Factors predicting outcome in whiplash injury: a systematic meta-review of prognostic factors

BACKGROUND: Whiplash injuries are among the leading injuries related to car crashes and it is important to determine the prognostic factors that predict the outcome of patients with these injuries. This meta-review aims to identify factors that are associated with outcome after acute whiplash injury. MATERIALS AND METHODS: A systematic search for all systematic reviews on outcome prediction of acute whiplash injury was conducted across several electronic databases. The search was limited to publications in English, and there were no geographical or time of publication restrictions. Quality appraisal was conducted with A Measurement Tool to Assess Systematic Reviews. RESULTS: The initial search yielded 207 abstracts; of these, 195 were subsequently excluded by topic or method. Twelve systematic reviews with moderate quality were subsequently included in the analysis. Post-injury pain and disability, whiplash grades, cold hyperalgesia, post-injury anxiety, catastrophizing, compensation and legal factors, and early healthcare use were associated with continuation of pain and disability in patients with whiplash injury. Post-injury magnetic resonance imaging or radiographic findings, motor dysfunctions, or factors related to the collision were not associated with continuation of pain and disability in patients with whiplash injury. Evidence on demographic and three psychological factors and prior pain was conflicting, and there is a shortage of evidence related to the significance of genetic factors. CONCLUSIONS: This meta-review suggests an association between initial pain and anxiety and the outcome of acute whiplash injury, and less evidence for an association with physical factors. LEVEL OF EVIDENCE: Level 1. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10195-016-0431-x) contains supplementary material, which is available to authorized users.