Variability Modifies Life Satisfaction's Association With Mortality Risk in Older Adults

Greater life satisfaction is associated with greater longevity, but its variability across time has not been examined relative to longevity. We investigated whether mean life satisfaction across time, variability in life satisfaction across time, and their interaction were associated with mortality over 9 years of follow-up. Participants were 4,458 Australians initially at least 50 years old. During the follow-up, 546 people died. After we adjusted for age, greater mean life satisfaction was associated with a reduction in mortality risk, and greater variability in life satisfaction was associated with an increase in mortality risk. These findings were qualified by a significant interaction such that individuals with low mean satisfaction and high variability in satisfaction had the greatest risk of mortality over the follow-up period. In combination with mean life satisfaction, variability in life satisfaction is relevant for mortality risk among older adults. Considering intraindividual variability provides additional insight into associations between psychological characteristics and health.