In 1973-1974, the Hypertension Detection and Follow-up Program (HDFP) conducted a two-stage screening (home, clinic) for high blood pressure in fourteen communities. A similar two-stage screening was repeated in 1976-1977 for a stratified probability sample of those persons whose blood pressures were not definitely elevated at the 1973-1974 survey. This sample included: normotensives (not on antihypertensive medication), labile hypertensives (hypertensive at home visit but normotensive at the subsequent clinic visit) and controlled hypertensives (on medication with DBP less than 95 mm Hg at home screen). Of this sample, 86.1% were reexamined. A hypertensive in 1976-1977 was defined as an individual having DBP 95 mm Hg or greater or receiving physician-prescribed antihypertensive medication. The three-year incidence rate of hypertension was estimated to be 11.8% after one stage (home) screening and 9.0% after a two-stage (home and clinic) screening, with a black/white ratio > 2. Black men had higher rates than black women, but white women had higher rates than white men. The three-year incidence of hypertension was directly related to the initial blood pressure level. More than 51% of the new hypertensives were receiving treatment at the time of rescreening, and almost 90% of those treated were under control (DBP < 95 mm Hg). Among individuals under treatment in 1973-1974, 81.2% were still on treatment three years later. Of those who discontinued treatment prior to the 1976-1977 rescreening, blacks had higher blood pressure levels than whites. © 1982.