title: Is the Hierarchy of Loss in Functional Ability Evident in Midlife? Findings from a British Birth Cohort.
abstract: Difficulties performing a range of physical tasks of daily living have been shown to develop in older populations in a typically observed sequence, known as the hierarchy of loss. Nearly all previous research has been undertaken using populations aged over 75. This study aimed to use cross-sectional and longitudinal data to test for evidence of the hierarchy of loss from midlife onwards.
  
  
  
  The prevalence of reported difficulty undertaking 16 physical tasks in the MRC National Survey of Health and Development at age 60-64 were calculated, with Mokken scaling used to confirm the hierarchical order. Logistic regression was used to calculate the odds ratios of reporting difficulty performing tasks at the bottom of the hierarchy (i.e. feeding, washing and/or toileting) at age 60-64 by reported difficulty at the top of the hierarchy (i.e. gripping, walking and/or stair climbing) at age 43.
  
  
  
  At age 60-64, tasks associated with balance, strength and co-ordination, such as climbing stairs, were the first tasks participants reported difficulty with and tasks associated with upper limb mobility, such as feeding yourself, were the last. In a fully-adjusted model, participants who reported difficulty at the top of the hierarchy at age 43 were 2.85 (95% CI: 1.45-5.60) times more likely to report difficulty with tasks at the bottom of the hierarchy at age 60-64.
  
  
  
  This study presents evidence of the hierarchy of loss in a younger population than previously observed suggesting that targeted interventions to prevent functional decline should not be delayed until old age.
authors.affiliation: MRC Unit for Lifelong Health and Ageing at UCL, London, United Kingdom.
authors.forename: Elizabeth G
authors.initials: EG
authors.lastname: Wloch
authors.affiliation: MRC Unit for Lifelong Health and Ageing at UCL, London, United Kingdom.
authors.forename: Diana
authors.initials: D
authors.lastname: Kuh
authors.affiliation: MRC Unit for Lifelong Health and Ageing at UCL, London, United Kingdom.
authors.forename: Rachel
authors.initials: R
authors.lastname: Cooper
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000375:Aging; D015331:Cohort Studies; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D010809:Physical Fitness; D006113:United Kingdom