Objective: Comparison of low back pain (LBP) patients with and without fibromyalgia syndrome (FMS) with regard to affective distress.
Methods: Patients with LBP who had been admitted to various clinics in Germany were examined upon admission. Comparisons were done by dividing the patients into groups with and without signs of FMS. Additionally, both groups were compared after being matched according to sex, age, and pain severity.
Results: 15 out of 135 LBP patients met the American College of Rheumatology criteria for fibromyalgia. Patients with FMS showed remarkably higher levels of pain severity and affective distress. After controlling for different levels of pain severity, these pronounced differences disappeared.
Conclusion: Affective distress is not a unique feature of FMS, but seem to be caused entirely by higher levels of pain severity.