An Age-Period-Cohort Analysis of Cardiovascular Disease Mortality in the United States from 1999 to 2018

Abstract

BackgroundAlthough cardiovascular disease mortality rates in the United States declined from the 1970s to 2010s, they have now plateaued. The independent effects of age, period, and birth year (cohort) on cardiovascular disease mortality have not previously been defined. MethodsWe used data from the Centers for Disease Control and Prevention's Wide-Ranging Online Data for Epidemiologic Research to examine the effects of age, period, and cohort on cardiovascular disease mortality among individuals aged 20-84 years from 1999 to 2018, prior to the onset of the coronavirus disease 2019 pandemic. Age effects were described as cardiovascular disease-related mortality rates in each 5-year age group adjusted for year of death (period) and year of birth (cohort). Period and cohort effects were quantified as adjusted rate ratios (RRs) comparing cardiovascular disease mortality rates in each period and cohort to the reference periods and reference cohort (ie, 1919 birth cohort), respectively. ResultsBetween 1999 to 2018, there were 10,404,327 cardiovascular disease deaths among US adults. In each individual birth cohort, the age-specific cardiovascular disease mortality rates were stable between ages 20 through 39 years. Age-specific rates were higher for each year older between ages 40 through 84 years adjusting for period effects. The period cardiovascular disease mortality rates were lower in later periods (2004-2008 period RR 0.87, 95% confidence interval [CI] 0.85 to 0.88; 2009-2013 period RR 0.78, 95% CI 0.76 to 0.80) compared with the reference period (1999 to 2003) and plateaued thereafter. The cohort cardiovascular disease mortality rates were progressively lower in more recent birth cohorts (1924 birth cohort RR 0.85, 95% CI 0.83 to 0.87; 1974 birth cohort RR 0.29, 95% CI 0.27 to 0.32) compared with the reference cohort (1919 cohort) and plateaued thereafter. ConclusionAlthough cardiovascular disease mortality rates declined rapidly among those born between 1919 and 1974, improvements plateaued in birth cohorts thereafter even adjusted for period effects.