title: How many older people are frail? Using multiple imputation to investigate frailty in the population.
abstract: OBJECTIVE
  The objective of this study was to establish the extent to which frailty was associated with attrition and then compare estimates of frailty prevalence and progression estimated from the observed data to those estimated after imputation.
  
  
  METHODS
  Population-based cohort study.
  
  
  METHODS
  The Health in Men Study (HIMS) with frailty estimated at Wave 2 (2001/2004) and Wave 3 (2008) and mortality follow-up to 2010.
  
  
  METHODS
  Participants were 10,305 community-dwelling men aged 70 and older, followed for up to 10 years.
  
  
  METHODS
  Participants completed an extensive questionnaire covering functional activities and illnesses. Frailty was assessed using the FRAIL Scale and a 32-item Frailty Index.
  
  
  RESULTS
  Nonresponders at Wave 3 were more likely to have been frail at Wave 2. Imputed estimates of frailty prevalence were 8% to 10% higher than those derived from the observed data.
  
  
  CONCLUSIONS
  Epidemiological surveys may substantially underestimate the levels of frailty among older people in the general population. This selective nonresponse results in an overoptimistic view of aging populations, particularly for the very old.
authors.affiliation: Western Australian Centre for Health and Ageing, Centre for Medical Research, University of Western Australia, Crawley, Perth, Western Australia, Australia; School of Medicine and Pharmacology, University of Western Australia, Crawley, Western Australia, Australia. Electronic address: kieran.mccaul@uwa.edu.au.
authors.forename: Kieran A
authors.initials: KA
authors.lastname: McCaul
authors.affiliation: Western Australian Centre for Health and Ageing, Centre for Medical Research, University of Western Australia, Crawley, Perth, Western Australia, Australia; School of Psychiatry and Clinical Neurosciences, University of Western Australia, Crawley, Western Australia, Australia; Department of Psychiatry, Royal Perth Hospital, Perth, Western Australia, Australia.
authors.forename: Osvaldo P
authors.initials: OP
authors.lastname: Almeida
authors.affiliation: School of Surgery, University of Western Australia, Crawley, Western Australia, Australia.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Norman
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Crawley, Western Australia, Australia; Department of Endocrinology and Diabetes, Fremantle Hospital, Fremantle, Western Australia, Australia.
authors.forename: Bu B
authors.initials: BB
authors.lastname: Yeap
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Crawley, Western Australia, Australia; Department of Neurology, Royal Perth Hospital, Perth, Western Australia, Australia.
authors.forename: Graeme J
authors.initials: GJ
authors.lastname: Hankey
authors.affiliation: Vascular Biology Unit, School of Medicine, James Cook University, Townsville, Queensland, Australia.
authors.forename: Jon
authors.initials: J
authors.lastname: Golledge
authors.affiliation: Western Australian Centre for Health and Ageing, Centre for Medical Research, University of Western Australia, Crawley, Perth, Western Australia, Australia; School of Medicine and Pharmacology, University of Western Australia, Crawley, Western Australia, Australia.
authors.forename: Leon
authors.initials: L
authors.lastname: Flicker
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006233:Persons with Disabilities / Q000706:statistics & numerical data*; D018450:Disease Progression; D005500:Follow-Up Studies; D016330:Frail Elderly / Q000706:statistics & numerical data*; D015577:Geriatric Assessment; D006304:Health Status; D006801:Humans; D008297:Male; D009026:Mortality / Q000639:trends*; D011159:Population Surveillance; D018570:Risk Assessment; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric
keywords: Frailty; aged 70 and older; multiple imputation; older men