Objectives: The aim of this cohort study was to investigate the association between self-reported cardiovascular disorders (CVD) and recovery from whiplash-associated disorder (WAD) after a traffic collision.
Materials and Methods: This study was based on the Saskatchewan Government Insurance cohort, including individuals over 18 years of age, who made a traffic-injury claim or received health care after a traffic injury, between 1997 and 1999. Participants completed a baseline questionnaire and were followed up by telephone interviews at 6 weeks, 3 months, 6 months, 9 months, and 12 months after injury. Our sample includes a subcohort of 6011 participants who reported WAD (defined as answering “yes” to the question “Did the accident cause neck or shoulder pain”) at baseline. The outcome, self-perceived recovery, was measured at all follow-up interviews. The presence of CVD and its effect on health was classified into 3 exposure categories: (1) CVD absent, (2) CVD present with no or mild effect on health, and (3) CVD present with moderate or severe effect on health. The association between CVD and recovery from WAD was assessed with Cox regression, and adjusted for potential confounders.
Results: We found a crude association between comorbid CVD with moderate or severe effect on health in women. However, the adjusted association was weak and potentially affected by residual confounding. We found no association in men.
Discussion: Our results suggest that CVD does not have an impact on the recovery of individuals with WAD.
*Institute of Environmental Medicine, Karolinska Institutet
**Scandinavian College of Naprapathic Manual Medicine, Stockholm, Sweden
†Canada Research Chair in Disability Prevention and Rehabilitation
‡UOIT-CMCC Centre for the Study of Disability Prevention and Rehabilitation, University of Ontario Institute of Technology (UOIT) Oshawa, Ontario
¶Division of Health Care and Outcomes Research, University Health Network, Toronto
#Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Toronto
§Department of Public Health Sciences and Alberta Centre for Injury Prevention and Research, University of Alberta, Edmonton, Edmonton, Canada
∥Institute of Sport Science and Clinical Biomechanics, Faculty of Health, University of Southern Denmark, Odense, Denmark
L.W.H. is employed at a private insurance company, Trygg Hansa, in Stockholm, Sweden, and received salary for consultancy at the Scandinavian College of Naprapathic Manual Medicine, Stockholm, Sweden. E.S. is employed at the Scandinavian College of Naprapathic Manual Medicine, Stockholm, Sweden, and has received a grant from AFA Insurance in the past. L.J.C. and J.D.C. previously received funding from Saskatchewan Government Insurance for the original data collection. L.J.C. currently has research grants from WCB Manitoba, CIHR and WCB Alberta, and received salary for consultancy at Alberta Government in the past. The remaining author declares no conflict of interest.
Reprints: Lina Palmlöf, MSc, Institutet för Miljömedicin, Karolinska Institutet, Box 20, Solna 177 71, Sweden (e-mail: firstname.lastname@example.org).
Received October 10, 2013
Received in revised form April 30, 2014
Accepted March 27, 2014