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 regres- sion models were constructed to examine predictors of varia- tions in vitality, pain, reduced activity and physical fatigue.
General fatigue accounted for 68% of the variation in vitality. Of this, 91% was accounted for by physiologi- cal indicators. After controlling for age, physiological para- meters 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.
The inflammatory processes were down-modulated by treatment with intravenous immunoglobulin followed by a clinical effect, especially on vitality, as evaluated by means of Short Form 36 (SF-36). This indicates that vitality has a central role in PPS that may be improved by means of phar- macological treatment. The subjective experience of vitality