Vitality among Swedish patients with post-polio: a physiological phenomenon.

OBJECTIVE To evaluate vitality and fatigue in post-polio patients, and the relative contributions of physiological and psychological parameters to the level of vitality. DESIGN Multi-centre study. SUBJECTS One hundred and forty-three patients with post-polio syndrome. METHODS Inventories of background, quality of life, fatigue and sleep quality were used. Pain was evaluated using a visual analogue scale. Descriptive statistics and correlations were used for all selected parameters. Hierarchical regression models were constructed to examine predictors of variations in vitality, pain, reduced activity and physical fatigue. RESULTS General fatigue accounted for 68% of the variation in vitality. Of this, 91% was accounted for by physiological indicators. After controlling for age, physiological para notmeters accounted for 56.6% and 25%, if entered before and after the psychological parameters, respectively. The impact of the psychological parameters decreased after accounting for the physiological parameters. Physical fatigue, age and sleep quality were associated with variation in pain. Body mass index, pain and sleep quality accounted for differences in reduced activity and physical fatigue. CONCLUSION Vitality in post-polio patients depends on physio-logical parameters. Mental fatigue is not a prominent predictor. Subgroups with or without fatigue, independent of age, need further study.