Emotional well-being predicts subsequent functional independence and survival

OBJECTIVE: To determine whether positive affect has an independent effect on functional status, mobility, and survival in an older Mexican American sample. DESIGN: A 2-year prospective cohort study. SETTING: Five Southwestern states: Texas, California, Arizona, New Mexico, and Colorado. PARTICIPANTS: A population-based sample of 2282 Mexican Americans aged 65 to 99 who reported no functional limitations at baseline interview. MEASUREMENTS: In-home interviews in 1993-1994 and again in 1995-1996 assessed demographic variables, health conditions, activities of daily living, performance-based mobility, survival, and a rating of positive and negative affect. RESULTS: In multivariate analyses, there was a direct relationship between positive affect scores at baseline and mobility, functional status, and survival 2 years later, controlling for functional status, sociodemographic variables, major chronic conditions, body mass index (BMI), smoking status, drinking status, and negative affect at baseline. Subjects with high positive affect were half as likely (odds ratio (OR) = 0.48; 95% confidence interval (CI) 0.29, 0.93) to become disabled in activities of daily living (ADLs), two-thirds as likely (OR = 0.64; 95% CI 0.51, 0.79) to have a slow walking speed, and half as likely (OR 0.53; 95% CI 0.30, 0.93) to have died during the 2-year follow-up compared to those with lower positive affect scores. CONCLUSIONS: Our results support the concept that positive affect, or emotional well-being, is different from the absence of depression or negative affect. Positive affect seems to protect individuals against physical declines in old age.