title: Data processing costs for three posture assessment methods.
abstract: BACKGROUND
  Data processing contributes a non-trivial proportion to total research costs, but documentation of these costs is rare. This paper employed a priori cost tracking for three posture assessment methods (self-report, observation of video, and inclinometry), developed a model describing the fixed and variable cost components, and simulated additional study scenarios to demonstrate the utility of the model.
  
  
  METHODS
  Trunk and shoulder postures of aircraft baggage handlers were assessed for 80 working days using all three methods. A model was developed to estimate data processing phase costs, including fixed and variable components related to study planning and administration, custom software development, training of analysts, and processing time.
  
  
  RESULTS
  Observation of video was the most costly data processing method with total cost of € 30,630, and was 1.2-fold more costly than inclinometry (€ 26,255), and 2.5-fold more costly than self-reported data (€ 12,491). Simulated scenarios showed altering design strategy could substantially impact processing costs. This was shown for both fixed parameters, such as software development and training costs, and variable parameters, such as the number of work-shift files processed, as well as the sampling frequency for video observation. When data collection and data processing costs were combined, the cost difference between video and inclinometer methods was reduced to 7%; simulated data showed this difference could be diminished and, even, reversed at larger study sample sizes. Self-report remained substantially less costly under all design strategies, but produced alternate exposure metrics.
  
  
  CONCLUSIONS
  These findings build on the previously published data collection phase cost model by reporting costs for post-collection data processing of the same data set. Together, these models permit empirically based study planning and identification of cost-efficient study designs.
authors.affiliation: Centre for Musculoskeletal Research, Department of Occupational and Public Health Sciences, University of Gävle, SE - 801 76 Gävle, Sweden. catherine.trask@usask.ca.
authors.forename: Catherine
authors.initials: C
authors.lastname: Trask
authors.forename: Svend Erik
authors.initials: SE
authors.lastname: Mathiassen
authors.forename: Jennie
authors.initials: J
authors.lastname: Jackson
authors.forename: Jens
authors.initials: J
authors.lastname: Wahlström
mesh_terms: D035843:Biomedical Research / Q000191:economics*; D003198:Computer Simulation; D019937:Diagnostic Techniques and Procedures / Q000191:economics; D006801:Humans; D064887:Observational Studies as Topic; D060051:Occupational Injuries / Q000175:diagnosis / Q000517:prevention & control; D011187:Posture; D057566:Self Report / Q000191:economics; D012782:Shoulder / Q000473:pathology; D013223:Statistics as Topic / Q000191:economics*; D060726:Torso / Q000473:pathology; D014741:Video Recording