title: Antipsychotic drug use and risk of pneumonia in elderly people.
abstract: OBJECTIVE
  To investigate the association between antipsychotic drug use and risk of pneumonia in elderly people.
  
  
  METHODS
  A nested case-control analysis.
  
  
  METHODS
  Data were used from the PHARMO database, which collates information from community pharmacies and hospital discharge records.
  
  
  METHODS
  A cohort of 22,944 elderly people with at least one antipsychotic prescription; 543 cases of hospital admission for pneumonia were identified. Cases were compared with four randomly selected controls matched on index date.
  
  
  METHODS
  Antipsychotic drug use in the year before the index date was classified as current, recent, or past use. No prescription for an antipsychotic in the year before the index date was classified as no use. The strength of the association between use of antipsychotics and the development of pneumonia was estimated using multivariate logistic regression analysis and expressed as odds ratios (ORs) with 95% confidence intervals (CIs).
  
  
  RESULTS
  Current use of antipsychotics was associated with an almost 60% increase in the risk of pneumonia (adjusted OR=1.6, 95% CI=1.3-2.1). The risk was highest during the first week after initiation of an antipsychotic (adjusted OR=4.5, 95% CI=2.8-7.3). Similar associations were found after exclusion of elderly people with a diagnosis of delirium. Current users of atypical agents showed a higher risk of pneumonia (adjusted OR=3.1, 95% CI=1.9-5.1) than users of conventional agents (adjusted OR=1.5, 95% CI=1.2-1.9). There was no clear dose-response relationship.
  
  
  CONCLUSIONS
  Use of antipsychotics in elderly people is associated with greater risk of pneumonia. This risk is highest shortly after the initiation of treatment, with the greatest increase in risk found for atypical antipsychotics.
authors.affiliation: Department of Geriatrics, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Wilma
authors.initials: W
authors.lastname: Knol
authors.forename: Rob J
authors.initials: RJ
authors.lastname: van Marum
authors.forename: Paul A F
authors.initials: PA
authors.lastname: Jansen
authors.forename: Patrick C
authors.initials: PC
authors.lastname: Souverein
authors.forename: Alfred F A M
authors.initials: AF
authors.lastname: Schobben
authors.forename: Antoine C G
authors.initials: AC
authors.lastname: Egberts
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000009:adverse effects*; D003680:Deglutition Disorders / Q000139:chemically induced / Q000150:complications*; D003704:Dementia / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D011307:Drug Prescriptions; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D051346:Mobility Limitation; D009426:Netherlands / Q000453:epidemiology; D016017:Odds Ratio; D011014:Pneumonia / Q000453:epidemiology / Q000209:etiology*; D012189:Retrospective Studies
chemical_list: D014150:Antipsychotic Agents