A 1-year prospective study of risk factors

Article abstract—Background: Exposure to a whiplash injury implies a risk for development of chronic disability and handicap, with reported frequencies ranging from 0% to 50% in follow-up studies. The exact risk for development of chronic whiplash syndrome is not known. Objective: To prospectively determine the sensitivity and specificity of five possible predictors for handicap following a whiplash injury. Methods: In a 1-year prospective study of persons with acute whiplash injury (n 5 141) and control subjects who had acute ankle distortion (n 5 40), pain intensity, number of nonpainful neurologic complaints, cervical mobility, workload during extension and flexion of the neck, and results of psychometric assessment were recorded. The consecutively sampled injured persons were assessed with structured and semistructured questionnaires, and underwent neurologic examination after 1 week and 1, 3, 6, and 12 months. After 3 to 4 years, participants with whiplash injury were questioned about legal issues. Results: After 1 year, 11 (7.8%) persons with whiplash injury had not returned to usual level of activity or work. The best single estimator of handicap was the cervical range-of-motion test, which had a sensitivity of 73% and a specificity of 91% (p , 0.01, Cox regression analysis). Accuracy and specificity increased to 94% and 99% when combined with pain intensity and other complaints. This increase was gained at the expense of a reduced sensitivity. Initiation of lawsuit within first month after injury did not influence recovery. Conclusion: The cervical range-of-motion test has a high sensitivity in prediction of handicap after acute whiplash injury. The value of cervical range-of-motion test is further improved by additional recording of symptoms and pain intensity.