Age period cohort analysis of rheumatic heart disease in high-income countries

Rheumatic heart disease is considered well-controlled in high-income countries; however, its actual trends in mortality remain unclarified. We analyzed trends in mortality from rheumatic heart disease in association with age, period, and birth cohort.

We analyzed the WHO mortality database to determine trends in mortality from rheumatic heart disease in the UK, Germany, France, Italy, Japan, Australia, USA, and Canada from 2000 to 2020. We used age-cohort-period modeling to estimate cohort and period effects. Net drift (overall annual percentage change), local drift (annual percentage change in each age group) and heterogeneity were calculated.

In the most recent year, crude mortality rates and age-standardized mortality rates ranged from 1.10 in the USA to 6.17 in Germany, and 0.32 (95% CI 0.31–0.34) in Japan and 1.70 (95% CI 1.65–1.75) in Germany, respectively. During the observation period, while Germany had a constant trend in overall annual percentage change, all the other countries had significant decreasing trends (p < 0.0001, respectively). Annual percent change was not homogeneous across each group in all 8 countries (p_{heterogeneity} < 0.0001), with 2 peaks in the younger and older age categories. In Germany, Italy, Australia, and Canada, we found increasing mortality rates among older patients. Improving period and cohort risks for rheumatic heart disease mortality were generally observed, excluding Germany where the period effect was worsening and the cohort effect was constant.

Mortality trends from rheumatic heart disease were decreasing in the study high-income countries except for Germany where higher mortality and two peaks in annual percentage change in younger and older age groups warrant further investigation.