Increases in the life expectancy of global populations will be registered as a societal achievement. Increasing lifespan, however, does not imply an increase in healthy life; rather, how much of life is lived in good health is becoming increasingly relevant in quality of life. To this end, it would be valuable to characterize healthspan–the years lived in good health.
An approximation of health span is health-adjusted life expectancy wherein years of life are discounted according to health status. Health-adjusted life expectancy measures healthy longevity, being an aggregate indicator of health and quality of life. On reflection, although there is an extension of life, this has not been accompanied by a corresponding increase in health-adjusted life expectancy. The resulting lifespan gap reflects the extent of lifespan burdened by disease. This remains an area of study within longevity research.
Health-adjusted life expectancy, a measure of healthy longevity, lags longevity gains, resulting in a healthspan-lifespan gap. To quantify the healthspan-lifespan gap across the globe, investigate for sex disparities, and analyze morbidity and mortality associations.
The years counted as lived in disease or disability are represented by the healthspan-lifespan gap – the difference between life expectancy and health-adjusted life expectancy. The healthspan-lifespan gap thus increased worldwide between 2000 and 2019, with life expectancy increasing disproportionately compared to health-adjusted life expectancy, going from 8.5 years to 9.6 years over the same period, which goes on to reflect a staggering 13% adjustment over 20 years. The mean health-adjusted life expectancy in the 183 member states of WHO is 63.3 years, as against a mean life expectancy of 72.5 years (P <.001). An overall substantive lag in health span, across the globe. The mean lifespan revealed a gap of 9.2 years across WHO member states.
This study collects national-level data regarding WHO member states from all continents from the WHO Global Health Observatory, for retrospective cross-sectional research. Thus, the total number of WHO member countries in this study was 183. Statistical analysis took place from January to May 2024. The data also represent 20 years of follow-up in longitudinal observation.
A span of 9.6 years was the global increase in the healthspan-lifespan gap over the last two decades across the 183 countries that are currently members of the World Health Organization. There was a gender difference, with women presenting a mean (SD) healthspan-lifespan gap of 2.4 (0.5) years wider than men (P < .001). Healthspan-lifespan gaps were positively associated with the burden of non-communicable diseases and with total morbidity but were negatively associated with mortality. The largest lifespan gap was found in the USA, which was 12.4 years, fueled by the rise in non-communicable diseases.
Life expectancy and health-adjusted life expectancy, along with the healthspan-lifespan gap, were measured for all member states under this study. A disaggregated assessment of the gap was made according to sex. Correlations of the gap with morbidity and mortality were done. This cross-sectional study quantified healthspan-lifespan gaps among 183 World Health Organization member states. Globally, the mean healthspan-lifespan gap was 9.6 years, and women exhibited a mean 2.4-year larger gap than men, associated with a disproportionately larger burden of noncommunicable diseases in women.
However, the present study has its limitations. This span pertains to the period during which an individual spends in diseased life. It is dependent on estimates regarding life expectancy and health-adjusted life expectancy. Compute health-adjusted life expectancy using the average number of years lived in full health, depending on the different disability weights applied to health conditions. These weights have been revised further using different surveys across cultures, and as such, reflect multicultural perspectives. The weights may also be subjected to severe influence from the methodology or disproportionate representation of unaffected individuals in surveys.
The survey of healthspan-lifespan gaps among 183 WHO countries has found increasing healthspan-lifespan gaps globally. The observed gap was larger among women. The US had the greatest lifespan gap as well as a heavier burden of noncommunicable diseases. These results show that while people all over the world live longer, they suffer from a greater number of years of suffering from disease. To find out the determinants of the healthspan-lifespan gap, one needs to explore the various geography-associated demographic, health, and economic characteristics.
Reference: Garmany A, Terzic A. Global Healthspan-Lifespan Gaps Among 183 World Health Organization Member States. JAMA Netw Open. 2024;7(12):e2450241. doi:10.1001/jamanetworkopen.2024.50241
