Longitudinal associations among quality of life and its predictors in patients treated for prostate cancer: the moderating role of age.

This study examined moderating effects of age on longitudinal associations among quality of life (QOL) and its demographic (e.g., age), clinical [e.g., prostate-specific antigen (PSA) level], and affective and cognitive predictors (i.e., distress, worries about recurrence, decisional regret, subjective life expectancy) in prostate cancer patients treated with external beam radiation (N = 391). Demographic and clinical characteristics were assessed at diagnosis, affective and cognitive variables at 6 months after diagnosis, and QOL at 12 months after diagnosis. Multiple-group analyses showed that among younger patients (< or =68 years old, n = 199), lower levels of decisional regret were associated with better functional QOL, and lower Gleason scores and PSA levels were associated with lower levels of distress and longer expected survival time, respectively. Being employed was related to higher levels of functional QOL and frequent worries about recurrence. Among older patients (>68 years old, n = 192), lower levels of distress were associated with higher levels of functional QOL, and longer expected survival time was associated with better functional and physical QOL.