title: Retrospective population cohort study on hip fracture risk associated with zolpidem medication.
abstract: OBJECTIVE
  Few studies have evaluated the hip fracture risk for zolpidem users. We assessed the risk for subjects taking zolpidem.
  
  
  METHODS
  Population-based retrospective cohort study using claims data of a universal insurance system.
  
  
  METHODS
  We identified 6,978 patients newly prescribed for zolpidem in 2000-2001 age 18 y and older, and 27,848 nonusers frequency matched with sex, age, and date visiting a clinic.
  
  
  RESULTS
  Both cohorts were followed up to the end of 2008 to measure the hip fracture incidence and risk, which considered factors such as sex, age, occupation, days of drug use, and osteoporosis status. The zolpidem users had a 2.23-fold higher hip fracture incidence than nonusers (3.10 versus 1.39 per 1,000 person-y). The risk increased with age for both cohorts. The elderly users had a 21-fold higher incidence than the younger users, or twofold higher than the elderly nonusers. Among 33 patients (20.4%) with hip fracture occurring during presumed medication days, which was accountable for an incidence of 1,083.0 per 1,000 person-y. Those taking the medicine for 8 days or longer had a moderately higher fracture rate than those taking it for less days (6.02 versus 4.48 per 100 person-times) with a ratio of 1.34 (95% confidence interval 0.42-4.56). Subjects with blue collar occupations were at a higher fracture risk.
  
  
  CONCLUSIONS
  The hip fracture risk of zolpidem users is higher than that of nonusers. Fracture prevention awareness should be disseminated to the users.
authors.affiliation: Department of Public Health, China Medical University, Taichung, Taiwan ; Department of Epidemiology, University of Texas School of Public Health, Houston, TX.
authors.forename: Fang-Yu
authors.initials: FY
authors.lastname: Lin
authors.affiliation: Institute of Epidemiology and Preventive Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Pei-Chun
authors.initials: PC
authors.lastname: Chen
authors.affiliation: Department of Psychiatry, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Chun Hui
authors.initials: CH
authors.lastname: Liao
authors.affiliation: Department of Pharmacy, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Yow-Wen
authors.initials: YW
authors.lastname: Hsieh
authors.affiliation: Department of Public Health, China Medical University, Taichung, Taiwan.
authors.forename: Fung-Chang
authors.initials: FC
authors.lastname: Sung
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006620:Hip Fractures / Q000139:chemically induced* / Q000150:complications / Q000453:epidemiology*; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000009:adverse effects; D015994:Incidence; D007344:Insurance Claim Reporting; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000150:complications / Q000453:epidemiology; D011725:Pyridines / Q000008:administration & dosage / Q000009:adverse effects*; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D055815:Young Adult; D000077334:Zolpidem
chemical_list: D006993:Hypnotics and Sedatives; D011725:Pyridines; D000077334:Zolpidem
keywords: Hip fracture; hypnotics; osteoporosis; retrospective cohort study; zolpidem