title: Hierarchical components of physical frailty predicted incidence of dependency in a cohort of elderly women.
abstract: OBJECTIVE
  To identify the most important predictors of early disability incidence and devise a simple score of physical frailty.
  
  
  METHODS
  A cohort of 545 high-functioning women aged 75 years and older was followed for 7 years. Every year, the self-reported loss of at least one instrumental activity of daily living was chosen as definition of disability. An extension of the logistic regression for repeated responses, the random-effect model, was used to assess the effects of baseline predictors. The regression coefficients of the final multivariate model were scaled and rounded to create a practical score.
  
  
  RESULTS
  The proportion of women reporting disability increased from 22.1% to 52.1% throughout the follow-up. In the multivariate model, increasing age, lower performances in mobility and balance tests, bad perceived health, lower muscle strength, higher body mass index, lower educational level, and lower reported physical activity were strong predictors of disability. Evaluating the predictive value of the simplified predictive score on an independent cohort gave a c-statistic equal to .71.
  
  
  CONCLUSIONS
  The use of a powerful fitting method allows to establish a hierarchy between the components of physical frailty and to provide a predictive score with substantial practical value for clinicians and public health professionals.
authors.affiliation: INSERM Unité 500, Montpellier, France. carriere@montp.inserm.fr
authors.forename: Isabelle
authors.initials: I
authors.lastname: Carrière
authors.forename: Alain
authors.initials: A
authors.lastname: Colvez
authors.forename: Francois
authors.initials: F
authors.lastname: Favier
authors.forename: Claude
authors.initials: C
authors.lastname: Jeandel
authors.forename: Hubert
authors.initials: H
authors.lastname: Blain
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000375:Aging; D015992:Body Mass Index; D004185:Disability Evaluation; D004522:Educational Status; D004812:Epidemiologic Methods; D005260:Female; D016330:Frail Elderly; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D009043:Motor Activity; D018908:Muscle Weakness; D004856:Postural Balance; D011379:Prognosis; D012647:Self-Assessment