title: Comparative safety of atypical antipsychotics and the risk of pneumonia in the elderly.
abstract: OBJECTIVE
  Previous studies have documented increased risk of pneumonia with antipsychotic use in the elderly; however, differential risk across individual atypical antipsychotics remains unaddressed. This study examines the effect of individual atypical antipsychotics on risk of pneumonia in elderly patients.
  
  
  METHODS
  This retrospective cohort study was conducted using a large claims database. The study population included new users of atypical antipsychotics (≥65 years). The multiple propensity-score adjusted survival model was used to examine risk of pneumonia within a 1-year follow-up period.
  
  
  RESULTS
  A total of 92 234 patients newly prescribed atypical antipsychotic medication were identified. Of these, 41 780 (45.30%) were quetiapine users, 31 048 (33.66%) risperidone users, 11 375 (12.33%) olanzapine users, 6790 (7.36%) aripiprazole users, and 1241 (1.35%) ziprasidone users. Within the 1-year follow-up period, 12 411 (13.46%) patients taking atypical antipsychotics had a diagnosis of pneumonia. The multiple propensity-score-adjusted survival model revealed increased risk of pneumonia with the use of risperidone (hazard ratios (HR) 1.14, 95%CI 1.10-1.18) and olanzapine (HR 1.10, 95%CI 1.04-1.16) compared with the use of quetiapine.
  
  
  CONCLUSIONS
  This large population-based study suggests that use of risperidone and olanzapine increases risk of pneumonia compared with use of quetiapine in elderly patients. This study provides new information on the comparative risk of pneumonia associated with different atypical antipsychotics in the elderly to support optimal treatment decisions.
authors.affiliation: Quintiles, Inc., Cambridge, MA, USA.
authors.forename: Sandhya
authors.initials: S
authors.lastname: Mehta
authors.affiliation: Inovalon, Inc., Bowie, MD, USA.
authors.forename: Zulkarnain
authors.initials: Z
authors.lastname: Pulungan
authors.affiliation: Inovalon, Inc., Bowie, MD, USA.
authors.forename: Barton T
authors.initials: BT
authors.lastname: Jones
authors.affiliation: Inovalon, Inc., Bowie, MD, USA.
authors.forename: Christie
authors.initials: C
authors.lastname: Teigland
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014150:Antipsychotic Agents / Q000009:adverse effects*; D015331:Cohort Studies; D005260:Female; D006299:Health Services for the Aged; D006801:Humans; D007345:Insurance Claim Review; D008297:Male; D011014:Pneumonia / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D015995:Prevalence; D012189:Retrospective Studies; D018570:Risk Assessment; D016019:Survival Analysis; D014481:United States / Q000453:epidemiology
chemical_list: D014150:Antipsychotic Agents
keywords: atypical antipsychotics; comparative; elderly; multiple propensity scores; pharmacoepidemiology; pneumonia; risk; safety; second generation