New Study Looks At Whether People Living Longer Are Living In Good Or Poor Health

A new study published in the Lancet Public Health looked at global, regional, and national trends in the morbidity gap and contributing diseases, injuries, and risk factors.

“We wanted to answer a deceptively simple question,” study lead and corresponding author, Professor Simon I. Hay told us. “As people live longer, are those extra years being lived in good health or in poor health? For decades the hope has been that as lifespans stretch, illness would be squeezed into a short period at the very end. We set out to test whether that is actually happening, worldwide, using the most complete and consistent health data available.”

Hay is a professor in the Department of Health Metrics Sciences at the University of Washington School of Medicine and Director of Research Strategy at the Institute for Health Metrics and Evaluation. He told us that the research team had a theory of what the results would be.

“There are two long-standing and opposing ideas in this field, that longer lives would ‘compress’ illness into fewer years, or that they would instead ‘expand’ the time spent unwell,” Hay told us. “My working expectation, from watching chronic and disabling conditions rise, was that we would see expansion. What I honestly did not know was how consistent it would be from country to country.”

Hay believes the question this study is asking is one of the most important unanswered questions in population health (at scale), and it has sat unresolved for around 45 years, largely because no one had comparable data across enough countries and years to settle it. 

“It also matters enormously right now,” Hay told us. “Every aging society is planning for longer lives, and whether those years are healthy changes almost every decision, from how we fund care to how we think about work, pensions, and later life.”

For 204 countries and territories, from 1990 to 2023, the research team calculated two things: how long people live, and how long they live in good health. The distance between the two, the years spent in poor health, is what’s called the morbidity gap. The researchers then tracked how that gap changed over time and broke it down to see which diseases and which risk factors were driving it.

The researchers found that the gap grew. Globally, the years spent in poor health rose from about 8.8 to 10.7 over the period, roughly two extra years of ill health in a single generation, and the share of life spent unwell edged up to about 14.5%. 

“It widened in almost every country we looked at,” Hay told us. “Two patterns stood out: the gap is largest in the wealthiest, longest-lived nations, not the poorest; and it is driven less by the classic killers and more by conditions that disable rather than kill: back and joint pain, mental health conditions, hearing loss, and falls. Mental disorders were among the single biggest contributors.”

Though not surprised with the direction, the researchers were surprised with the details.

“I found it genuinely striking that the countries doing ‘best’ on longevity carry the biggest burden of unhealthy years,” Hay told us. “Long life turns out not to be the same thing as healthy life. And I was struck by how much of the gap comes from conditions we too often treat as secondary, mental health chief among them, rather than from the diseases that dominate the headlines.”

Hay believes the results mean we are currently adding years to life faster than we are adding health to those years, and he believes that has to change. 

“If longevity keeps rising while healthy years lag, we simply store up more time lived in poor health,” Hay told us. “The encouraging part is that a large share of the gap comes from things we can act on including mental health, which is both a leading contributor and, with the right investment in care and prevention, a very modifiable one. Health systems built mainly to prevent death now need to be rebuilt to protect health across the whole of a longer life.”