The sex differential in mortality rates: demographic and behavioral factors.

By using the 1965 Human Population Laboratory Survey of a random sample of 6928 adults in Alameda County, California, and a nine-year follow-up, mortality risk is examined by sex, while simultaneously controlling for 16 demographic and behavioral risk factors by a multiple logistic analysis. Risk factors include age, race, socioeconomic status, occupation, physical health status, use of health services, smoking, alcohol consumption, physical activity, weight, sleeping patterns, marital status, social contacts, church and group membership and life satisfaction. The prevalence and relative mortality risk of each factor combine to influence the sex differential. The unadjusted relative mortality risk for men compared to women is 1.5 (p less than or equal to 0.001). Adjustment for some factors (e.g., smoking and alcohol) decreases this difference, while other adjustments (e.g., for physical activity, physical health status and marital status) increase the difference. Adjustment for all 16 factors slightly increases the relative risk to 1.7 (p less than or equal to 0.001). These demographic and behavioral risk factors do not account for the overall sex difference in mortality rates. Examination of the interaction of biologic and behavioral risk factors may more fully explain the sex differential in mortality.