Objective: To assess whether the fatigue commonly reported by patients following surgery is partly a result of somatization and/or cognitive-behavioral factors.
Methods: One hundred eighty-three patients completed questionnaires before surgery and then 2 days, 3 weeks and 6 months afterward. Multiple regressions were used to assess which of the following factors were important in predicting self-reported postoperative fatigue, controlling for preoperative fatigue and for various demographic and surgical variables: negative mood, history of mood disorder, preoperative expectations of fatigue, preoperative worry or optimism about surgery, preoperative beliefs about the benefits of activity or rest, self-reported postoperative activity, self-reported cardiovascular deconditioning, and availability of social support.
Results: Controlling for demographic and surgical variables and preoperative fatigue, postoperative fatigue showed significant associations with negative mood at each stage of follow-up (p < .001) and was significantly predicted by history of mood disorder at 2 days postoperatively (p = .02). Higher fatigue expectations were self-fulfilling at 3 weeks after surgery (p = .02), whereas preoperative belief in physical activity as being beneficial to recovery predicted reduced fatigue at 6 months (p < .001). Finally, self-reported breathlessness after exercise, an indicator of cardiovascular deconditioning, was also significantly associated with greater fatigue at 6 months (p = .02).
Conclusion: The results indicate that psychological processes may well be relevant in the etiology of postoperative fatigue. In particular, the results relating to mood and expectations suggest that somatization may be particularly important in the first few weeks following surgery, whereas cognitive-behavioral factors and cardiovascular deconditioning may be more important in determining later-stage recovery.
ASA status = American Society of Anesthesiologists physical status score; T1 = preoperative; T2 = 2 days postoperatively; T3 = 3 weeks postoperatively; T4 = 6 months postoperatively; GHQ-12 = General Health Questionnaire (12 items); STAI-6 = State Anxiety Inventory (6 items); IPQ-R = Revised Illness Perception Questionnaire.