title: Widespread pain following whiplash-associated disorders: incidence, course, and risk factors.
abstract: OBJECTIVE
  To investigate the incidence and course of widespread pain (WP) subsequent to localized pain in subjects with whiplash-associated disorders (WAD); and to investigate the influence of depressive symptoms, neck pain intensity, number of whiplash-associated symptoms, and number of painful body areas on such conditions.
  
  
  METHODS
  From a large prospective cohort of injury claimants who reported WAD after motor vehicle collision (MVC; n = 7462), we identified a subgroup with only localized head/neck/back pain, and who responded to one or more followup questionnaires mailed at 6 weeks and 4, 6, and 12 months after the MVC (n = 266). Pain drawings were distributed at the followup, and we defined WP as having 9 or more painful areas, including posterior neck, at any of these occasions. Depressive symptoms were assessed with the Center for Epidemiological Studies Depression Scale and pain intensity with on a visual analog scale (VAS).
  
  
  RESULTS
  The cumulative incidence of WP was 21%, and it occurred early after the injury. Continuous WP over the 12 months was rare. The odds for developing WP were greater in those with depressive symptoms (OR 3.2, 95% CI 1.6-6.3), VAS pain intensity 55-100 (OR 3.2, 95% CI 1.3-8.0), reporting > or = 3 pain-associated symptoms (OR 1.9, 95% CI 0.9-3.8), and those reporting 4 or 5 painful body areas (OR 2.6, 95% CI 1.3-5.4).
  
  
  CONCLUSIONS
  WP occurred early in the course. Even though the cumulative incidence was 21%, continuous WP was rare. Subjects with WAD who report early depressive symptoms and more severe neck injury symptoms are at risk of developing WP after MVC.
authors.affiliation: Institute of Environmental Medicine, Division of Epidemiology, Karolinska Institutet, Stockholm, Sweden. Lena.Holm@ki.se
authors.forename: Lena W
authors.initials: LW
authors.lastname: Holm
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Carroll
authors.forename: J David
authors.initials: JD
authors.lastname: Cassidy
authors.forename: Eva
authors.initials: E
authors.lastname: Skillgate
authors.forename: Anders
authors.initials: A
authors.lastname: Ahlbom
mesh_terms: D000063:Accidents, Traffic; D000293:Adolescent; D000328:Adult; D001416:Back Pain / Q000209:etiology; D015331:Cohort Studies; D003863:Depression / Q000209:etiology; D005260:Female; D006261:Headache / Q000209:etiology; D006801:Humans; D015994:Incidence; D008297:Male; D019547:Neck Pain / Q000209:etiology* / Q000523:psychology; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D014911:Whiplash Injuries / Q000150:complications* / Q000453:epidemiology* / Q000523:psychology