The contributions of risk factors on health adjusted life expectancy (HALE) changes from 1990 to 2017: A serial cross-sectional analysis from the GBD study

The application of health adjusted life expectancy (HALE) in informing policy-making decisions and prioritizing health interventions require reliable quantitative and comparative information. To quantify how risk factors affect HALE from 1990 to 2017 and associations with attributable diseases and injuries, we conducted a demographic analysis using serial cross-sectional data from the Global Burden of Disease (GBD) Study 2017 and analysed risk-specific contribution to changes in HALE at birth (HALE₀) globally and by 21 regions, and 195 countries and territories. From 1990 to 2017, global HALE₀ increased by 6.33 years, of which 3.94 years were attributed to all designated risks. Specifically, 2.38 years came from improvement in behavioural risks, followed by 1.20 years from environmental and occupational risks. The top three contributors to increased HALE₀ were due to better control of child growth failure (0.68 years), household air pollution from solid fuels (0.47 years), and smoking (0.42 years). The leading risks causing HALE₀ decrease were high body-mass index (BMI, −0.08 years), unsafe sex (−0.07 years) and drug use (−0.03 years). These HALE₀ decreases were linked to diabetes, HIV/AIDS, and drug use disorders, respectively. The largest decline in HALE₀ across countries was due to high BMI (in 61 countries), unsafe sex (34), and drug use (29). Improved control of behavioural and environmental risks contributed most to increase in population health. Individual risk factors with negative contributions require future effective interventions to reversing the effects. This quantitative analysis highlights the potential roadmaps for sustained interventions on specific risk factors globally and locally.