title: Testing an integral conceptual model of frailty.
abstract: OBJECTIVE
  This paper is a report of a study conducted to test three hypotheses derived from an integral conceptual model of frailty.
  
  
  BACKGROUND
  The integral model of frailty describes the pathway from life-course determinants to frailty to adverse outcomes. The model assumes that life-course determinants and the three domains of frailty (physical, psychological, social) affect adverse outcomes, the effect of disease(s) on adverse outcomes is mediated by frailty, and the effect of frailty on adverse outcomes depends on the life-course determinants.
  
  
  METHODS
  In June 2008 a questionnaire was sent to a sample of community-dwelling people, aged 75 years and older (n = 213). Life-course determinants and frailty were assessed using the Tilburg frailty indicator. Adverse outcomes were measured using the Groningen activity restriction scale, the WHOQOL-BREF and questions regarding healthcare utilization. The effect of seven self-reported chronic diseases was examined.
  
  
  RESULTS
  Life-course determinants, chronic disease(s), and frailty together explain a moderate to large part of the variance of the seven continuous adverse outcomes (26-57%). All these predictors together explained a significant part of each of the five dichotomous adverse outcomes. The effect of chronic disease(s) on all 12 adverse outcomes was mediated at least partly by frailty. The effect of frailty domains on adverse outcomes did not depend on life-course determinants.
  
  
  CONCLUSIONS
  Our finding that the adverse outcomes are differently and uniquely affected by the three domains of frailty (physical, psychological, social), and life-course determinants and disease(s), emphasizes the importance of an integral conceptual model of frailty.
authors.affiliation: Rotterdam University of Applied Sciences, Rotterdam, The Netherlands. gobrj@hr.nl
authors.forename: Robbert J
authors.initials: RJ
authors.lastname: Gobbens
authors.forename: Marcel A
authors.initials: MA
authors.lastname: van Assen
authors.forename: Katrien G
authors.initials: KG
authors.lastname: Luijkx
authors.forename: Jos M
authors.initials: JM
authors.lastname: Schols
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D005260:Female; D016330:Frail Elderly / Q000523:psychology* / Q000706:statistics & numerical data*; D015577:Geriatric Assessment / Q000706:statistics & numerical data*; D006304:Health Status; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008954:Models, Biological; D008960:Models, Psychological; D009426:Netherlands; D011788:Quality of Life; D012306:Risk; D011795:Surveys and Questionnaires