title: Baseline characteristics and hospitalizations in patients with schizophrenia receiving olanzapine long-acting injection: an interim analysis from a non-interventional, prospective observational safety study.
abstract: BACKGROUND
  Depot antipsychotics are a treatment option for medication nonadherence in patients with schizophrenia. Nonadherence can lead to increased relapse and hospitalization rates. This article reports hospitalization data before and after initiation of olanzapine long-acting injection (LAI), a depot antipsychotic.
  
  
  METHODS
  Data were assessed from an ongoing, multinational, prospective, observational post-authorisation safety study being conducted to evaluate post-injection delirium/sedation syndrome (PDSS), an adverse reaction that can occur following injection of olanzapine LAI. Eligible patients were aged ≥18 years, diagnosed with schizophrenia, were prescribed olanzapine LAI, and lived outside the United States. Psychiatric hospitalization and medication data were collected retrospectively for the 6-month period before study entry and prospectively throughout the study. Paired t-tests and McNemar's tests were used to assess changes in hospitalization incidence and duration. Stepwise Cox proportional hazards models assessed factors associated with hospitalizations. Analyses were based on data from the first 3 years of the continuously enrolling study (N = 668).
  
  
  RESULTS
  The average duration of olanzapine LAI exposure for all patients was 0.768 years. Of the 529 patients who received at least 1 injection of olanzapine LAI and were not hospitalized at study entry, 8.1% had at least 1 subsequent psychiatric hospitalization with a mean duration of 2.0 days. Of the 288 patients who had a >6-month follow-up, 8.3% had at least 1 post-baseline psychiatric hospitalization with a mean duration of 2.3 days. The incidence of hospitalizations in the 6-month period after treatment was significantly lower than that in the 6-month period prior to treatment (8.3 vs 32.6%, respectively; P < 0.001). Furthermore, mean hospitalization duration decreased from 11.5 days in the 6-month period before treatment to 2.3 days in the 6-month period after treatment (P < 0.001). Psychiatric hospitalization in the prior 12 months (P < 0.0001) and recreational drug use within 24 h of baseline visit (P = 0.015) were identified as potential predictors of time to first psychiatric hospitalization after beginning to take olanzapine LAI. At the time of interim analysis, 5 PDSS events had occurred, which was too few for a full analysis of those events.
  
  
  CONCLUSIONS
  Results indicate a significant reduction in the incidence and days of hospitalization from the 6-month period before to the 6-month period after olanzapine LAI initiation, which suggests reduced relapse and hospitalization during treatment. Results should be interpreted with caution due to the observational nature of the study and use of retrospective baseline data.
authors.affiliation: Eli Lilly and Company, Indianapolis, IN, 46285, USA. jones_meghan@lilly.com.
authors.forename: Meghan E
authors.initials: ME
authors.lastname: Jones
authors.affiliation: Eli Lilly and Company, Indianapolis, IN, 46285, USA. andrews_jeffrey_scott@lilly.com.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Andrews
authors.affiliation: Eli Lilly and Company, Indianapolis, IN, 46285, USA. faries_douglas_e@lilly.com.
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Faries
authors.affiliation: Eli Lilly Canada, Inc., Toronto, ON, M1N 2E8, Canada. landry_john@lilly.com.
authors.forename: John
authors.initials: J
authors.lastname: Landry
authors.affiliation: MacroStat (China) Clinical Research Co., Ltd., Shanghai, China. jenny.xu@macrostat.com.
authors.forename: Jenny
authors.initials: J
authors.lastname: Xu
authors.affiliation: Eli Lilly and Company, Indianapolis, IN, 46285, USA. detke_holland_c@lilly.com.
authors.forename: Holland C
authors.initials: HC
authors.lastname: Detke
authors.affiliation: Lilly UK, Windlesham, Surrey, GU20 6PH, UK. chhabra-khanna_rashna@lilly.com.
authors.forename: Rashna
authors.initials: R
authors.lastname: Chhabra-Khanna
authors.affiliation: Eli Lilly and Company, Cork, Ireland. david.mcdonnell@alkermes.com.
authors.forename: David P
authors.initials: DP
authors.lastname: McDonnell
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000009:adverse effects; D001569:Benzodiazepines / Q000008:administration & dosage / Q000009:adverse effects; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000009:adverse effects; D003693:Delirium / Q000139:chemically induced* / Q000628:therapy; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives; D007273:Injections, Intramuscular; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D000077152:Olanzapine; D017063:Outcome Assessment, Health Care; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy; D055502:Secondary Prevention / Q000379:methods; D013997:Time Factors; D014481:United States
chemical_list: D014150:Antipsychotic Agents; D003692:Delayed-Action Preparations; D006993:Hypnotics and Sedatives; D001569:Benzodiazepines; D000077152:Olanzapine