The effect of long-acting injectable antipsychotic medications compared with oral antipsychotic medications among people with schizophrenia: A systematic review and meta-analysis

Chizimuzo T.C. Okoli, Amani Kappi, Tianyi Wang, Andrew Makowski, Andrew T. Cooley

Research output: Contribution to journalReview articlepeer-review

2 Scopus citations


Long-acting injectable (LAI) antipsychotic medications may be an important modality of reducing costs, improving symptoms, and fostering quality of life outcomes for those with schizophrenia. Our objective was to systematically review and conduct a meta-analysis of the effectiveness of LAIs compared with oral antipsychotics on medication adherence, symptom remission/relapse, rehospitalization, outpatient visits, emergency department visits, healthcare costs, and social functioning. We performed a systematic search of PsycInfo, CINAHL, PubMed, and Scopus databases to examine studies meeting inclusion criteria prior to August 30th, 2020. Randomized controlled trials, retrospective studies, prospective studies among people with schizophrenia with at least 6-month follow-up data were obtained. Overall effect sizes and associated 95% confidence intervals (CI) were estimated with random-effects modeling. We found 75 articles meeting our inclusion criteria, including 341 730 individuals with schizophrenia. Systematic review results indicated that LAIs compared with orals improved medication adherence (25/29 studies), symptom remission/relapse (10/18 studies), rehospitalizations (26/49 studies), emergency department visits (9/17 studies), medical costs (11/15 studies), and social functioning (5/9 studies); however, LAIs also increased outpatient visits (7/16 studies) and pharmacy costs (10/10 studies). Meta-analytic results of studies with similar outcome measures did not find differences between LAIs and orals in respect to outcomes, except lowering emergency department visits and increasing pharmacy costs. The differences between the results of the narrative synthesis and the meta-analyses were possibly because of the low availability of studies with similar outcomes in the pooled analyses. Our overall results suggest that LAIs are at least comparable to orals in supporting important healthcare outcomes for those with schizophrenia. These findings support clinical practice in encouraging providers to prescribe LAIs when indicated.

Original languageEnglish
Pages (from-to)469-535
Number of pages67
JournalInternational Journal of Mental Health Nursing
Issue number3
StatePublished - Jun 2022

Bibliographical note

Funding Information:
The research reported in this publication was supported, in part, by the Cabinet for Health and Family Services, Department for Medicaid Services under Agreement titled “Assessing the Impact of Long Acting Injectables on Psychiatric Treatment Outcomes among Medicaid Beneficiaries.”

Publisher Copyright:
© 2021 John Wiley & Sons Australia, Ltd.


  • adherence
  • antipsychotic medications
  • healthcare utilization
  • rehospitalization
  • schizophrenia
  • symptom remission

ASJC Scopus subject areas

  • Psychiatric Mental Health


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