Acute emotional response to common whiplash predicts subsequent pain complaints: A prospective study of 107 subjects sustaining whiplash injury

Previous studies claiming that psychosocial factors do not primarily influence the course of recovery from common whiplash have all been conducted on patient groups referred by medical physicians because of acute symptoms days to weeks after the injury. These designs may falsely underestimate the role of psychosocial predictors in the course of common whiplash. We studied 107 subjects consecutively admitted to the Municipality of Oslo Emergency Service hours after sustaining a whiplash injury. Acute assessment included clinical examination, a questionnaire about preaccident health problems, assessment of acute emotional response to the injury (Impact of Event Scale (IES)), and visual analogue scale (VAS) assessment of the acute pain. Four weeks after the injury 93% of the subjects filled in a questionnaire about their symptoms including VAS-rated neck pain. A significant correlation between acute VAS neck pain and IES scores were found. At 4 weeks 42% of the subjects still reported significant pain problems. Seventy per cent of these subjects had high IES scores acutely, compared with only 26% in the low-pain group (p>0.0001). Neither the presence of neck pain acutely nor neck stiffness, headache, interscapular pain, and difference in speed between the patients car and the assaulting car predicted symptoms 1 month after injury. This is the first study assessing patients hours after whiplash injury. Our findings indicate that the acute psychologic responses to a whiplash incident is the strongest predictor of maintenance of pain symptoms 4 weeks later. This finding seriously questions some authors' assumptions that psychosocial factors do not primarily influence the course of recovery from common whiplash.