Inter-rater reliability of the Quebec Task Force classification system for recent-onset Whiplash Associated Disorders.

Purpose The inter-rater reliability of the Quebec Task Force (QTF) classification system for Whiplash-Associated Disorders (WAD) remains unknown. Our objective was to determine the inter-rater reliability of the WAD classification between an experienced chiropractic clinician and two chiropractic residents. Methods We conducted an inter-rater reliability study using baseline clinical data from 80 participants assessed for inclusion in a randomized clinical trial of the conservative management of WAD grades I and II. We reported reliability using Cohen's kappa (k) and 95% confidence intervals (CI). Results The mean duration of WAD symptoms was 7.6 days (s.d.=5.2). In our study, the interrater reliability of the WAD grade classification varied from k=0.04 (95% CI -0.04 to 0.12) to k=0.80 (95% CI 0.67 to 0.94). Conclusion Inter-rater reliability of the WAD classification varied greatly across raters and may be associated with the experience of the raters and with their understanding of the criteria. Our results suggest that clinicians may benefit from training to standardize how they classify WAD. Furthermore, our results need to be tested in a different sample of patients and with a range of clinicians from different clinical disciplines.