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,  < 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.