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Cognitive determinants of pain and disability in patients with chronic whiplash-associated disorder: a cross-sectional observational study
Physiotherapy 96 (2010) 350–351
Letters to the Editor
Cognitive determinants of pain and disability in patients with chronic whiplash-associated disorder: a crosssectional observational study Dear Editor I read with interest the research on cognitive determinants of pain and disability by Thompson et al. [1], but was somewhat perplexed by their opening sentence, which stated, ‘involvement in a motor vehicle collision has been shown to be a significant factor for the development of persistent neck pain’ [2]. Unfortunately, the authors appear to have misquoted the conclusions of Croft et al. [2], and I fear that in so doing may have inadvertently opened up the wounds of an antique whiplash controversy: does being in a motor vehicle collision lead to long-term neck problems? In a prospective study, Croft et al. [2] demonstrated that a history of injury to the neck was an independent and distinct risk factor for the development of subsequent neck pain. They stated that their study was ‘limited in extrapolating to the type or nature of the injury, and injury in this study cannot be assumed to be equivalent to road traffic-related whiplash injury’. Clearly, one cannot infer from this data that the injuries described arose solely as a result of motor vehicle collisions. So, is being in a motor vehicle collision a risk factor for neck pain? It would appear not and this has been demonstrated in a high-quality epidemiological study [3]. The reason for this is simple and it is an important point: not all occupants of motor vehicles that are involved in collisions are injured. In their study, Berglund et al. [3] divided drivers exposed to a rear-end collision into two subgroups: those without reported whiplash injury (n = 204) and those with reported whiplash injury (n = 232). Two comparison groups unexposed to motor vehicle collisions were selected. The authors concluded that the relative risk for neck pain in subjects with whiplash injury was 2.7 (95% confidence interval 2.1 to 3.5). The corresponding relative risk for those exposed to a motor vehicle collision but who were not injured was 1.3 (95% confidence interval 0.8 to 2.0). Indeed, the prevalence of neck pain was 11% and 15% in the two groups who were not exposed to a motor
vehicle collision, and 14% in the group who were exposed but who did not develop an injury. In contrast, the prevalence in those who were exposed and who did develop a whiplash injury was 40%. Thus, involvement in a motor vehicle collision is clearly not a significant factor for the development of persistent neck pain. However, an occupant who develops symptoms after being involved in a motor vehicle collision does have an increased risk of suffering chronic neck pain.
References [1] Thompson DP, Oldham JA, Urmston M, Woby SR. Cognitive determinants of pain and disability in patients with chronic whiplashassociated disorder: a cross-sectional observational study. Physiotherapy 2010;96:151–9. [2] Croft PR, Lewis M, Papgeorgiou AC, Thomas E, Jayson MIV, Macfarlane GJ, et al. Risk factors for neck pain: a longitudinal study in the general population. Pain 2001;93:317–25. [3] Berglund A, Alfredsson I, Cassidy JD, Jensen I, Nygren A. The association between exposure to a rear-end collision and future neck and shoulder pain: a cohort study. J Clin Epidemiol 2000;35: 1089–94.
Chris Worsfold Kent Whiplash & Neck Pain Centre, The Tonbridge Clinic, 339 Shipbourne Road, Tonbridge, Kent, UK E-mail address: [email protected] doi:10.1016/j.physio.2010.07.001
Authors’ response We would like to thank Mr Worsfold for his comments [1] about our recent publication in Physiotherapy [2], and thank the Editor for the opportunity to address these comments. We acknowledge that Croft et al. [3] refer to neck injury rather than whiplash per se. However, as Croft et al. discussed, it was likely that motor vehicle collisions were amongst the causes of neck injury encompassed in their study. Moreover, a number of other studies have reported that the
0031-9406/$ – see front matter © 2010 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.
Letters to the Editor
Cognitive determinants of pain and disability in patients with chronic whiplash-associated disorder: a crosssectional observational study Dear Editor I read with interest the research on cognitive determinants of pain and disability by Thompson et al. [1], but was somewhat perplexed by their opening sentence, which stated, ‘involvement in a motor vehicle collision has been shown to be a significant factor for the development of persistent neck pain’ [2]. Unfortunately, the authors appear to have misquoted the conclusions of Croft et al. [2], and I fear that in so doing may have inadvertently opened up the wounds of an antique whiplash controversy: does being in a motor vehicle collision lead to long-term neck problems? In a prospective study, Croft et al. [2] demonstrated that a history of injury to the neck was an independent and distinct risk factor for the development of subsequent neck pain. They stated that their study was ‘limited in extrapolating to the type or nature of the injury, and injury in this study cannot be assumed to be equivalent to road traffic-related whiplash injury’. Clearly, one cannot infer from this data that the injuries described arose solely as a result of motor vehicle collisions. So, is being in a motor vehicle collision a risk factor for neck pain? It would appear not and this has been demonstrated in a high-quality epidemiological study [3]. The reason for this is simple and it is an important point: not all occupants of motor vehicles that are involved in collisions are injured. In their study, Berglund et al. [3] divided drivers exposed to a rear-end collision into two subgroups: those without reported whiplash injury (n = 204) and those with reported whiplash injury (n = 232). Two comparison groups unexposed to motor vehicle collisions were selected. The authors concluded that the relative risk for neck pain in subjects with whiplash injury was 2.7 (95% confidence interval 2.1 to 3.5). The corresponding relative risk for those exposed to a motor vehicle collision but who were not injured was 1.3 (95% confidence interval 0.8 to 2.0). Indeed, the prevalence of neck pain was 11% and 15% in the two groups who were not exposed to a motor
vehicle collision, and 14% in the group who were exposed but who did not develop an injury. In contrast, the prevalence in those who were exposed and who did develop a whiplash injury was 40%. Thus, involvement in a motor vehicle collision is clearly not a significant factor for the development of persistent neck pain. However, an occupant who develops symptoms after being involved in a motor vehicle collision does have an increased risk of suffering chronic neck pain.
References [1] Thompson DP, Oldham JA, Urmston M, Woby SR. Cognitive determinants of pain and disability in patients with chronic whiplashassociated disorder: a cross-sectional observational study. Physiotherapy 2010;96:151–9. [2] Croft PR, Lewis M, Papgeorgiou AC, Thomas E, Jayson MIV, Macfarlane GJ, et al. Risk factors for neck pain: a longitudinal study in the general population. Pain 2001;93:317–25. [3] Berglund A, Alfredsson I, Cassidy JD, Jensen I, Nygren A. The association between exposure to a rear-end collision and future neck and shoulder pain: a cohort study. J Clin Epidemiol 2000;35: 1089–94.
Chris Worsfold Kent Whiplash & Neck Pain Centre, The Tonbridge Clinic, 339 Shipbourne Road, Tonbridge, Kent, UK E-mail address: [email protected] doi:10.1016/j.physio.2010.07.001
Authors’ response We would like to thank Mr Worsfold for his comments [1] about our recent publication in Physiotherapy [2], and thank the Editor for the opportunity to address these comments. We acknowledge that Croft et al. [3] refer to neck injury rather than whiplash per se. However, as Croft et al. discussed, it was likely that motor vehicle collisions were amongst the causes of neck injury encompassed in their study. Moreover, a number of other studies have reported that the
0031-9406/$ – see front matter © 2010 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.