Objectives: To test the effect of psychological intervention on multiple medically unexplained physical symptoms, psychological symptoms, and health care utilization in addition to medical care as usual. To identify patient-related predictors of change in symptoms and care utilization.
Methods: In a randomized controlled trial, subjects were assigned to one of two conditions: psychological intervention by a qualified therapist plus care as usual by a general practitioner (GP) or care as usual only. Participants (N=98) were administered a standardized interview and several outcome measures at intake and after 6 months and 12 months after intake. GPs rated medically unexplained and explained symptoms and consultations over a period of 1 1/2 years.
Results: ANOVAs for repeated measures showed that self-reported and GP-registered unexplained physical symptoms decreased from pretest to posttest to follow-up. Psychological symptoms and consultations decreased from pretest to posttest. GP-registered explained symptoms did not decrease. However, intervention and control groups did not differ in symptom reduction. Path analysis revealed two paths to a decrease in self-reported unexplained physical symptoms: from more negative affectivity via more psychological attribution and more pretreatment anxiety, and from more somatic attribution via more psychological attribution and more pretreatment anxiety.
Conclusion: Intervention and control groups did not differ in symptom reduction. Reduction of self-reported medically unexplained symptoms was well predicted by patient-related symptom perception variables, whereas the prediction of change in registered symptoms and consultations requires a different model.