title: Validity of a self-completed questionnaire measuring the physical demands of work.
abstract: OBJECTIVE
  This study determined the accuracy of workers in quantifying occupational physical demands on a self-administered questionnaire.
  
  
  METHODS
  First, a self-administered questionnaire on work postures, manual materials-handling, and repetitive upper-limb movements was validated using direct simultaneous observations for 123 randomly selected employees from 6 occupational settings. Second, weight estimation accuracy was assessed on visual analogue scales for 6 manual materials-handling activities using 20 randomly selected employees from 1 occupational setting.
  
  
  RESULTS
  At a dichotomous level (ever-never), the accuracy of most of the self-reported physical demands was good (sensitivity 60-100%; specificity 56-100%). A more-detailed analysis of the dimensions studied (frequency, duration and amplitude) also showed that the accuracy of the self-reported estimates was satisfactory. Full agreement between the estimated and observed frequency was >60% for most of the manual materials-handling activities. In addition the average difference between the estimated and observed duration of the physical demands was found to be small. Finally the average difference between the self-reported and actual weights of various loads was found to be modest.
  
  
  CONCLUSIONS
  The self-reported questionnaire used in this study would provide a useful instrument for estimating occupational physical demands and the frequency, duration, and amplitude of these demands in future epidemiologic studies associated with musculoskeletal pain.
authors.affiliation: Arthritis Research Campaign Epidemiology Research Unit, School of Epidemiology and Health Sciences, The University of Manchester, United Kingdom. Dan.Pope@fs1.ser.man.ac.uk
authors.forename: D P
authors.initials: DP
authors.lastname: Pope
authors.forename: A J
authors.initials: AJ
authors.lastname: Silman
authors.forename: N M
authors.initials: NM
authors.lastname: Cherry
authors.forename: C
authors.initials: C
authors.lastname: Pritchard
authors.forename: G J
authors.initials: GJ
authors.lastname: Macfarlane
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D016552:Ergometry; D005260:Female; D006801:Humans; D017770:Lifting; D008297:Male; D015588:Observer Variation; D009790:Occupations; D010147:Pain Measurement; D005082:Physical Exertion; D011897:Random Allocation; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D006113:United Kingdom; D016526:Workload