Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Fibromyalgia Diagnosis Is Significantly Impacted by the Number of Tender Points Presented on Patient Physical Exam.

Starz1,  Terence W., Sanchez2,  Robert J., Duncan3,  Bruce, Ka3,  Kaite, Pinner2,  Elizabeth, Gruen2,  Shera D., Turk4,  Dennis C.

Arthritis & Internal Med Associates, Pittsburgh, PA
Pfizer
Roger Green and Associates
University of Washington, Seattle, WA

Statement of Purpose:

To evaluate whether the number of tender points (TP) in simulated case vignettes influenced the likelihood of primary care physicians (PCPs) and rheumatologists (RHEUMs) diagnosing fibromyalgia (FM).

Methods:

200 PCPs and 100 RHEUMs experienced in treating chronic pain were recruited from an online panel to review simulated patient cases. All simulated patient cases included chronic wide spread pain (CWP) + varying degrees of painful TPs (3–4, 6–8, and 10–12) on physical examination and various constellations of other FM related-symptoms (Table 1).

Each physician evaluated 20 cases and was asked to provide a diagnosis. The primary outcomes of interest were the diagnosis of FM, which was based on groups that include descriptions of varying numbers of TP present on physical examination and symptoms, by PCPs and RHEUMs. Bivariate statistics were used to examine the association between TPs and symptoms. Logistic regression models were used to examine predictors of FM diagnoses.

Results:

300 physicians reviewed 6000 simulated patient case vignettes. The overall FM diagnosis rate was 35% for PCPs and 63% for RHEUMs. The rate of FM diagnosis for the PCPs did not change among the different constellation of symptoms; however, as the number of painful TPs increased, the FM diagnosis also increased (Table 1). Among the RHEUMs, there was no significant difference in the dx rate among the different constellations of patient symptoms for those experiencing 3–4 or 6–8 painful TPs. However, among those with 10–12 painful TPs, a significant difference in diagnosis (67%–84%, p = 0.004) among the different constellation of patient symptoms were seen. The FM diagnosis rate for RHEUMs also increased as the number of TPs increased (Table 1). After controlling for covariates, the odds of an FM diagnosis among PCP was significant for those experiencing 6–8 painful TPs (odds ratio 1.82, p <.001) and 10–12 painful TPs (odds ratio 4.64, p<.001). Among the RHEUMs, the odds of an FM diagnosis was significant for those experiencing 6–8 painful TPs (odds ratio 1.57, p <.001) and 10–12 painful TPs (odds ratio 3.20, p <.001). The presence of 3–4 TPs did not impact the likelihood an FM diagnosis.

Conclusion:

Although not all simulated patient cases met the ACR FM diagnosis criteria, the diagnosis of FM by RHEUMs was consistently higher than the diagnosis by PCPs across the different patient TPs and symptom groups. When evaluating simulated patients with FM who are describing widespread pain with or without other FM symptoms and a variable number of tender points on physical examination, the number of tender points is the most significant patient characteristic that leads both primary care physicians and rheumatologists to make the diagnosis of FM. Further analysis is needed to understand reasons behind misdiagnosis.

To cite this abstract, please use the following information:
Starz, Terence W., Sanchez, Robert J., Duncan, Bruce, Ka, Kaite, Pinner, Elizabeth, Gruen, Shera D., et al; Fibromyalgia Diagnosis Is Significantly Impacted by the Number of Tender Points Presented on Patient Physical Exam. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :2246
DOI: 10.1002/art.30009

Abstract Supplement

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