The reason why some individuals develop chronic symptoms, whiplash-associated disorder, following whiplash trauma is poorly understood. We explored whether precollision pain-related diagnoses, medically unexplained symptoms, and psychiatric diagnoses are related to whiplash-associated disorder.
A cohort of 719 individuals exposed to whiplash trauma and subsequently experiencing symptoms within 72 hours (whiplash-exposed cohort) and 3595 matched controls were included in this observational prospective study. At 12 months postcollision, the whiplash-exposed cohort rated their neck pain using the Visual Analog Scale. Data on health were obtained from the Danish National Patient Register for the whiplash-exposed cohort and for the controls for a 5-year period before collision.
The whiplash-exposed cohort had significantly increased incidences of precollision pain-related diagnoses: χ2(1)=17.42, P<0.001 and medically unexplained symptoms: χ2(1)=22.22, P<0.001 but not psychiatric diagnoses: χ2(1)=3.60, P>0.05 compared with controls in the 5-year period. Participants from the whiplash-exposed cohort with precollision pain-related diagnoses (odds ratio=2.46; 95% confidence interval, 1.39; 4.35) and medically unexplained symptoms (odds ratio, 1.72; 95% confidence interval, 1.04; 2.84) had significantly increased odds for neck pain at follow-up.
Precollision pain and medically unexplained symptoms predict chronic neck pain following whiplash trauma. This may indicate that a sensitization process was initiated before the collision or that individuals with precollision low threshold for contacting health care services maintain this behavior postcollision. The collision may trigger existing individual vulnerabilities that constitute to be a risk factor for chronic whiplash.
*The Research Clinic for Functional Disorders and Psychosomatics, Aarhus University Hospital
§Department of Clinical Medicine, The Danish Pain Research Center, Aarhus C
†Department of Neurology, Spinal Cord Injury Centre of Western Denmark, Regional Hospital of Viborg, Viborg
‡Center for Rheumatology and Spine Diseases, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Glostrup, Denmark
This study was supported by the Trade Organization of Insurance and Pensions in Denmark (DK-2900 Hellerup), The Health Insurance Foundation (DK-1571 Copenhagen V), The Research Foundation of Aarhus University (DK-8200 Aarhus N), The Tryg Foundation (DK-2830 Virum), The Illum Foundation (DK-1152 Copenhagen K), The Lippmann Foundation (DK-1271 Copenhagen K), The Foundation of The Family Hede Nielsen (DK-8700 Horsens), and The Danish Rheumatism Association (DK-2820 Gentofte). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. No information about results or participation in the project was given to the participants' insurance company. The authors declare no conflict of interest.
Reprints: Tina B.W. Carstensen, PhD, The Research Clinic for Functional Disorders and Psychosomatics, Aarhus University Hospital, Noerrebrogade 44, building 4, 8000 Aarhus C, Denmark (e-mail: firstname.lastname@example.org).
Received May 31, 2018
Received in revised form October 17, 2018
Accepted December 11, 2018