title: A systematic review and meta-analysis of the effect of depot antipsychotic frequency on compliance and outcome.
abstract: BACKGROUND
  Depot antipsychotics are commonly used to improve adherence and clinical outcomes such as relapse and readmission. Dosing regimens vary but are commonly two- and four-weekly. To date, the effect of administration at two-weekly or four-weekly intervals on outcome has not been examined in a meta-analysis.
  
  
  OBJECTIVE
  A systematic review and meta-analysis on whether the frequency of depot antipsychotic administration (e.g., two- vs four-weekly) makes any difference to compliance and outcome.
  
  
  METHODS
  A systematic search of Medline, EMBASE and PsycInfo for RCTs that compared the frequency of depot administration (e.g., two- vs four-weekly) for an equivalent dose. Outcomes were compliance, psychiatric symptomatology, quality of life, adverse drug reactions (ADRs), patient preference, admission rates, bed-days and costs.
  
  
  RESULTS
  Seven studies from eight papers (n=3994) were found covering olanzapine, paliperidone, risperidone, haloperidol and fluphenazine enanthate/decanoate with follow-up of up to one year. Meta-analyses were possible for psychotic symptoms and ADRs. There were no differences in psychotic symptoms or quality of life between two- and four-weekly doses. Health service use was not reported. For ADRs, the only significant difference detected was that two-weekly injections were less likely to lead to site pain (RR 0.16, 95% CI 0.07-0.38; 2 studies n=1667). There were no differences in other ADRs.
  
  
  CONCLUSIONS
  There were surprisingly little data on the effect of dosing frequency for an equivalent dose on clinical outcomes. There is a need for long-term studies of a wide range of outcomes including cost-effectiveness. Claims for advantages of new preparations over others require careful evaluation.
authors.affiliation: The University of Queensland School of Medicine, Qld, Australia; Metro South Health Service, Woolloongabba, Qld, Australia; Griffith Institute of Health, Griffith University, Qld, Australia. Electronic address: s.kisely@uq.edu.au.
authors.forename: Steve
authors.initials: S
authors.lastname: Kisely
authors.affiliation: School of Medicine, James Cook University, Qld, Australia.
authors.forename: Emily
authors.initials: E
authors.lastname: Sawyer
authors.affiliation: Metro South Health Service, Woolloongabba, Qld, Australia; Griffith Institute of Health, Griffith University, Qld, Australia.
authors.forename: Gail
authors.initials: G
authors.lastname: Robinson
authors.affiliation: The University of Queensland School of Medicine, Qld, Australia; Metro South Health Service, Woolloongabba, Qld, Australia.
authors.forename: Dan
authors.initials: D
authors.lastname: Siskind
mesh_terms: D014150:Antipsychotic Agents / Q000008:administration & dosage*; D004334:Drug Administration Schedule; D006801:Humans; D010349:Patient Compliance; D016896:Treatment Outcome
chemical_list: D014150:Antipsychotic Agents
keywords: Depot antipsychotic; Dosing frequency; LAI; Outcomes