Reliability and Reproducibility of Fibromyalgic Tenderness, Measurement by Electronic and Mechanical Dolorimeters

Abstract

Objectives: To compare an electronic dolorimeter to a mechanical dolorimeter in the measurement of fibromyalgic tenderness, and to determine which factors contribue to variation in the measurement of tenderness. Methods: Seventy-two adult female patients satisfying 1990 classifaction criteria for fibromyalgia were emained at 6 fibromyalgic tender points by 4 examiners using 2 electronic dolorimeters and 2 x 9 kg Chatillon mechanical dolorimeters. The order of examination and the assignment of instruments to examiners was randomized according to a Graeco-Latin square design. Analysis of variance and of components of variation was performed on the total dolorimetry score for each patient. Results: Virtually identical mean dolorimetry scores were obtained with the 2 Chatillon dolorimeters. Scores with the 2 electronic dolorimeters differed significantly from each other and from the mechanical dolorimeter scores. Other significant sources of variation in tenderness were emaination sequence and interobserver variation. Measurements with the mechanical dolorimeters demonstrated high reliability coefficients [80-85%]. Electronic dolorimeter data showed fair to good reliability [65-72%]. Conclusions: Measurements of fibromyalgic tenderness with the mechanical dolorimeter are highly reproducable; measurements with the electronic dolorimeter show lesser, but still good, reliability. Further studies with the electronic dolorimeter are feasible.

KEYWORDS:

• Dolorimetry
• fibromyalgia
• fibrositis
• tenderness