midlife predictors of healthrelated quality of life in older women background midlife represents an important time to evaluate health status and health behaviors that may affect healthrelated quality of life hrql in later years this study examines change in womens hrql over 11 years from ages 4759 to 5769 and identifies midlife characteristics that predict hrql at older agesmethods physical pcs and mental component summaries mcs of the sf36 were used to assess hrql from 2002 to 2013 in 2614 women from the study of womens health across the nation swan a multiethnicracial cohort study we used locally weighted scatterplot smoothing loess models to obtain unadjusted predicted mean trajectories of pcs and mcs as a function of ageresults loess predicted pcs declined from 516 to 471 whereas mcs increased from 492 to 531 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 raceethnicity was related to mcs but not pcsconclusions several potentially modifiable midlife factors such as improved sleep hygiene physical activity and body mass index might improve hrql for older women