title: Deep venous thrombosis associated with corporate air travel.
abstract: BACKGROUND
  Deep venous thrombosis (DVT) is commonly seen among bedridden and postoperative patients. Its association with travel may also make DVT an occupational health risk to otherwise healthy business travelers. We estimated the incidence of and risk factors for DVT among 8,189 World Bank employees and a subset of 4,951 international business travelers.
  
  
  METHODS
  Occurrence of DVT between 1995 and 1998 was determined using 1) medical insurance claims; 2) Workers' Compensation claims; and 3) intra-office E-mail solicitation followed by interview. For each insurance claim case, 10 controls were randomly selected from among World Bank employees insured during the same month and year as the case's claim was filed, and case-control analyses were performed to identify potential predictors or risk factors for DVT.
  
  
  RESULTS
  Thirty individuals filed claims for DVT of the legs (annual incidence rate: 0.9 per 1,000 employees); three of these claims were filed within 30 days after a travel mission. Two employees reported DVT as a Workers' Compensation injury, and five staff with verified DVT participated in interviews. After controlling for age and gender, no association with any travel-related covariate was seen. Results of analyses considering all thrombophlebitis and thromboembolism followed the same pattern. The average annual incidence of DVT occurring within 30 days of mission among traveling staff ranged from 0.10 per 1,000 to 0.25 per 1,000 travelers, depending on the case-finding method.
  
  
  CONCLUSIONS
  No association between DVT and travel was observed after adjustment for gender and age. These results, however, are preliminary, and due to the rarity of DVT, based on small numbers.
authors.affiliation: Health Services Department, the World Bank, Washington, District of Columbia 20433, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Dimberg
authors.forename: K A
authors.initials: KA
authors.lastname: Mundt
authors.forename: S I
authors.initials: SI
authors.lastname: Sulsky
authors.forename: B H
authors.initials: BH
authors.lastname: Liese
mesh_terms: D000328:Adult; D000368:Aged; D000401:Aircraft; D016022:Case-Control Studies; D015331:Cohort Studies; D004219:District of Columbia / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D007345:Insurance Claim Review; D016015:Logistic Models; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D016272:Occupational Health; D012189:Retrospective Studies; D012307:Risk Factors; D014195:Travel; D020246:Venous Thrombosis / Q000453:epidemiology* / Q000209:etiology*