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

Scand J Work Environ Health. 2001 Feb;27(1):41-8. doi: 10.5271/sjweh.585.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Cohort Studies
  • Female
  • Humans
  • Linear Models
  • Male
  • Neck Pain / epidemiology*
  • Occupational Exposure / adverse effects*
  • Pain Measurement
  • Patient Compliance
  • Predictive Value of Tests
  • Prospective Studies
  • Reproducibility of Results
  • Risk Assessment
  • Risk Factors
  • Severity of Illness Index
  • Shoulder Pain / epidemiology*
  • Surveys and Questionnaires
  • Sweden / epidemiology
  • Workload*