Life expectancy has increased worldwide, but it does not appear to be unalloyed good news. That is because the time spent in poor health has grown. The gap widened especially in wealthy countries. In developed nations, better medical services raised life expectancy, but healthy life expectancy did not increase by as much.
On the 21st, Christopher Murray and a team at the Institute for Health Metrics and Evaluation (IHME) at the University of Washington published the 2023 Global Burden of Disease (GBD) findings in the journal Lancet Public Health. The study measured the morbidity gap—the difference between life expectancy and healthy life expectancy—across 204 countries between 1990 and 2023.
◇Healthy life expectancy did not rise in step with life expectancy
According to the paper, the morbidity gap widened in nearly all places over this period. It grew from 8.8 years in 1990 to 10.7 years in 2023. That means people are spending more time in poor health worldwide. On average, people spent 14.5% of their lives in an unhealthy state, up from 13.6% in 1990.
The study is based on life expectancy at birth, an estimate of how long people will live. Between 1990 and 2023, life expectancy rose from 64.6 years to 73.8 years. At the same time, healthy life expectancy—the time spent living daily life in good health without disease—increased from 55.9 years to 63.1 years, but it failed to keep pace with gains in life expectancy, leading to a steady rise in the time lived with chronic disease and disability.
The team said the COVID-19 pandemic caused temporary changes but did not reverse the larger trend of a widening morbidity gap. Due to the pandemic, global life expectancy fell to 71.9 years in 2021 and healthy life expectancy to 61.7 years. The global average morbidity gap narrowed by 0.1 years, from 10.4 years in 2020 to 10.3 years in 2021. This was interpreted not as people suddenly becoming healthier, but as life expectancy dropping more sharply than healthy life expectancy.
Murray said, "These findings suggest that future health gains can be achieved not only by extending life expectancy but also by improving health," adding, "Progress in healthy aging should be measured by healthy life expectancy as well as life expectancy, and we should invest more in disease prevention, long-term disease management, and chronic disease treatment to reduce the time spent in poor health."
◇The higher the income level of a country, the larger the morbidity gap
High-income countries are thought to have better medical infrastructure and thus healthier, longer lives than low-income countries, but the reality was different. Where people receive more medical benefits, more live longer, but the burden of chronic disease has also risen. As of 2023, the morbidity gap was largest in the United States at 14 years, followed by Australia (13.9 years), Canada (13.7 years), New Zealand (13.1 years), and the Netherlands (12.9 years). In Korea, it increased from 9.4 years in 1990 to 11.6 years in 2023, ranking 48th.
By contrast, sub-Saharan Africa had the smallest morbidity gap at 9.0 years. This does not mean people there are healthier; rather, because overall life expectancy is shorter, the time lived with illness or disability is also shorter. As of 2023, North Korea ranked 146th out of 204 countries, with a 9.4-year gap between life expectancy and healthy life expectancy.
By sex, women lived longer but spent more time in poor health. In 2023, women's average morbidity period was 12.1 years, longer than men's 9.3 years. This was true in both high- and low-income countries. The researchers said this shows that although women live longer than men, they also live longer with disease and disability regardless of the level of socioeconomic development.
A small number of chronic diseases accounted for most of the increase in time lived with illness. As of 2023, the team said chronic diseases made up 57.4% of all time spent in poor health. Musculoskeletal disorders—especially low back pain—were the leading contributors to the morbidity gap, followed by mental disorders such as depression and anxiety, sensory organ disorders including age-related hearing loss, and injuries such as falls.
The team said there are relatively easy ways to prevent the morbidity gap. Even without breakthrough treatments, changes in lifestyle and focused medical investment can address much of the problem. Globally, elevated fasting plasma glucose levels, high body mass index, child and maternal malnutrition, and smoking were identified as major risk factors contributing to the morbidity gap. Air pollution also ranked among the top five risk factors.
References
Lancet Public Health (2026), DOI: https://doi.org/10.1016/S2468-2667(26)00098-8