Life expectancy is a statistical measure of the average time an organism is expected to live, based on the year of their birth, their current age and other demographic factors including sex.Although healthy life expectancy has increased steadily in 191 of 195 countries (by 6.1 years) between 1990 and 2015, it has not risen as much as overall life expectancy (10.1 years), meaning people are living more years with illness and disability.
The burden of ill-health (measured in disability-adjusted life years, or DALYs ie, the burden of years lost to premature death and disability) has shifted from communicable, maternal, neonatal, and nutritional disorders (eg, HIV/AIDS, malaria, lower respiratory infections, diarrhoeal diseases, measles, and malnutrition) to disabling NCDs (eg, drug use disorders (particularly opioids and cocaine), hearing and vision loss, and osteoarthritis)—mainly due to increases in population numbers and ageing, a trend with massive implications for health systems and the costs of treatment.
