title: Initial recovery trajectories among patients with hip fracture: a conceptual approach to exploring comparative effectiveness in postacute care.
abstract: OBJECTIVE
  To assess whether clusters of patients with hip fracture and with distinct initial recovery trajectories (IRT) could be identified by using practice-based evidence data and to examine the validity of these data.
  
  
  METHODS
  Analysis of multisite prospective observational cohort study database.
  
  
  METHODS
  Eighteen skilled nursing and inpatient rehabilitation facilities.
  
  
  METHODS
  Patients with hip fractures (N = 226) treated with joint replacement and admitted to skilled nursing or inpatient rehabilitation facilities, subset (n = 85), with telephone follow-up results approximately 8 months after rehabilitation discharge. Patients' ages were 76.8 ± 11.4 years; the majority were women (78%) and white (87%).
  
  
  METHODS
  Measurements included medical severity by using the Comprehensive Severity Index and functional levels by using Functional Independence Measure (FIM). The IRT was calculated for each patient as the rate of change in function from the time of surgery to rehabilitation admission. We used cluster analysis to partition patients into subsets that shared common IRT scores. Validity was explored by comparing subgroups across patient characteristics and treatment patterns. Significance was defined as P ≤ .05.
  
  
  METHODS
  IRT grouping, Comprehensive Severity Index, FIM, discharge location, living location at follow-up.
  
  
  RESULTS
  We identified 3 patient clusters with differentiated IRT scores: group 1: 4.96 ± 2.45 (range, 0.4-8.6) FIM point change per day; group 2: 12.42 ± 2.51 (range, 8.9-17.0); group 3: 26.80 ± 13.78 (range, 17.5-70.0). Clinical group validation was established from statistically different Comprehensive Severity Index scores on admission; FIM scores at admission, discharge, and follow-up; and discharge and 8-month living settings. Calculation of IRT recovery curves by using FIM scores and associated time in days through logarithmic regression curves confirmed each group's IRT remained distinct through rehabilitation and follow-up.
  
  
  CONCLUSIONS
  The IRT concept appears to be valid in patients with hip fracture who were treated with hip arthroplasty, and may assist in evaluating and comparing the effectiveness of postacute rehabilitation services.
authors.affiliation: Nursing Research and Development, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Suite 2021, Los Angeles, CA 90048, USA. harriet.aronow@cshs.org
authors.forename: Harriet U
authors.initials: HU
authors.lastname: Aronow
authors.forename: Phoebe
authors.initials: P
authors.lastname: Sharkey
authors.forename: Hilary C
authors.initials: HC
authors.lastname: Siebens
authors.forename: Susan D
authors.initials: SD
authors.lastname: Horn
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Smout
authors.forename: Gerben
authors.initials: G
authors.lastname: DeJong
authors.forename: Michael C
authors.initials: MC
authors.lastname: Munin
authors.forename: Craig S
authors.initials: CS
authors.lastname: Radnay
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000534:rehabilitation; D005260:Female; D005500:Follow-Up Studies; D006620:Hip Fractures / Q000503:physiopathology / Q000534:rehabilitation* / Q000601:surgery; D006621:Hip Joint / Q000502:physiology*; D006801:Humans; D007902:Length of Stay / Q000639:trends; D008297:Male; D010351:Patient Discharge / Q000639:trends; D011446:Prospective Studies; D020127:Recovery of Function; D012047:Rehabilitation Centers / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D012866:Skilled Nursing Facilities / Q000706:statistics & numerical data*; D016896:Treatment Outcome