Study design: Empirical studies concerning the whiplash syndrome are reviewed from the point of view of epidemiologic methodology.
Objective: To assess the nosologic status of the whiplash syndrome.
Summary of background data: Although a large number of studies concerning the syndrome exist, there is still controversy concerning the existence of the syndrome.
Methods: The manner in which each study contributes to the validity of the syndrome is determined on the basis of the methodologic design (descriptive, case-control, cohort, and intervention/experimental) of the study.
Results: Whereas the face validity of the syndrome is excellent, the descriptive, construct, and predictive validity are rather poor. In particular, convincing empirical evidence for a causal link (construct validity) between the trauma mechanism and chronic symptoms is sparse.
Conclusions: Carefully conducted studies designed to assess the degree to which head and nec trauma contribute to the development of chronic pain, particularly head and neck pain, are urgently needed.