Fibromyalgia diagnosis: a comparison of clinical, survey, and American College of Rheumatology criteria

Abstract

Objective: The American College of Rheumatology (ACR) criteria for fibromyalgia are the de facto criteria used for research. However, ACR criteria are not generally utilized by nonrheumatologists, and rheumatologists may diagnose fibromyalgia in patients who do not satisfy the ACR criteria. We undertook this study to determine concordance between ACR criteria and clinician diagnosis and between proposed survey criteria and clinician diagnosis.

Methods: Consecutive patients in a clinical practice setting were evaluated by tender point examination, survey criteria for fibromyalgia (Regional Pain Scale score > or =8 and fatigue score > or =6), and clinical diagnosis.

Results: Among the 206 patients, the clinician diagnosed fibromyalgia in 49.0%, while 29.1% satisfied ACR criteria and 40.3% satisfied survey criteria. Clinical and survey criteria were concordant in 74.8% of cases (kappa = 0.49 [95% confidence interval 0.36, 0.60]). Clinical criteria and ACR criteria were concordant in 75.2% of cases (kappa = 0.50 [95% confidence interval 0.35, 0.59]), and survey criteria and ACR criteria were concordant in 72.3% (kappa = 0.40 [95% confidence interval 0.25, 0.51]). The ACR tender point criterion (> or =11) was not a factor in clinical and survey criteria. However, the tender point count was useful in clinical diagnosis.

Conclusion: Clinical diagnosis and ACR and survey criteria are moderately concordant (72-75%) and address a common pool of symptoms and physical findings. Because there is no gold standard for fibromyalgia diagnosis and because fibromyalgia is often viewed as a trait diagnosis, all methods of diagnosis have utility. The survey method has the advantage that it does not require physical examination.