The importance of variations in questionnaire administration.

A standardised Nordic questionnaire for the analysis of musculoskeletal symptoms was administered to Swedish bus drivers and shunters in two different ways. The first was a cohort study in which all questions were focused on musculoskeletal troubles, whilst the other was the administration of the standardised questionnaire during a general health examination. Higher frequencies of musculoskeletal troubles were reported in the cohort study. When this type of questionnaire was administered prior to the general health examination, no differences were seen, which may be an effect of focusing first on the musculoskeletal symptoms. It can thus be concluded that it is important, not only to use standardised questionnaires, but also to consider the way the questionnaire is administered when comparing the results from different studies.