RT Journal Article
SR Electronic
T1 Heterogeneity Within the Fibromyalgia Population: Theoretical Implications of Variable Tender Point Severity Ratings
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP jrheum.090432
DO 10.3899/jrheum.090432
A1 Hilary D. Wilson
A1 Terence W. Starz
A1 James P. Robinson
A1 Dennis C. Turk
YR 2009
UL http://www.jrheum.org/content/early/2009/11/16/jrheum.090432.abstract
AB Objective The American College of Rheumatology (ACR) tender point (TP) criterion is used in diagnosing fibromyalgia syndrome (FM). There has been little research investigating patterns of positive TP. We investigated response patterns of TP in a sample of patients with FM. Methods Manual TP survey data were available on 1433 patients with FM. Factor analysis was conducted on ACR TP and control (CON) points. Factor scores were cluster analyzed to identify subgroups based on TP scores. Subgroups were compared on demographic and psychosocial variables. Results Factor analysis resulted in 4 TP groupings: neck/shoulder girdle, gluteal/trochanteric, and upper extremity regions, and a set of CON TP. Cluster analysis revealed 3 clusters. Group 1 was high on all 3 TP regions and the CON set; Group 2 moderate on the 3 TP regions, low on the CON set; and Group 3 was relatively low on all 3 TP regions and the CON set. The group highest on the CON and TP regions reported the greatest pain (7.58 ± 1.23; p < 0.001), sleep disturbance (7.05 ± 1.61; p < 0.001), anxiety (10.14 ± 4.57; p < 0.001), and depression (8.42 ± 4.4; p < 0.001). Conclusion TP severity ratings varied among cluster groups, suggesting patients with FM are not homogeneous. Variations in TP severity provide information regarding the degree to which FM affects patients’ quality of life. Patients with elevated scores on the CON TP demonstrated a general pattern reflecting lower thresholds for symptom reporting and, perhaps, disease severity. Research is needed to elucidate mechanisms underlying heterogeneity among the FM population.