title: Venous thromboembolism risk associated with protracted work- and computer-related seated immobility: A case-control study.
abstract: OBJECTIVE
  To examine the association between venous thromboembolism and prolonged work- and computer-related seated immobility.
  
  
  METHODS
  A case-control study.
  
  
  METHODS
  Cases were 200 patients attending venous thromboembolism clinics with a history of deep vein thrombosis and/or pulmonary embolism in the past six months, and controls were 200 patients treated in fracture clinic for an upper limb injury in the past six months.
  
  
  METHODS
  Logistic regression was used to estimate the association between venous thromboembolism and prolonged work- and computer-related seated immobility in the 28 days before the index event. Prolonged work- and computer-related seated immobility was defined firstly as a categorical variable with at least 10 h seated in a 24-h period, including at least 2 h without getting up; and secondly as the actual time spent seated in a 24-h period.
  
  
  RESULTS
  Prolonged work- and computer-related seated immobility (categorical variable) was present in 36 (18%) cases and 31 (15.5%) controls. In multivariate analysis, there was no significant association between prolonged seated immobility and venous thromboembolism, odds ratio 1.18 (95% CI 0.56 to 2.48), P = 0.67. For the mean and maximum number of hours seated in a 24-h period, the odds ratios for the association per additional hour seated with venous thromboembolism were 1.08 (95% CI 1.01 to 1.6), P = 0.02 and 1.04 (95% CI 0.99 to 1.09), P = 0.08, respectively.
  
  
  CONCLUSIONS
  This study found a weak association between venous thromboembolism and prolonged work- and computer-related seated immobility, with increasing mean hours seated associated with a higher risk of venous thromboembolism.
authors.affiliation: Medical Research Institute of New Zealand, Wellington 6242, New Zealand; Capital and Coast District Health Board, Wellington 6021, New Zealand.
authors.forename: Irene
authors.initials: I
authors.lastname: Braithwaite
authors.affiliation: Medical Research Institute of New Zealand, Wellington 6242, New Zealand.
authors.forename: Bridget
authors.initials: B
authors.lastname: Healy
authors.affiliation: Medical Research Institute of New Zealand, Wellington 6242, New Zealand; Capital and Coast District Health Board, Wellington 6021, New Zealand.
authors.forename: Laird
authors.initials: L
authors.lastname: Cameron
authors.affiliation: University of Otago, Wellington 6021, New Zealand.
authors.forename: Mark
authors.initials: M
authors.lastname: Weatherall
authors.affiliation: Medical Research Institute of New Zealand, Wellington 6242, New Zealand; Capital and Coast District Health Board, Wellington 6021, New Zealand.
authors.forename: Richard
authors.initials: R
authors.lastname: Beasley
keywords: computer; immobility; venous thromboembolism