title: Determinants of physical health in frail older people: the importance of self-efficacy.
abstract: OBJECTIVE
  There is continued uncertainty regarding the strength of association between performance-based and self-report measures of physical functioning, and of their relationship to self-efficacy and health-related quality of life (HRQoL). This study assessed the inter-relationships between such measures, and the predictors of 'physical' aspects of HRQoL in frail older patients.
  
  
  METHODS
  We used statistical models to determine the predictors of 'physical' HRQoL, according to the physical component summary score and the physical functioning domain of the 36-item short form (SF-36) questionnaire.
  
  
  METHODS
  Patients were recruited from hospitals in Australia and New Zealand and followed up in their homes.
  
  
  METHODS
  Two hundred and forty-three frail older patients.
  
  
  METHODS
  Physical functioning was assessed using three performance-based measures (Timed Up and Go Test, gait speed and the Berg Balance Scale) and five self-report measures, including the modified falls self-efficacy scale, at three and six months after registration.
  
  
  RESULTS
  A moderate association (r = 0.48-0.55) was found between each of the performance-based and self-report measures, including the SF-36 physical component summary score. Multiple linear regression analyses showed that the performance-based measures and falls self-efficacy predicted 33% of the SF-36 physical component summary score. Falls self-efficacy was the single highest predictor of both the SF-36 physical component summary score and SF-36 physical functioning domain. A curvilinear relationship was found between the SF-36 physical functioning domain and two variables: falls self-efficacy and the Berg Balance Scale.
  
  
  CONCLUSIONS
  Although performance-based and self-report measures provide complementary but distinct measures of physical function, psychosocial factors such as self-efficacy have a strong influence on the HRQoL of frail older people.
authors.affiliation: School of Physiotherapy, Auckland University of Technology, New Zealand.
authors.forename: Caroline M
authors.initials: CM
authors.lastname: Stretton
authors.forename: Nancy K
authors.initials: NK
authors.lastname: Latham
authors.forename: Kristie N
authors.initials: KN
authors.lastname: Carter
authors.forename: Arier C
authors.initials: AC
authors.lastname: Lee
authors.forename: Craig S
authors.initials: CS
authors.lastname: Anderson
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D016330:Frail Elderly; D006304:Health Status; D006801:Humans; D008297:Male; D015233:Models, Statistical; D011788:Quality of Life; D020377:Self Efficacy