A study of the test–retest reliability of the self-perceived general recovery and self-perceived change in neck pain questions in patients with recent whiplash-associated disorders

The objectives of this study were to determine the test–retest reliability of two self-perceived recovery questions in patients with recent whiplash-associated disorders (WAD), and to assess whether remembering previous answers influences reliability. The self-perceived general recovery and self-perceived change in neck pain questions were administered to 46 patients with recent WAD 6 weeks after recruitment and again 3–5 days later. At follow-up, we also asked participants if they remembered their previous answers. We used the intra-class correlation coefficients (ICC) to measure the reliability of the original ordinal response structure and kappa statistics for dichotomized responses. The ICC [95% confidence intervals (CI)] for the general recovery and for the change in neck pain questions were 0.70 (0.60–0.80) and 0.80 (0.72–0.87), respectively. The kappa statistic (95% CI) for the general recovery question was 0.81 (0.64–0.99) when recovery was defined as “completely better” or “much improved”. The kappa statistic (95% CI) for the change in neck pain question was 0.80 (0.62–0.99) when recovery was defined as “very much better” or “better”. Our analysis suggests that the test–retest reliability may be higher for participants who remembered their previous responses. In conclusion, our results suggest that self-perceived recovery questions have adequate reliability for use in epidemiological research of WAD.