Health sensitivity: Age differences in the within-person coupling of individuals' physical health and well-being

Well-being and physical health are central indicators of quality of life in old age. Research from a between-person difference perspective finds that people in better health than their peers also report higher well-being than their peers. However, we know very little about whether changes in one domain are accompanied by changes in the other domain, particularly at the within-person level. In the present study, we introduce the construct of health sensitivity, that is, how susceptible an individuals' well-being is to changes in physical health. In doing so, we used 9-wave longitudinal data covering 17 years from the Health and Retirement Study (N = 21,689; 50-109 year olds; 55% women) and applied multilevel modeling to examine the covariation of central indicators of well-being (depressive affect) and health (functional limitations) simultaneously at both the between-person and within-person level. At the within-person level, we found evidence of health sensitivity-on occasions when a typical person experienced more functional limitations than usual, he or she also reported more depressive affect-and that health sensitivity decreased with age. Survival analysis revealed that health sensitivity was related to mortality hazards, controlling for mean levels of health and well-being. We discuss the theoretical importance of examining within-person associations between health and well-being and consider practical implications.