title: Factors influencing length of stay and mortality after first and second hip fractures:  an event modeling analysis.
abstract: OBJECTIVE
  The aim of this study was to investigate factors influencing length of stay and mortality in first and second hip fractures.
  
  
  METHODS
  This was a retrospective study with data analysis.
  
  
  METHODS
  The study was conducted at a level 1 trauma center.
  
  
  METHODS
  Six hundred and seventy-two patients treated for hip fractures (OTA 31-A, 31-B, 32-A1.1) over 30 months were split into 2 groups. 1FG: Six hundred and ten patients (90.8%) suffered a fracture for the first time. 2FG: Sixty-two patients (9.2%) had previously sustained contralateral fractures.
  
  
  METHODS
  Dynamic hip screws or cephalomedullary nails (31-A fractures); cephalomedullary nails (32-A1.1); dynamic hip screws or cannulated screws (undisplaced 31-B fractures); and hemiarthroplasty (displaced 31-B fractures) were used.
  
  
  METHODS
  Postoperative lengths of stay on trauma ward (LOS-T) on the rehabilitation unit (LOS-R) and in hospital (LOS-H) were calculated. Dates of death were recorded. Event analysis and structural equation modeling were used to assess the impact of second fractures, fracture types, age, gender, and ASA grades on these.
  
  
  RESULTS
  : The 2 groups were comparable in gender distribution, ASA grades, fracture types, LOS, and mortality at 120 days. 2FG patients were older than 1FG (mean 83.3 vs 80.2 years) with a higher proportion being discharged to institutional care (35.5% vs 18.5%). Event modeling analysis showed that LOS-T was dependent on ASA grade, whereas mortality was dependent on ASA grade, age, and gender. Second fractures were not related to the risks of increased LOS-T, LOS-R, and mortality.
  
  
  CONCLUSIONS
  Second fractures per se do not increase the risk of longer postoperative stay or higher mortality. Any observed effect on these outcomes in second fractures represents the influence of increasing age.
  
  
  METHODS
  Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Trauma and Orthopaedics, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom. sameer.khan@doctors.net.uk
authors.forename: Sameer K
authors.initials: SK
authors.lastname: Khan
authors.forename: Steven P
authors.initials: SP
authors.lastname: Rushton
authors.forename: Anis
authors.initials: A
authors.lastname: Dosani
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Gray
authors.forename: David J
authors.initials: DJ
authors.lastname: Deehan
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006620:Hip Fractures / Q000401:mortality* / Q000601:surgery*; D006801:Humans; D007902:Length of Stay; D008297:Male; D008954:Models, Biological; D012008:Recurrence; D012189:Retrospective Studies