Background: the comparative effectiveness of antipsychotic long-acting injections (LAIs) and oral medication is not clear due to various methodological problems.
Objectives: to compare the effectiveness of LAIs and oral antipsychotics for preventing readmission in patients with schizophrenia.
Methods: data were obtained from the Health Insurance Review and Assessment Service (HIRA) database, which contains healthcare service claims data from patients across South Korea. We performed a within-participant analysis of data collected from 75,274 inpatient 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). Multiple episodes were analysed separately according to the number of index admission.
The study was conducted in accordance with the Helsinki Declaration. The institutional review board of the Hangang Sacred Heart Hospital approved this retrospective cohort study and waived the requirement for informed patient consent.
Results: a total of 132,028 episodes of admission were analysed. Over 255,664 person-years of total observation, 101,589 outcome events occurred. The incidence rates in the non-medication, oral medication alone, and LAI medication periods were 4.58 (95% confidence interval (CI) 4.47 to 4.70), 3.73 (95% CI 3.67 to 3.79), and 2.63 (95% CI 2.39 to 2.91), respectively. Comparing oral medication alone versus LAI, the incidence rate ratio (IRR) was 0.71 (95% CI 0.64 to 0.78, P < 0.001); the IRR for oral medication alone versus LAI for the first index admission was 0.74 (95% CI 0.65 to 0.86). As hospitalization was repeated, the IRR for the second, third, and fourth or more index admission decreased to 0.65 (95% CI 0.53 to 0.79), 0.56 (95% CI 0.43 to 0.76), and 0.42 (95% CI 0.31 to 0.56), respectively (Figure).
Conclusions: LAI treatment reduced the readmission rate by 29% compared with oral medication in real-world settings. Moreover, LAIs reduced the remission 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.
Patient or healthcare consumer involvement: our claims-based study was to investigate the effectiveness of LAIs in preventing readmissions in real-world settings in South Korea. Today, as patients and other stakeholders expect such intervention to be safe and effective and provide good value for money, the focus is increasingly on how these intervention perform in the 'real-world' and whether or not they add value to the healthcare system.