title: Non-steroidal anti-inflammatory drugs and the risk of a second hip fracture: a propensity-score matching study.
abstract: BACKGROUND
  Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently prescribed for elderly patients, particularly after a hip fracture. However, we are not clear about the effect of NSAIDs on the risk of a second hip fracture because of confounding factors.
  
  
  METHODS
  This was a Taiwan National Health Insurance Research Database-based study using propensity-score matching (PSM) to control for confounding. Enrollees were selected from patients with a hip fracture during 1996-2004 and followed longitudinally until December 2009. After PSM for comorbidities and bisphosphonate therapy, 94 patients with a second hip fracture were assigned to the Cases group and 461 without it to the Controls group. The target drugs are NSAIDs; paracetamol and dexamethasone are used for comparison.
  
  
  RESULTS
  The correlation between the mean daily-dose (MDD) ratios of NSAIDs and the probability values of the current statistical tests were highly negative (Pearson's r = -0.920, P = 0.003), which indicated that the higher the MDD ratios, the greater the risks of a second hip fracture. A Kaplan-Meier survival analysis showed a time-dependent trend of increasing risk of a second hip fracture in patients taking NSAIDs (P < 0.001). Moreover, patients ≥ 60 years old had a higher risk of a second hip fracture than did those <60 and taking the NSAIDs diclofenac (P = 0.016) and celecoxib (P = 0.003) and the corticosteroid dexamethasone (P = 0.018), but not those taking analgesic paracetamol (P = 0.074).
  
  
  CONCLUSIONS
  We conclude that taking NSAIDs after a fragility hip fracture dose- and time-dependently significantly increases the risk of a second hip fracture, especially in elderly patients. To lower the risk of a second hip fracture, any underlying causes for excessively using NSAIDs should be treated and thus fewer NSAIDs prescribed after a first hip fracture.
authors.affiliation: Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, Chiayi, Taiwan.|College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Po-Yao
authors.initials: PY
authors.lastname: Chuang
authors.affiliation: Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, Chiayi, Taiwan.|College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Shih-Hsun
authors.initials: SH
authors.lastname: Shen
authors.affiliation: Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, Chiayi, Taiwan.|College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Tien-Yu
authors.initials: TY
authors.lastname: Yang
authors.affiliation: Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, Chiayi, Taiwan.|College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Tsan-Wen
authors.initials: TW
authors.lastname: Huang
authors.affiliation: Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, Chiayi, Taiwan. kc2672@gmail.com.|College of Medicine, Chang Gung University, Taoyuan, Taiwan. kc2672@gmail.com.
authors.forename: Kuo-Chin
authors.initials: KC
authors.lastname: Huang
mesh_terms: D000082:Acetaminophen / Q000009:adverse effects; D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects*; D016022:Case-Control Studies; D016208:Databases, Factual; D004008:Diclofenac / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006620:Hip Fractures / Q000139:chemically induced* / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D008297:Male; D011159:Population Surveillance; D057216:Propensity Score; D012008:Recurrence; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D004008:Diclofenac; D000082:Acetaminophen
keywords: Fragility hip fracture; Non-steroidal anti-inflammatory drugs; Population-based study; Propensity-score matching; Second hip fracture