title: Risk analysis for second hip fracture in patients after hip fracture surgery: a nationwide population-based study.
abstract: OBJECTIVE
  The current treatment program for fragility hip fractures (HFx) emphasizes a combination of early surgery, rehabilitation, and tertiary prevention strategy for osteoporosis; however, the effect is unclear and little information is available on the risk factors predicting the occurrence of a second hip fracture (SHFx). The aim of this study was to explore the incidence, risk factors, and subsequent mortality of SHFx in patients after their first hip fracture surgery (HFxS).
  
  
  METHODS
  We performed a nationwide population-based longitudinal observational study using the National Health Insurance Research Database (NHIRD) of Taiwan with a logistic regression model analysis. Of 87,415 patients undergoing HFxS during the period 2004 to 2007, we identified 8027 patients who had sustained an SHFx for analyses.
  
  
  METHODS
  Data collected included patient characteristics (demographics, comorbidities, and concurrent medication use), incidence and hazard ratios of SHFx after HFxS, and subsequent age-specific mortality.
  
  
  RESULTS
  The overall incidence of SHFx was 9.18% and the age-specific mortality was increased 1.6- to 2.2-fold in patients with SHFx compared with those without after HFxS in this 7-year longitudinal study. The identified risk factors included age (AOR = 1.84, 95% CI: 1.24-2.89), female gender (AOR = 1.12, 95% CI: 1.03-2.30), obesity (AOR = 2.89, 95% CI: 1.81-3.01), diabetes (AOR = 3.85, 95% CI: 2.54-4.05), arterial hypertension (AOR = 2.45, 95% CI: 1.83-2.62), hyperlipidemia (AOR = 2.77, 95% CI: 1.27-3.19), stroke/TIA (AOR = 2.85, 95% CI: 2.20-3.23), blindness/low vision (AOR = 3.09, 95% CI: 2.54-3.73), and prolonged use of analgesics and anti-inflammatory medications (all AOR ≥ 3.05, all P values ≤.012). Bisphosphonate therapy after HFxS had a significant negative risk association with the development of an SHFx (20.8% vs 32.3%, P = .023; AOR = 2.24, 95% CI: 1.38-2.90).
  
  
  CONCLUSIONS
  We concluded that the occurrence of an SHFx and subsequent mortality in patients after HFxS is rather high. An understanding of the risk factors predicting the occurrence of an SHFx provides a valuable basis to improve health care for geriatric populations.
authors.affiliation: Department of Orthopaedics, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan.
authors.forename: Shih-Hsun
authors.initials: SH
authors.lastname: Shen
authors.affiliation: Department of Orthopaedics, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Clinical Medical Science, Chang Gung University, Taoyuan, Taiwan. Electronic address: kc2672@gmail.com.
authors.forename: Kuo-Chin
authors.initials: KC
authors.lastname: Huang
authors.affiliation: Department of Orthopaedics, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Yao-Hung
authors.initials: YH
authors.lastname: Tsai
authors.affiliation: Department of Orthopaedics, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan.
authors.forename: Tien-Yu
authors.initials: TY
authors.lastname: Yang
authors.affiliation: Department of Orthopaedics, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Mel S
authors.initials: MS
authors.lastname: Lee
authors.affiliation: College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Orthopaedics, Chang Gung Memorial Hospital, Linkou, Taiwan.
authors.forename: Steve W N
authors.initials: SW
authors.lastname: Ueng
authors.affiliation: Department of Orthopaedics, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Robert W W
authors.initials: RW
authors.lastname: Hsu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D005260:Female; D016330:Frail Elderly; D015577:Geriatric Assessment; D006620:Hip Fractures / Q000453:epidemiology* / Q000401:mortality / Q000601:surgery*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000150:complications / Q000517:prevention & control; D012008:Recurrence; D018570:Risk Assessment; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology
keywords: Second hip fracture; fracture risk; geriatrics; mortality; osteoporosis; population-based study