. Methods To compare the effectiveness of LAIs and oral antipsychotics in preventing readmission in patients with schizophrenia, we performed a within-subject analysis of data collected from 75,274 patients hospitalized with schizophrenia over a 10-year period (2008-2017). Readmission rates were compared according to medication status (non-medication, oral medication alone, and LAI medication). Each admission episodes were compared according to medication status before admission. Results Total 132,028 episodes of admission were analyzed. During 255,664 person-years of total observation, 101,589 outcome events occurred. Comparing LAI to only oral medication, IRR was 0.71 (0.64-0.78, P < 0.001). IRR of LAI to only oral medication of first index admission was 0.74 (0.65-0.86). As hospitalization was repeated, IRR of second, third, and fourth or more index admission decreased 0.65 (0.53-0.79), 0.56 (0.43-0.76), and 0.42 (0.31-0.56), respectively. Conclusions LAI treatment reduced the readmission rate by 29% compared with oral medication in real-world settings. Moreover, LAIs reduced the readmission rate by 58% in patients with repeated admissions. The more readmissions, the greater the effect of LAIs in reducing the risk of re-hospitalization compared with oral antipsychotics.