title: Injury Location and Mechanism for Complex Regional Pain Syndrome: A Nationwide Population-Based Case-Control Study in Taiwan.
abstract: BACKGROUND
  Few studies have investigated the relationship between injury location, mechanism and their association with complex regional pain syndrome (CRPS). We conducted a nationwide database survey to explore this issue.
  
  
  METHODS
  This was a population-based case-control study. Five hundred and eighty-nine patients with at least one ambulatory visit or admission with a principal diagnosis of CRPS from 2004 to 2009 were selected. For each CRPS patient, ten age- and sex-matched non-CRPS subjects were randomly selected. The odds ratios (PLoS One. 2013;8:e57205) and 95% confidence intervals (95% CIs) of risk factors for CRPS were derived from multivariate logistic regression models.
  
  
  RESULTS
  Injury was a risk factor for CRPS (OR, 2.96; 95% CI, 2.18 to 4.02) independent of age and sex. In adjusted models, open wound on the upper limbs (OR 1.25, 95% CI 1.02 to 1.54) conferred higher CRPS risk. Injury mechanisms including nerve and spinal cord injury (OR 2.42, 95% CI 1.44 to 4.08), muscle and joint sprain and strain (OR 1.69, 95% CI 1.40 to 2.03), superficial injury (OR 1.23, 95% CI 1.00 to 1.51), and contusion (OR 1.44, 95% CI 1.20 to 1.74), but not fracture, increased the risk of CRPS.
  
  
  CONCLUSIONS
  Injury in the extremities rather than the trunk is an important risk factor for CRPS. Certain injury mechanisms confer higher risk of CRPS. This nationwide study demonstrated that injury increased CRPS nearly threefold. Open wound, sprain and strain, superficial injury, contusion, and nerve and spinal cord injury are main injury mechanisms. Injury in the extremities confers a higher risk of CRPS.
authors.affiliation: Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Yi-Chia
authors.initials: YC
authors.lastname: Wang
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Hung-Yuan
authors.initials: HY
authors.lastname: Li
authors.affiliation: Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Feng-Sheng
authors.initials: FS
authors.lastname: Lin
authors.affiliation: Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Ya-Jung
authors.initials: YJ
authors.lastname: Cheng
authors.affiliation: Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Chi-Hsiang
authors.initials: CH
authors.lastname: Huang
authors.affiliation: Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Wei-Han
authors.initials: WH
authors.lastname: Chou
authors.affiliation: Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Hsing-Hao
authors.initials: HH
authors.lastname: Huang
authors.affiliation: Department of Family Medicine, China Medical University Hospital, Taichung, Taiwan.|School of Medicine, China Medical University, Taichung, Taiwan.|Department of Health Care Administration, Asian University, Taichung, Taiwan.
authors.forename: Cheng-Chieh
authors.initials: CC
authors.lastname: Lin
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Che-Chen
authors.initials: CC
authors.lastname: Lin
authors.affiliation: Institute of Environmental Health, China Medical University College of Public Health, Taichung, Taiwan.
authors.forename: Fung-Chang
authors.initials: FC
authors.lastname: Sung
authors.affiliation: Chia Nan University of Pharmacy and Science, Tainan, Taiwan.
authors.forename: Jung-Nan
authors.initials: JN
authors.lastname: Wei
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D020918:Complex Regional Pain Syndromes / Q000209:etiology*; D005121:Extremities / Q000293:injuries*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013624:Taiwan; D014947:Wounds and Injuries / Q000150:complications*
keywords: CRPS; complex regional pain syndrome; fracture; immobilization; injury; population-based case-control study; risk factors