title: Frequency, risk factors, and prognosis of prolonged delirium in elderly patients after hip fracture surgery.
abstract: BACKGROUND
  Delirium in elderly patients after hip fracture surgery is believed to be a transient event, although it frequently lasts for more than 4 weeks.
  
  
  OBJECTIVE
  We determined the incidence, risk factors, morbidity, and mortality of prolonged delirium in elderly patients after hip fracture surgery.
  
  
  METHODS
  We evaluated 232 elderly patients (older than 65 years) (232 hips) who underwent hip fracture surgery for the development and duration of delirium and categorized them into three groups; nondelirium group, transient (≤ 4 weeks) delirium group, and prolonged (> 4 weeks) delirium group. Patients underwent a global geriatric evaluation, which included postoperative complications, mortality, and functional and mental status evaluations. The three groups were compared with respect to these variables.
  
  
  RESULTS
  Seventy patients (30.2%) had delirium develop, and among these, 14 (20%) had prolonged delirium with a total incidence of 6%. Multivariate analysis showed preinjury dementia was a risk factor of prolonged delirium. At the final followup, five (62.5%) of the eight patients who were ambulatory outdoors in the prolonged delirium group became housebound, whereas only 18 (16.4%) of the 110 patients who were ambulatory outdoors in the nondelirium group became housebound. Survival at 40 months was 81.0% (95% confidence interval, 72.6%-89.3%) in the nondelirium group and 63.6% (95% confidence interval, 35.2%-92.1%) in the prolonged delirium group.
  
  
  CONCLUSIONS
  Prolonged delirium was found to be associated with a poor functional outcome and increased mortality.
  
  
  METHODS
  Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors.forename: Kyung-Hag
authors.initials: KH
authors.lastname: Lee
authors.forename: Yong-Chan
authors.initials: YC
authors.lastname: Ha
authors.forename: Young-Kyun
authors.initials: YK
authors.lastname: Lee
authors.forename: Hyun
authors.initials: H
authors.lastname: Kang
authors.forename: Kyung-Hoi
authors.initials: KH
authors.lastname: Koo
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000401:mortality; D003693:Delirium / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality; D005260:Female; D005593:Fracture Fixation, Internal / Q000009:adverse effects* / Q000401:mortality; D006620:Hip Fractures / Q000401:mortality / Q000601:surgery*; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D056910:Republic of Korea; D018570:Risk Assessment; D012307:Risk Factors; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome