Midlife Predictors of Health-Related Quality of Life in Older Women.

Background: Midlife represents an important time to evaluate health status and health behaviors that may affect health-related quality of life (HRQL) in later years. This study examines change in women's HRQL over 11 years from ages 47-59 to 57-69 and identifies midlife characteristics that predict HRQL at older ages.

Methods: Physical (PCS) and mental component summaries (MCS) of the SF-36 were used to assess HRQL from 2002 to 2013 in 2,614 women from the Study of Women's Health Across the Nation (SWAN), a multiethnic/racial cohort study. We used locally weighted scatterplot smoothing (LOESS) models to obtain unadjusted predicted mean trajectories of PCS and MCS as a function of age.

Results: LOESS predicted PCS declined from 51.6 to 47.1, whereas MCS increased from 49.2 to 53.1. In multivariable models, controlling for baseline PCS, higher baseline physical activity (p = .002) and increase in physical activity from baseline (p < .0001) predicted better PCS. Time since baseline (ie, aging; p < .001), higher baseline body mass index (p < .0001), increased body mass index over time (p < .0001), smoking (p < .05), two or more medical conditions (p < .0001), sleep problems (p < .0001), and urinary incontinence (p < .0001) were related to lower PCS. Early (p = .004) and late postmenopause (p = .001; vs. premenopause) and aging (p = .05) predicted higher MCS. Predictors of lower MCS were less than very good health (p < .0001), sleep problems (p < .0001), stressful life events (p < .0001), higher perceived stress (p < .0001), and higher trait anxiety (p = .004). Race/ethnicity was related to MCS, but not PCS.

Conclusions: Several potentially modifiable midlife factors, such as improved sleep hygiene, physical activity, and body mass index, might improve HRQL for older women.