title: Validity and responsiveness of the FRAIL scale in a longitudinal cohort study of older Australian women.
abstract: BACKGROUND
  To assess the validity and responsiveness of the FRAIL scale and investigate whether validity is related to the number of points used on the scale.
  
  
  METHODS
  Participants were 12,432 women born in 1921-1926 from the Australian Longitudinal Study on Women's Health; surveyed up to 6 times from 1996 to 2011. The FRAIL scale is a 5-item measure and scored as a 6-, 3-, or 2-point measure. Face validity was determined by assessing relationships with age, construct validity was determined by assessing relationships with measures of disability (activities of daily living and independent activities of daily living), and responsiveness was determined by assessing relationships with changes in self-rated health.
  
  
  RESULTS
  The proportion of women who reported their frailty as high (4 or 5 on a scale of 0 to 5) increased with age from 5.6% at age 73-78 years to 16.2% at age 85-90 years. The FRAIL scale was moderately correlated with disability, Spearman's rho ≥0.4 for activities of daily living and ≥0.5 for independent activities of daily living; slightly stronger associations were observed when it was scored as a 6-point measure. Mean change (95% confidence interval) in FRAIL 6-point scores decreased for women who reported improvements in self-rated health between successive surveys; by at least 0.08 (0.01, 0.15) and increased in those women who reported declines in self-rated health by at least 0.64 (0.57, 0.70).
  
  
  CONCLUSIONS
  The FRAIL scale is valid and responsive and is suitable for use in longitudinal studies of women in their 70s and older.
authors.affiliation: Centre for Longitudinal and Life Course Research, School of Public Health, The University of Queensland, Brisbane, Australia; Translating Research into Practice Center, Mater Research Institute, The University of Queensland, Brisbane, Australia. Electronic address: p.gardiner@uq.edu.au.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Gardiner
authors.affiliation: Centre for Longitudinal and Life Course Research, School of Public Health, The University of Queensland, Brisbane, Australia.
authors.forename: Gita D
authors.initials: GD
authors.lastname: Mishra
authors.affiliation: Centre for Longitudinal and Life Course Research, School of Public Health, The University of Queensland, Brisbane, Australia.
authors.forename: Annette J
authors.initials: AJ
authors.lastname: Dobson
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D001315:Australia; D004185:Disability Evaluation; D005260:Female; D016330:Frail Elderly; D015577:Geriatric Assessment; D006801:Humans; D008137:Longitudinal Studies; D011446:Prospective Studies
keywords: Frailty; cohort studies; longitudinal studies; responsiveness; validity