Relations between fatigue, neuropsychological functioning, and physical activity after treatment for breast carcinoma: daily self-report and objective behavior

Background: Previous research indicates that disease free breast carcinoma survivors who experienced severe fatigue also had many problems with regard to neuropsychological functioning and physical activity, measured with general self-report questionnaires. Both neuropsychological functioning and physical activity can be measured with daily self-report measures in addition to measures of objective behavior. The main objective of this study was to examine the relations between 1) fatigue and 2) daily self-reported and objective measures of neuropsychological functioning and physical activity.

Methods: Disease free breast carcinoma survivors and age-matched women with no history of breast carcinoma filled out a daily self-observation list and wore an actometer during a period of 12 days. Furthermore, they performed two standardized tests to assess neuropsychological functioning.

Results: No differences were found between severely fatigued disease free breast carcinoma survivors, nonseverely fatigued disease free breast carcinoma survivors, and women in a control group with regard to daily self-reported and objective physical activity. The severely fatigued disease free patients reported more impairment in neuropsychological functioning on daily questionnaires compared with nonseverely fatigued disease free patients and women in the control group. However, no differences were found between these three groups on a standardized concentration task. On a standardized reaction time task, no significant differences were found between the two groups of disease free breast carcinoma survivors: However, women in the severely fatigued group had a significantly longer reaction time compared with women in the control group.

Conclusions: Fatigue is correlated strongly with daily self-reported neuropsychological functioning, but not with objective neuropsychological functioning, in a laboratory setting. In the current study, fatigue was not correlated with daily self-reported and objective physical activity.