title: A comparison of risperidone and haloperidol for the risk of ischemic stroke in the elderly: a propensity score-matched cohort analysis.
abstract: OBJECTIVE
  With an increase in antipsychotic use in the elderly, the safety profile of antipsychotics has been emphasized. Strong concerns have been raised about whether the risk of ischemic stroke differs between risperidone and haloperidol. This study compared the risk of ischemic stroke between elderly patients taking risperidone and haloperidol.
  
  
  METHODS
  We conducted a retrospective cohort study using the Korea Health Insurance Review and Assessment Service database, applying a propensity-matched analysis. The cohort consisted of elderly patients who were newly prescribed haloperidol or risperidone between January 1, 2006 and December 31, 2009. Patients with prior cerebrovascular diseases (ICD-10, I60-I69), transient ischemic attack (ICD-10, G45), or cerebral tumors (ICD-10, C31) during 365 days prior to the initiation date were excluded. The study subjects were selected by propensity score matching. The outcome was defined as the first hospitalization for ischemic stroke (ICD-10, I63). Cox regression models were used to estimate the hazard ratio (HR) and 95% confidence intervals (95% CI) for ischemic stroke with haloperidol compared with risperidone use.
  
  
  RESULTS
  A total of 14,103 patients were included in the propensity-matched cohort for each drug. Overall, the incidence rate was higher for haloperidol users compared to the risperidone users (6.43 per 1000 person-years vs. 2.88 per 1000 person-years). A substantially increased risk was observed in haloperidol users (adjusted HR = 2.02, 95% CI, 1.12-3.62).
  
  
  CONCLUSIONS
  The evidence showed that haloperidol should be prescribed in the elderly with caution.
authors.affiliation: Office of Drug Utilization Review, Korea Institute of Drug Safety and Risk Management, Anyang-si, Gyeonggi-do, Korea.
authors.forename: Ju-Young
authors.initials: JY
authors.lastname: Shin
authors.affiliation: Medical Research Collaborating Center, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Nam-Kyong
authors.initials: NK
authors.lastname: Choi
authors.affiliation: Medical Research Collaborating Center, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Joongyub
authors.initials: J
authors.lastname: Lee
authors.affiliation: Office of Drug Utilization Review, Korea Institute of Drug Safety and Risk Management, Anyang-si, Gyeonggi-do, Korea.
authors.forename: Mi-Ju
authors.initials: MJ
authors.lastname: Park
authors.affiliation: Office of Drug Utilization Review, Korea Institute of Drug Safety and Risk Management, Anyang-si, Gyeonggi-do, Korea.
authors.forename: Shin Haeng
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Office of Drug Utilization Review, Korea Institute of Drug Safety and Risk Management, Anyang-si, Gyeonggi-do, Korea Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Korea bjpark@snu.ac.kr.
authors.forename: Byung-Joo
authors.initials: BJ
authors.lastname: Park
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014150:Antipsychotic Agents / Q000009:adverse effects*; D002545:Brain Ischemia / Q000139:chemically induced* / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D006220:Haloperidol / Q000009:adverse effects*; D006801:Humans; D008297:Male; D009313:National Health Programs / Q000706:statistics & numerical data; D057216:Propensity Score; D056910:Republic of Korea / Q000453:epidemiology; D012306:Risk; D018967:Risperidone / Q000009:adverse effects*; D020521:Stroke / Q000139:chemically induced*
chemical_list: D014150:Antipsychotic Agents; D006220:Haloperidol; D018967:Risperidone
keywords: Risperidone; aged; brain ischemia; geriatrics; haloperidol; stroke