Study Design Secondary analysis of a prospective cohort study with cross-sectional and longitudinal analyses. Background The clinical importance of a history of whiplash-associated disorder (WAD) in people with neck pain remains uncertain. Objective To compare people with WAD to people with nonspecific neck pain, in terms of their baseline characteristics and pain and disability outcomes over 1 year. Methods Consecutive patients with neck pain who presented to a secondary-care spine center answered a comprehensive self-report questionnaire and underwent a physical examination. Patients were classified into a group of either those with WAD or those with nonspecific neck pain. We compared the outcomes of baseline characteristics of the 2 groups, as well as pain intensity and activity limitation at follow-ups of 6 and 12 months. Results A total of 2578 participants were included in the study. Of these, 488 (19%) were classified as having WAD. At presentation, patients with WAD were statistically different from patients without WAD for almost all characteristics investigated. While most differences were small (1.1 points on an 11-point pain-rating scale and 11 percentage points on the Neck Disability Index), others, including the presence of dizziness and memory difficulties, were substantial. The between-group differences in pain and disability increased significantly (P<.001) over 12 months. At 12-month follow-up, the patients with WAD had on average approximately 2 points more pain and 17 percentage points more disability than those with nonspecific neck pain. Conclusion People referred to secondary care with WAD typically had more self-reported pain and disability and experienced worse outcomes than those with nonspecific neck pain. Caution is required when interpreting the longitudinal outcomes due to lower-than-optimal follow-up rates. Level of Evidence Prognosis, level 2. J Orthop Sports Phys Ther 2016;46(10):894-901. Epub 3 Sep 2016. doi:10.2519/jospt.2016.6588.
Keywords: WAD; baseline characteristics; cervical spine; cohort study; prognosis.