Risk factors for neck and shoulder disorders: a nested case-control study covering a 24-year period.

BACKGROUND

In 1969 a population-based study was conducted in the Stockholm region. From the 2,579 randomly selected participants (18-65 years of age in 1969), the youngest subset were asked to participate in a reexamination in 1993. Information regarding working conditions, conditions outside work, and neck and shoulder disorders was collected retrospectively for the period 1970-1993.

METHODS

Of 783 eligible subjects (42-59 years of age in 1993), 484 responded. Cases of neck/shoulder disorders were defined by past sick leave or medical attention or recent symptoms, depending on available information. For each case (n = 271) two controls were randomly selected, matched by age and gender. Variables regarding both physical and psychosocial conditions were included in the matched analyses.

RESULTS

Among women mainly psychosocial factors and among men mainly physical factors were associated with neck/shoulder disorders. The only gender common risk indicator found was repetitive hand work (OR approximately 1.5). Interactive effects were also observed.

CONCLUSIONS

The impact on neck/shoulder disorders from separate factors was moderate but combinations of physical and psychosocial factors, as well as of work-related and non-work-related factors, produced relative risks above 2.