Journal of Clinical Epidemiology 54 (2001) 851–856 0895-4356/01/$ – see front matter © 2001 Elsevier Science Inc. All rights reserved. PII: S0895-4356(00)00369-3 The association between exposure to a rear-end collision and future health complaints Anita Berglund a, *, Lars Alfredsson b , Irene Jensen a , J. David Cassidy a,c , Åke Nygren a a Department of Clinical Neuroscience, Karolinska Institutet, Box 12718, SE-112 94 Stockholm, Sweden b Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden c Department of Public Health Sciences, University of Alberta, Canada Received 16 March 2000; received in revised form 8 November 2000; accepted 4 December 2000 Abstract Different symptoms, together with neck pain, have been attributed to persons with persistent complaints after a previous motor vehi- cle crash (MVC) and are sometimes referred to as the “late whiplash syndrome.” A cohort study was conducted to determine whether ex- posure to a rear-end collision, with or without whiplash injury, is associated with future health complaints. The results regarding future neck or shoulder pain have previously been described, and the objective of the present report was to focus on outcomes other than neck pain. Included in the study were persons 18 to 65 years of age and covered by traffic insurance at one of the largest insurance companies in Sweden. Claim reports were collected from the period November 1987 to April 1988. Drivers exposed to a rear-end collision were di- vided into two subgroups: those with reported whiplash injury (n = 232) and those without reported whiplash injury (n = 204). For com- parison, 3688 subjects who were unexposed to MVCs were selected, with consideration taken to the age and gender distribution in the ex- posed subgroups. The prevalence of different health complaints among the study subjects was estimated according to a mailed questionnaire at follow-up in 1994, 7 years after the rear-end collision. When exposed subjects with whiplash injury were compared to un- exposed subjects, increased relative risks in the range of 1.6–3.7 were seen for headache, thoracic and low back pain, as well as for fatigue, sleep disturbances and ill health. No corresponding increased risks were found among the exposed subjects without reported whiplash in- jury. We conclude that rear-end collisions resulting in reported whiplash injuries seem to have a substantial impact on health complaints, even a long time after the collision. There is a need to identify factors that predict a non-favorable outcome in order to improve clinical management. © 2001 Elsevier Science Inc. All rights reserved. Keywords: Epidemiology; Cohort studies; Traffic accidents; Whiplash injuries; Headache; Back pain 1. Introduction Soft-tissue injuries of the cervical spine, generally named whiplash injuries, are a common result of motor ve- hicle crashes (MVCs). Objective findings are commonly not present and the diagnosis is then often based on subjective complaints. In addition to neck pain, which is the most fre- quently reported initial feature due to whiplash injury, vari- ous other symptoms may also be present [1]. Headache has been mentioned as being a frequent acute symptom, and other complaints such as back pain, fatigue and sleep distur- bances have been reported in different magnitudes in con- nection with MVCs [2–4]. The figures published on the prognosis after a whiplash injury vary remarkable [3,5–7]. It is even questioned whether the injury can cause chronic symptoms [8–10]. In follow-up studies, persistent health complaints such as neck pain, headache, fatigue and other symptoms have been described [1]. A collection of concom- itant persistent symptoms is sometimes referred to as the “late whiplash syndrome,” originally described by Balla [11]. Although commonly discussed there is no precise def- inition [10], but it is suggested that neck pain, headache and depression are symptoms that should be included. Different health complaints are also frequently reported in the general population [12], and consequently it is necessary to include an unexposed comparison group when assessing persistent complaints after an MVC. Such a design was used in the present cohort study and the results regarding future neck or shoulder pain have previously been reported [13]. The objective of the present report was to determine whether exposure to a rear-end collision, with or without whiplash injury, is associated with future health complaints, besides neck pain. * Corresponding author. Tel.: +46-8-6922259; fax: +46-8-6539413. E-mail address: anita.berglund@cns.ki.se (A. Berglund)