title: Preliminary prediction model for fear-induced activity limitation after total knee arthroplasty in people 60 years and older: prospective cohort study.
abstract: OBJECTIVE
  To assess the presence of fear-induced activity limitation (FIAL) in a sample of patients 1 year after total knee arthroplasty (TKA), and to develop a preliminary prediction model to predict the risk of FIAL.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  A tertiary teaching hospital.
  
  
  METHODS
  Patients (N=72; mean age, 70±6y) undergoing primary, unilateral TKA participated.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Preoperative candidate predictors were age, sex, body mass index, previous falls history, number of comorbidities, self-report physical function, gait speed, knee range of motion, knee pain, and standing balance. Outcome measure at 1-year follow-up was the level of FIAL, measured by the Survey of Activities and Fear of Falling in the Elderly.
  
  
  RESULTS
  Thirty-one patients (41%; 95% confidence interval, .31-.55) had FIAL, of whom 15 had moderate to severe FIAL. Multivariable predictors of FIAL included preoperative habitual gait speed and velocity of postural sway in the anterior-posterior axis. A 2-variable nomogram-based prediction model was constructed, and this model showed moderately good discrimination (optimism-corrected c-index, .76) and adequate calibration.
  
  
  CONCLUSIONS
  In our sample of patients with TKA, FIAL is common, and early identification of patients at risk of FIAL would bring them into appropriate modes of preventive care. Our prediction model shows some promise in identifying patients with FIAL, but prospective validation studies are needed.
authors.affiliation: Department of Physiotherapy, Singapore General Hospital, Singapore, Singapore. puayonghao@gmail.com
authors.forename: Yong-Hao
authors.initials: YH
authors.lastname: Pua
authors.forename: Peck-Hoon
authors.initials: PH
authors.lastname: Ong
authors.forename: Amanda Yan-Ying
authors.initials: AY
authors.lastname: Lee
authors.forename: Jiajie
authors.initials: J
authors.lastname: Tan
authors.forename: Adam L
authors.initials: AL
authors.lastname: Bryant
authors.forename: Ross A
authors.initials: RA
authors.lastname: Clark
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000523:psychology*; D004185:Disability Evaluation; D005239:Fear; D005260:Female; D005684:Gait / Q000502:physiology; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D051346:Mobility Limitation; D004856:Postural Balance / Q000502:physiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology