DOUBLE JEOPARDY - INTERACTION EFFECTS OF MARITAL AND POVERTY STATUS ON THE RISK OF MORTALITY

The purpose of this paper is to examine the hypothesis that marital an d poverty status interact in their effects on mortality risks beyond t heir main effects. This study examines the epidemiological bases for a pplying an additive rather than a multiplicative specification when te sting for interaction between two discrete risk factors. We specifical ly predict that risks associated with being nonmarried and with being poor interact to produce mortality risks that are greater than each ri sk acting independently. The analysis is based on men and women who we re ages 25-74 during the 1971-1975 National Health and Nutrition Exami nation Survey I (NHANES I) and who were traced successfully in the NHA NES I Epidemiologic Follow-Up Study in 1982-1984. Overall, being both poor and nonmarried places nonelderly (ages 25-64) men, but not women, at risk of mortality greater than that expected from the main effects . This study shows that for all-cause mortality, marital and poverty s tatus interact for men but less so for women; these findings exist whe n interaction is assessed with either a multiplicative or an additive standard. This difference is most pronounced for poor, widowed men and (to a lesser degree) poor, divorced men. For violent/accidental death s among men, the interaction effects are large on the basis of an addi tive model. Weak main and interaction effects were detected for the el derly (age 65+).