Belloc, N. B., L Breslow and J. R. Hochstim (Calif. State Dept. Public Health, Berkeley 94704). Measurement of physical health in a general population survey. Amer J Epidem 93: 328–336, 1971.—This paper presents a new and more general approach to the measurement of health in a population. In a survey of a sample of the adult population of Alameda County, California, in 1965, respondents were asked a number of questions regarding disability, chronic conditions, symptoms and energy level. From their responses, they have been categorized along a physical health spectrum ranging from a minimum state defined by inability to work and/or care for personal needs, to an optimal state expressed by no complaints and a high level of energy. The summary measure, the mean ridit, utilizes the distribution along the entire spectrum, enables the comparison of subgroups within the population, and allows for adjustment of differences due to selected characteristics, such as age and sex. The health of population subgroups was examined for selected demographic variables, including race, occupation, education, employment and marital status. There was a marked linear relationship with age, the mean ridit for the oldest group being nearly double that of the youngest group. Men were slightly more healthy than women, and those with inadequate family incomes were less healthy than those with marginal or adequate incomes.