However, it is also useful in assessing the success of interventions to reduce BP. 3.2. Lifetime Risk of Hypertension Observational studies have documented a relatively high inci- dence of hypertension over periods of 5 to 10 years of follow- Thus, there is a much higher long-term population burden of hypertension as BP progressively increases with age. Several studies have estimated the long-term cumulative inci- dence of developing hypertension.S3.2-3,S3.2-4 In an analysis of 1132 white male medical students (mean age: approximately 23 years at baseline) in the Johns Hopkins Precursors study, In MESA (Multi-Ethnic Study of Atherosclerosis), the percentage of the population develop- ing hypertension over their lifetimes was higher for African Americans and Hispanics than for whites and Asians.S3.2-3 For adults 45 years of age without hypertension, the 40-year risk of developing hypertension was 93% for African-American, 92% for Hispanic, 86% for white, and 84% for Chinese In the Framingham Heart Study, approximately 90% of adults free of hypertension at age 55 or 65 years devel- oped hypertension during their lifetimes.S3.2-4 All of these esti- mates were based on use of the 140/90 mm Hg cutpoint for recognition of hypertension and would have been higher had the 130/80 mm Hg cutpoint been used. 3.3. Prevalence of High BP Prevalence estimates are greatly influenced by the choice of cutpoints to categorize high BP, the methods used to estab- lish the diagnosis, and the population studied.S3.3-1,S3.3-2 Most general population prevalence estimates are derived from national surveys. Table 7 provides estimates for prevalence of hypertension in the US general adult population ( 20 years of age) that are based on the definitions of hypertension rec- ommended in the present guideline and in the JNC 7 report. 