Time Trends in Cardiovascular Disease Mortality Across the BRICS: An Age-Period-Cohort Analysis of Key Nations With Emerging Economies Using the Global Burden of Disease Study 2017.

Abstract

Brazil, Russia, India, China, and South Africa (BRICS) are emerging economies making up almost half the global population. We analyzed trends in cardiovascular disease (CVD) mortality across the BRICS and associations with age, period, and birth cohort. Mortality estimates were derived from the Global Burden of Disease Study 2017. We used age-period-cohort modeling to estimate cohort and period effects in CVD between 1992 and 2016. Period was defined as survey year, and period effects reflect population-wide exposure at a circumscribed point in time. Cohort effects are defined as differences in risks across birth cohort. Net drift (overall annual percentage change), local drift (annual percentage change in each age group), longitudinal age curves (expected longitudinal age-specific rate), and period (cohort) relative risks were calculated. In 2016, there were 8.4 million CVD deaths across the BRICS. Between 1992 and 2016, the reduction in CVD age-standardized mortality rate in BRICS (-17%) was less than in North America (-39%). Eighty-eight percent of the increased number of all-cause deaths resulted from the increase in CVD deaths. The age-standardized mortality rate from stroke and hypertensive heart disease declined by approximately one-third across the BRICS, whereas ischemic heart disease increased slightly (2%). Brazil had the largest age-standardized mortality rate reductions across all CVD categories, with improvement both over time and in recent birth cohorts. South Africa was the only country where the CVD age-standardized mortality rate increased. Different age-related CVD mortality was seen in those ≥50 years of age in China, ≤40 years of age in Russia, 35 to 60 years of age in India, and ≥55 years of age in South Africa. Improving period and cohort risks for CVD mortality were generally found across countries, except for worsening period effects in India and greater risks for ischemic heart disease in Chinese cohorts born in the 1950s and 1960s. Except for Brazil, reductions of CVD mortality across the BRICS have been less than that in North America, such that China, India, and South Africa contribute an increasing proportion of global CVD deaths. Brazil's example suggests that prevention policies can both reduce the risks for younger birth cohorts and shift the risks for all age groups over time.