What can we expect of health in old age?
Authors: Kenneth Rockwood
Journal: The Lancet (2015)

The longing for longevity without decrepitude is ancient. Homer tells us that to live out his days with Penelope, Odysseus rejected immortality. Later restored to family and kingdom, the gods' further favour included being able to look forward to an unenfeebled old age. So how goes our longing now? Around the world, although life expectancy is increasing for most people,1GBD 2013 Mortality and Causes of Death CollaboratorsGlobal, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013.Lancet. 2015; 385: 117-171Summary Full Text Full Text PDF PubMed Scopus (5370) Google Scholar a wholly healthy old age is elusive. In The Lancet, Carol Jagger and colleagues2Jagger C Matthews FE Wohland P et al.on behalf of the Medical Research Council Cognitive Function and Ageing CollaborationA comparison of health expectancies over two decades in England: results of the Cognitive Function and Ageing Study I and II.Lancet. 2015; (published online Dec 8.)http://dx.doi.org/10.1016/S0140-6736(15)00947-2PubMed Google Scholar make clear that whether we reckon the ancient longing to be realised depends on how we measure health, and on which perspective we have. The authors compared the results from two rounds of the Cognitive Function and Ageing Study, done in England in 1991 and 2011. Health expectancy was measured in three ways: self-perceived health, life without disability, and time free from cognitive impairment. In 2011, on a background of increasing life expectancy, men spent 3·8 more years (95% CI 3·5–4·1), and women spent 3·1 more years (2·7–3·4), in good or better self-perceived health than in 1991. Similarly, fewer people rated their health as fair or poor in 2011 than in 1991, although this effect was not significant after adjustment for region, education, and deprivation. In contrast to a Swedish report3Falk H Johansson L Ostling S et al.Functional disability and ability in 75-year-olds: a comparison of two Swedish cohorts born 30 years apart.Age Ageing. 2014; 43: 636-641Crossref PubMed Scopus (46) Google Scholar of cohorts studied 30 years apart, the prevalence of disability increased. However, the pattern gives some cause for hope: men spent 1·3 more years (1·1–1·6) with mild disability, compared with 0·5 years (0·3–0·8) with moderate–severe disability; the corresponding figures for women were 2·5 years (2·2–2·8) with mild disability and 0·6 years (0·3–0·9) with moderate–severe disability. Although more time was spent with disability, moderate–severe disability decreased, so that the increase—and most of the additional time lived—was spent in a mildly disabled state. The least equivocal change was that less time was spent by women with cognitive impairment (0·7 years [0·2–1·3]), and more time spent without cognitive impairment (4·4 years [4·3–4·5]), in 2011 than in 1991. Achievement of longer life and reduced impairment is an important step towards the Homeric ideal. Especially for cognitive health, what future progress can be made is debated. The decline in cognitive impairment was not insubstantial (odds ratio [OR] 0·53 [95% CI 0·49–0·56]). Most of this decrease was accounted for by a decline in severe cognitive impairment (OR 0·49, [0·43–0·56]). This decrease is much larger than that returned so far on the massive investments in research on dementia biomarkers and hoped-for disease-modifying therapies. Those investments gamble that any positive results from proof-of-concept trials in younger (ie, from their 40s) and often otherwise well patients, especially from high-risk samples, will be relevant to older adults with many health deficits, who are the most common patients with dementia.4Song X Mitnitski A Rockwood K Age-related deficit accumulation and the risk of late-life dementia.Alzheimers Res Ther. 2014; 6: 54Crossref PubMed Scopus (76) Google Scholar Equally, whether improving overall health—lessening health deficits and their effects—would further result in reduced cognitive impairment is unknown.5Brayne C A population perspective on the IWG-2 research diagnostic criteria for Alzheimer's disease.Lancet Neurol. 2014; 13: 532-534Summary Full Text Full Text PDF PubMed Scopus (12) Google Scholar, 6Anstey KJ Dixon RA Applying a cumulative deficit model of frailty to dementia: progress and future challenges.Alzheimers Res Ther. 2014; 6: 84Crossref PubMed Scopus (15) Google Scholar Jagger and colleagues2Jagger C Matthews FE Wohland P et al.on behalf of the Medical Research Council Cognitive Function and Ageing CollaborationA comparison of health expectancies over two decades in England: results of the Cognitive Function and Ageing Study I and II.Lancet. 2015; (published online Dec 8.)http://dx.doi.org/10.1016/S0140-6736(15)00947-2PubMed Google Scholar suggest that the observed increase in mild disability might result from specific problems, notably obesity and musculoskeletal disease. Here, caution must be urged. Although understanding which illnesses contribute to disability is important, disability rates are potently related to age. As a result, the extent of overall, age-related deficit accumulation might be as important to disability rates as which illnesses people have.7Clegg A Young J Iliffe S et al.Frailty in elderly people.Lancet. 2013; 381: 752-762Summary Full Text Full Text PDF PubMed Scopus (4648) Google Scholar Health deficits are not just diseases, but can range from even minor laboratory abnormalities8Howlett SE Rockwood MR Mitnitski A Rockwood K Standard laboratory tests to identify older adults at increased risk of death.BMC Med. 2014; 12: 171Crossref PubMed Scopus (153) Google Scholar to lower than average enjoyment of life.9Steptoe A de Oliveira C Demakakos P Zaninotto P Enjoyment of life and declining physical function at older ages: a longitudinal cohort study.CMAJ. 2014; 186: E150-E156Crossref PubMed Scopus (46) Google Scholar For this reason, a broadly construed approach to improving health might pay current and future dividends. So too might a broadly construed health measure. At present, many single items vie as overall health measures—in addition to the three health measures assayed by Jagger and colleagues,2Jagger C Matthews FE Wohland P et al.on behalf of the Medical Research Council Cognitive Function and Ageing CollaborationA comparison of health expectancies over two decades in England: results of the Cognitive Function and Ageing Study I and II.Lancet. 2015; (published online Dec 8.)http://dx.doi.org/10.1016/S0140-6736(15)00947-2PubMed Google Scholar or laboratory test abnormalities or life enjoyment, are several other measures, including grip strength, drawing a clock, and the time it takes to get out of a chair and walk.9Steptoe A de Oliveira C Demakakos P Zaninotto P Enjoyment of life and declining physical function at older ages: a longitudinal cohort study.CMAJ. 2014; 186: E150-E156Crossref PubMed Scopus (46) Google Scholar Under the rubric of measuring frailty, dozens of measures now combine such items, although which should be combined and how many should be counted are disputed.7Clegg A Young J Iliffe S et al.Frailty in elderly people.Lancet. 2013; 381: 752-762Summary Full Text Full Text PDF PubMed Scopus (4648) Google Scholar Even if the "problems of old age come as a package",10Fontana L Kennedy BK Longo VD et al.Medical research: treat ageing.Nature. 2014; 511: 405-407Crossref PubMed Scopus (169) Google Scholar quantification of the package in which those problems come is a challenge for ageing research. Which view we take affects our understanding of whether progress is being made towards improved health expectancy. For example, whether women are more prone than men to disability, or whether disability is more lethal in men than in women, are two accounts of the same phenomenon.11Romero-Ortuno R Fouweather T Jagger C Cross-national disparities in sex differences in life expectancy with and without frailty.Age Ageing. 2014; 43: 222-228Crossref PubMed Scopus (57) Google Scholar That disparities in the extent of health deficits between men and women vary mostly by whether self-reported or test data are used suggests that sex and gender perspectives run deeply enough to affect mortality risk.12Theou O O'Connell MD King-Kallimanis BL et al.Measuring frailty using self-report and test-based health measures.Age Ageing. 2015; 44: 471-477Crossref PubMed Scopus (62) Google Scholar Perspective also matters. For individuals, an estimate of health expectancy provides a sense of their own chances. Policy makers must consider how health expectancy as, for example, disability prevalence, plays out against a background of an increasing number of older adults.1GBD 2013 Mortality and Causes of Death CollaboratorsGlobal, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013.Lancet. 2015; 385: 117-171Summary Full Text Full Text PDF PubMed Scopus (5370) Google Scholar Obviously, a modestly decreasing numerator will not trump a relentlessly increasing denominator. The numbers will out, with important effects for ageing societies, especially for pensions and health care in which progress is needed. An English audit of intermediate care opens boldly: "The modern general hospital is complex, expensive and has proved harmful to many [older] people, and so simpler, cheaper and safer care alternatives have been sought."13Young J Gladman JR Forsyth DR Holditch C The second national audit of intermediate care.Age Ageing. 2015; 44: 182-184Crossref PubMed Scopus (20) Google Scholar The data from the Cognitive Function and Ageing Studies do not support complacency in public policy. Jagger and colleagues2Jagger C Matthews FE Wohland P et al.on behalf of the Medical Research Council Cognitive Function and Ageing CollaborationA comparison of health expectancies over two decades in England: results of the Cognitive Function and Ageing Study I and II.Lancet. 2015; (published online Dec 8.)http://dx.doi.org/10.1016/S0140-6736(15)00947-2PubMed Google Scholar have documented important gains in health expectancies. Even so, it seems that living the unenfeebled old age promised to Odysseus will still somehow need special favour. I am the founder and a director of DGI Clinical; I have consulted for Roche and received fees for speaking from Nutricia. A comparison of health expectancies over two decades in England: results of the Cognitive Function and Ageing Study I and IIDuring 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. Full-Text PDF Open Access