Modifiable risk factors, cardiovascular disease and mortality in 155,722 individuals from 21 high-, middle-, and low-income countries

Background: Global estimates of the impact of common modifiable risk factors on cardiovascular disease (CVD) and mortality are largely based on data from separate studies, using different methodologies. The Prospective Urban Rural Epidemiology (PURE) study overcomes these limitations by using similar methodology to prospectively evaluate the impact of modifiable risk factors on CVD and mortality across 21 countries (spanning five continents) at different economic levels. Methods: In a multi-national, prospective cohort study, we examined associations for 14 potentially modifiable risk factors with mortality and major CVD in 155,722 community-dwelling participants (ages 35–70 years at enrollment) from 21 high-, middle-, or low-income countries (HIC, MIC or LIC) followed for a median of 9·5 years. We describe the prevalence, hazard ratios, and population attributable fractions (PAFs) for CVD and mortality associated with a cluster of behavioural factors (i.e. tobacco, alcohol, diet, physical activity and sodium intake), metabolic factors (i.e. lipids, blood pressure, diabetes, obesity), socioeconomic and psychosocial factors (i.e. education, symptoms of depression), strength, household (solid fuel for cooking) and ambient PM 2·5 air pollution. Findings: Mean age of the population was 50·2 years of age, 58·3% were female, 52·6% were from urban areas, 11·1% from HIC, 65·9% from MIC, and 23·0% from LIC. Over 70% of CVD cases and deaths in the overall cohort were attributed to modifiable risk factors. Metabolic factors were the predominant risk factors for CVD (41·2% of the PAF), with hypertension being the largest (22·3% of the PAF). As a cluster, behavioural risk factors contributed most to deaths (26·3% of the PAF), although the single largest risk factor was a low education level (12.5% of the PAF). Ambient air pollution was associated with 13·9% of the PAF for CVD (although different statistical methods were used for this analysis). In MIC and LIC, the importance of household air pollution, poor diet, low education, and low grip strength were larger compared with HIC. Interpretation: The majority of CVD cases and deaths can be attributed to a small number of common, modifiable risk factors. While some factors have extensive global impacts (e.g. hypertension, education), others (e.g. household air pollution, poor diet) vary by a country’s economic level. Health policies should focus on risk factors that have the greatest effects on averting CVD and death globally, with additional emphasis on risk factors of greatest importance in specific groups of countries.