Early multidisciplinary evaluation and advice was ineffective for whiplash-associated disorders

Abstract Background Whiplash is the most common type of injury reported in traffic accidents, but the effectiveness of conservative treatment for whiplash lacks evidence. Aims To assess the effect of early multidisciplinary evaluation and advice on the frequency of chronic neck pain three years post-injury in persons with minor or moderate traffic injuries. Methods In an insurance setting, we tested the effect by (1) a risk score matched prospective cohort design, (2) a propensity score matched nested case-control design and, (3) a risk and propensity score adjusted multivariate analysis in an unmatched prospective cohort design. We simulated unobserved risk and propensity factors to evaluate the robustness of the results for hidden bias. Results All three designs showed a significantly increased risk for chronic neck pain among those who received the intervention compared to those who did not. The relative risks ranged from 1.7 (95% CI: 1.0–2.6) to 2.6 (95% CI: 1.5–4.0). The results were robust to hidden bias. Conclusion The consistency of the findings across the different designs strongly suggest that early multidisciplinary evaluation and advice increased the risk of having chronic neck pain three years following a minor or moderate traffic injury. Literally, the intervention may therefore have done more harm than good.