WASHINGTON – An association between a motor vehicle collision and the development of widespread body pain in some individuals was not supported by findings from an ongoing prospective study comparing two different cohorts.
However, the study of more than 8,000 people did suggest that such collisions may be associated with a post-crash onset of axial skeleton pain, John McBeth, Ph.D., reported at the annual meeting of the American College of Rheumatology.
“Physical stressors have been implicated in the onset of widespread pain disorders; particularly, whiplash experienced during a motor vehicle collision has been associated with the etiology of fibromyalgia,” said Dr. McBeth, senior lecturer in rheumatic disease epidemiology at the University of Manchester (England).
In the current study, a cohort of 1,499 patients aged 17–70 years who were involved in a motor vehicle collision (MVC) were compared with a control cohort of 6,792 individuals aged 25–65 years who participated in a pain survey.
Among patients who did not have widespread pain at baseline, 641 of 951 MVC patients and 3,058 of 3,780 control subjects participated in a 15-month follow-up. The rate of new-onset widespread pain in these subjects was similar between the MVC (8.4%) and control groups (11.6%). There also was no relationship between the severity of the collision and the development of widespread pain. These comparisons were adjusted for age, gender, pain at baseline, and psychological status. “This surprised us because we expected to see some kind of relationship between crash severity and the onset of widespread pain,” he said.
New-onset axial skeleton pain occurred at similar rates in the MVC (20%) and control cohorts (21%). But patients who had a severe collision were significantly more likely to report new-onset axial skeleton pain at the 15-month follow-up than were control patients.
This relationship persisted after adjustment for pain and psychological status at baseline.
The patients who developed axial skeleton pain may be “on the path” to developing widespread pain. With longer follow-up, the rate of new-onset widespread pain may be higher, Dr. McBeth said.
Previous studies have found that physical and psychosocial stressors are associated with an increased risk of new-onset widespread pain.
In one study of people who were in MVCs, the rate of new-onset fibromyalgia after the accident was significantly greater among those patients who had a cervical spine injury than it was in those patients who had leg fractures (Arthritis Rheum. 1997;40:446–52).
A case-control study found about 40% of fibromyalgia patients could recall a stressful event that may have precipitated the onset of their symptoms; these patients were most likely to report that a fracture, surgery, or workplace injury preceded the symptoms. Fibromyalgia patients were not more likely than controls to recall an MVC as a precipitating factor (Rheumatology [Oxford] 2002;41:450–3).
But an abstract presented at the annual meeting of the ACR in 2004 reported that among patients who had presented to an emergency department, the rate of new-onset fibromyalgia was significantly higher in those who had been in an MVC than in a control group of patients who had had a minor laceration. The MVC patients who reported neck pain at the time of presentation had the highest risk for developing fibromyalgia.
However, those studies did not take the role of psychological factors into account in relation to the onset of widespread body pain, Dr. McBeth said.
When he and his colleagues conducted a population-based, prospective study of 1,658 adults who did not have widespread pain at baseline, they found that individuals who reported high levels of somatic symptoms, illness behavior, psychological distress, and fatigue at baseline had a significantly increased risk of developing chronic widespread pain after 1 year (Arthritis Rheum. 2001;44:940–6).