title: A comparison of health expectancies over two decades in England: results of the Cognitive Function and Ageing Study I and II.
abstract: BACKGROUND
  Whether rises in life expectancy are increases in good-quality years is of profound importance worldwide, with population ageing. We investigate how various health expectancies have changed in England between 1991 and 2011, with identical study design and methods in each decade.
  
  
  METHODS
  Baseline data from the Cognitive Function and Ageing Studies in populations aged 65 years or older in three geographically defined centres in England (Cambridgeshire, Newcastle, and Nottingham) provided prevalence estimates for three health measures: self-perceived health (defined as excellent-good, fair, or poor); cognitive impairment (defined as moderate-severe, mild, or none, as assessed by Mini-Mental State Examination score); and disability in activities of daily living (defined as none, mild, or moderate-severe). Health expectancies for the three regions combined were calculated by the Sullivan method, which applies the age-specific and sex-specific prevalence of the health measure to a standard life table for the same period.
  
  
  RESULTS
  Between 1991 and 2011, gains in life expectancy at age 65 years (4·5 years for men and 3·6 years for women) were accompanied by equivalent gains in years free of any cognitive impairment (4·2 years [95% CI 4·2-4·3] for men and 4·4 years [4·3-4·5] for women) and decreased years with mild or moderate-severe cognitive impairment. Gains were also identified in years in excellent or good self-perceived health (3·8 years [95% CI 3·5-4·1] for men and 3·1 years [2·7-3·4] for women). Gains in disability-free years were much smaller than those in excellent-good self-perceived health or those free from cognitive impairment, especially for women (0·5 years [0·2-0·9] compared with 2·6 years [2·3-2·9] for men), mostly because of increased mild disability.
  
  
  CONCLUSIONS
  During the past two decades in England, we report an absolute compression (ie, reduction) of cognitive impairment, a relative compression of self-perceived health (ie, proportion of life spent healthy is increasing), and dynamic equilibrium of disability (ie, less severe disability is increasing but more severe disability is not). Reasons for these patterns are unknown but might include increasing obesity during previous decades. Our findings have wide-ranging implications for health services and for extension of working life.
  
  
  BACKGROUND
  UK Medical Research Council.
authors.affiliation: Institute of Health and Society, Faculty of Medicine, Newcastle University, Newcastle, UK; Newcastle University Institute for Ageing, Newcastle University, Newcastle, UK. Electronic address: carol.jagger@newcastle.ac.uk.
authors.forename: Carol
authors.initials: C
authors.lastname: Jagger
authors.affiliation: Institute of Health and Society, Faculty of Medicine, Newcastle University, Newcastle, UK; Newcastle University Institute for Ageing, Newcastle University, Newcastle, UK; Medical Research Council (MRC) Biostatistics Unit, Cambridge Institute of Public Health, Cambridge, UK.
authors.forename: Fiona E
authors.initials: FE
authors.lastname: Matthews
authors.affiliation: Institute of Health and Society, Faculty of Medicine, Newcastle University, Newcastle, UK; Newcastle University Institute for Ageing, Newcastle University, Newcastle, UK.
authors.forename: Pia
authors.initials: P
authors.lastname: Wohland
authors.affiliation: Institute of Health and Society, Faculty of Medicine, Newcastle University, Newcastle, UK.
authors.forename: Tony
authors.initials: T
authors.lastname: Fouweather
authors.affiliation: Institute of Health and Society, Faculty of Medicine, Newcastle University, Newcastle, UK; Newcastle University Institute for Ageing, Newcastle University, Newcastle, UK.
authors.forename: Blossom C M
authors.initials: BC
authors.lastname: Stephan
authors.affiliation: Institute of Health and Society, Faculty of Medicine, Newcastle University, Newcastle, UK.
authors.forename: Louise
authors.initials: L
authors.lastname: Robinson
authors.affiliation: School of Health Sciences, University of East Anglia, Norwich, UK.
authors.forename: Antony
authors.initials: A
authors.lastname: Arthur
authors.affiliation: Department of Public Health and Primary Care, Cambridge Institute of Public Health, Cambridge University, Cambridge, UK.
authors.forename: Carol
authors.initials: C
authors.lastname: Brayne
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D003071:Cognition; D003072:Cognition Disorders / Q000453:epidemiology*; D004185:Disability Evaluation; D006233:Persons with Disabilities / Q000706:statistics & numerical data; D004739:England / Q000453:epidemiology; D005260:Female; D015577:Geriatric Assessment / Q000379:methods; D006304:Health Status; D006305:Health Status Indicators; D006801:Humans; D008017:Life Expectancy / Q000639:trends*; D008297:Male; D015995:Prevalence