Original article

Scand J Work Environ Health 2001;27(1):41-48    pdf

doi:10.5271/sjweh.585

Questionnaire-based mechanical exposure indices for large population studies - reliability, internal consistency and predictive validity

by Balogh I, Ørbaek P, Winkel J, Nordander C, Ohlsson K, Ektor-Andersen J; Malmö Shoulder-Neck Study Group

Objectives This study attempts to construct valid indices for mechanical exposure of the shoulder-neck region with relation to the development of shoulder-neck pain in a 1-year perspective study of a general population.

Methods A comprehensive questionnaire was presented to 14 556 subjects aged 45 or 65 years and repeated after 12 months. Twenty-four questions concerning positions, movements, and manual materials handling were registered on a 3-point impact scale. Musculoskeletal problems were reported on a slightly modified version of the Standardized Nordic Questionnaire for the Analysis of Musculoskeletal Symptoms. Test-retest stability after 2 weeks was calculated for 232 consecutive participants. Based on mechanistic theories, 4 exposure indices were formed. Another 5 constructs were obtained by factor analysis.

Results All the indices showed good test-retest stability, and 5 of them had very good internal consistency. Due to overlaps between the indices, 2 indices stood out as having unique properties. One of them concerned mainly postures and the other dealt primarily with measured lifting. However, the latter was not related to the shoulder-neck pain outcome when adjusted for the posture index. The posture index showed an exposure-effect relationship with the outcome. The job titles implied a large degree of exposure misclassification.

Conclusions The posture index is recommended as a mechanical exposure index for analyses of interaction with other possible determinants of shoulder-neck pain (ie, psychosocial factors). The use of such an index instead of job titles in large population studies will reduce the risk of misclassification.

This article refers to the following texts of the Journal: 1999;25(2):105-114  1999;25(1):57-66  1999;25(2):81-83
The following articles refer to this text: 2009;35(2):113-126; 2013;39(4):390-400; 2014;40(6):597-609