High levels of sensitivity (94.0%, 82.3% and 82.3%) and specificity (81.45, 77.7% and 82.4%) were found in applying an upper limb Nordic-style questionnaire to two groups characterized by very different job physical demands in a longitudinal study by Descatha et al. Negative predictive values were calculated at 87.7, 64.5 and 96.9 while positive predictive values were determined to be 90.7, 89.9 and 40.8 among the study cohorts.
Study Design
Over a one year period, a “repetitive task” study recruited 1757 workers from five employment sectors: assembly-line manufacture of small electrical appliances; motor vehicle accessories, or ski accessories, packaging excluded; clothing or shoe industry, packaging excluded; food industry, packaging excluded; packaging (primarily in the food industry); and supermarket cashiers. Of all subjects, 76% were female and the mean age was 38.
Participants completed a 10 page upper limb Nordic-style questionnaire concerning symptoms over the prior six months. General inquires were followed by questions involving pain, treatment, and disorder impact for each upper limb anatomical region (shoulder, arm, elbow, forearm, wrist, and hand). The volunteers also completed a survey related to work conditions/exposures. A physician applied a standardized clinical examination on all participants.
Three years later, 598 of these same subjects completed the same upper limb Nordic-style questionnaire and a slightly shorter work exposure assessment. Again, a physician performed a clinical examination on all participants in the same manner as the baseline evaluation.
In a separate study, 2685 employees that were representative of the general workforce in the Pays de la Loire region of France participated in a similar research protocol. The mean age of this group was 38 while 42% were female. The volunteers completed a three page upper limb Nordic-style questionnaire involving work-related musculoskeletal symptoms experienced in the prior twelve months. Subjects also completed a twelve page survey that addressed work exposures, general data, and health information. The employee’s general physician performed a clinical exam similar to that conducted by physicians in the “repetitive task” study.
A positive finding in the upper limb Nordic-style questionnaire was defined as the reporting of at least one symptom in any region. A clinical examination positive finding was defined as a proven or suspected diagnostic case.
Other Findings
Those employees participating in the “repetitive task” survey had a high prevalence of diagnosed upper limb disorders (65% and 70% in the two cohorts). When restricted to the same diagnostic examination conclusions as the Pays de la Loire survey, the “repetitive task:” employees had a significantly higher prevalence of upper limb disorders than the Pays de la Loire employees (46% and 51% versus 13%).
Study Limitations
Reservations regarding the application of this research include:
- Although similar, each study used a different the upper limb Nordic-style questionnaire.
- Although similar, each study followed a different musculoskeletal diagnostic process.
- The authors felt there may have been bias in symptom reporting based on the sequencing of the surveys
Article Title: Validity of Nordic-style questionnaires in the surveillance of upper-limb work-related musculoskeletal disorders
Publication: Scandinavian Journal of Work, Environment & Health 33(1): 58-65, 2007
Authors: A Descatha, Y Roquelaure, J F Chastang, B Evanoff, M Melchior, C Mariot, C Ha, E Imbernon, M Goldberg, and A Leclerc
This article originally appeared in The Ergonomics Report™ on 2007-04-19.