A cluster within the continuum of biopsychosocial distress can be labeled "fibromyalgia syndrome"--evidence from a representative German population survey

J Rheumatol. 2009 Dec;36(12):2806-12. doi: 10.3899/jrheum.090579. Epub 2009 Nov 16.


Objective: We tested the hypothesis that "fibromyalgia syndrome" is a biopsychosocial continuum disorder.

Methods: A cross-sectional survey of a representative sample of the German general population with persons >or= 14 years of age was conducted based on face-to-face contacts. Physical distress was measured by the regional pain scale (RPS) and the Patient Health Questionnaire 15 (PHQ-15), psychological distress by the PHQ-9, and social distress by the Oslo Social Support Scale. Health-related quality of life (HRQOL) was measured by the 12-item form of the Medical Outcome Study Short Form Health Survey. A k-means clustering procedure with 2-8 clusters preset was used to classify the scores of the RPS, PHQ-9, and PHQ-15. The number of clusters retained was based on the stability and interpretability of the clusters. The cluster analysis was first performed with a randomly selected half of the sample and then cross-validated on the second half of the total sample.

Results: A 4-cluster solution produced the most stable and meaningful results. Cluster 1 was very low on all symptom scores. Cluster 2 was low on pain sites, somatic symptoms, and depression. Cluster 3 was high on pain scores, moderate on somatic symptoms, and low on depression. Cluster 4 was high on all symptom scores. The centroids of cluster 4 met the survey criteria of fibromyalgia syndrome. Cluster 4 reported a lower HRQOL and less social support compared to the other 3 groups.

Conclusion: A cluster within the continuum of biopsychosocial distress can be labeled fibromyalgia syndrome.

MeSH terms

  • Adult
  • Cluster Analysis*
  • Cross-Sectional Studies
  • Disability Evaluation
  • Female
  • Fibromyalgia / classification
  • Fibromyalgia / physiopathology
  • Fibromyalgia / psychology*
  • Germany
  • Health Surveys
  • Humans
  • Male
  • Middle Aged
  • Psychiatric Status Rating Scales
  • Psychology*
  • Quality of Life
  • Stress, Psychological*
  • Surveys and Questionnaires
  • Young Adult