Non-Organic Sign Testing Reliable in Low Back Pain
Interobserver reliability of the Waddell score is moderate and the intraobserver reliability is good
THURSDAY, April 10 (HealthDay News) -- When trained observers perform non-organic sign testing in patients with chronic low back pain, the interobserver reliability of the Waddell score is moderate and the intraobserver reliability is good, according to research published in the April issue of Spine.
Adri T. Apeldoorn, of the Vrije Universiteit Medical Centre in Amsterdam, the Netherlands, and colleagues studied 126 patients who were referred for rehabilitation. They used Cohen's κ to measure the interobserver and intraobserver reliability of the sign maneuvers, categories and Waddell score and Cronbach's α to calculate five categories and eight signs to determine internal consistency.
The researchers found that interobserver reliability ranged from 0.33-0.74 for the sign maneuvers and categories and from 0.48-0.49 for the overall Waddell score. They also found that intraobserver reliability ranged from 0.43-0.84 for the sign maneuvers and categories, and from 0.65-0.68 for the overall Waddell score, and that internal consistency ranged from 0.65-0.72 for the categories and from 0.71-0.78 for the signs.
"No influence of clinical characteristics was found on interobserver reliability," the authors conclude. "To optimize the homogeneity and variability of the Waddell score, we recommend summing up the individual signs instead of summing up the categories."