In recent decades, clinical and public health efforts to reduce the burden of cardiovascular disease have emphasized the importance of calculating global, short-term (generally 10-year) risk estimates. However, the majority of adults in the United States who are considered to be at low risk for cardiovascular disease in the short term are actually at high risk across their remaining lifespan. Estimates of the lifetime risk of cardiovascular disease provide a more comprehensive assessment of the overall burden of the disease in the general population, now and in the future, because they take into account both the risk of cardiovascular disease and competing risks (e.g., death from cancer) until participants reach an advanced age. Such estimates can help guide public health policy, allowing projections of the overall burden of cardiovascular disease in the population.

Most estimates of the lifetime risk of cardiovascular disease have been derived from analyses restricted to risk factors measured at a single age in a predominantly white population.6,7 These estimates do not account for the potential effects of birth cohort that may arise from secular changes in risk-factor levels8,9 or for the widespread use of medical treatment, which has translated into marked reductions in rates of cardiovascular events in the United States.10

The Cardiovascular Lifetime Risk Pooling Project was designed to collect and pool data from numerous longitudinal epidemiologic cohort studies conducted in the United States over the past 50 years. This pooling approach provides an opportunity to calculate estimates of the lifetime risk of cardiovascular events according to age, sex, race, and other risk factors across multiple birth cohorts that would not be feasible within any one data set alone.

Study Sample

We included data sets in the Cardiovascular Lifetime Risk Pooling Project if they met the following criteria: they represented either community-based or population-based samples or large volunteer cohorts, they included at least one baseline examination with direct measurement of physiological and anthropometric (e.g., weight) variables, and they included 10 or more years of follow-up for fatal or nonfatal cardiovascular events or both. Data from 18 unique cohorts were included in the study, 17 of which were included in the pooled analysis. Because of the large size of one study, the Multiple Risk Factor Intervention Trial (MRFIT), relative to the other 17 studies, this cohort was analyzed separately. All data were appropriately de-identified, and all study protocols and procedures were approved by the institutional review board at Northwestern University.

Ascertainment of Baseline Measures and Follow-up Events

The protocols used to obtain data on demographic characteristics, personal and medical history, physical examination, laboratory results, and follow-up procedures for ascertainment of vital status and events for all cohorts included in the study have been published elsewhere. Blood pressure and serum cholesterol levels were measured directly in all participants; data on smoking status were self-reported, as were data on diabetes status, the latter derived from records of self-report, use of medication for diabetes, or both. Events were ascertained with the use of strategies selected by each cohort’s investigator group and included death from cardiovascular disease, from coronary heart disease, or from any cause and nonfatal events of interest, including myocardial infarction and stroke.