Last Updated: 2007-12-05 13:52:14 -0400 (Reuters Health)

NEW YORK (Reuters Health) – A UK study finds that the prevalence of repetitive strain injury linked to the workplace appears to be exaggerated, a finding that calls into question the validity of information that European governments use to evaluate their occupational health strategies.

Statistics from Labour Force Surveys supposedly reflect the extent of work-related illness, Dr. Keith T. Palmer, at Southampton General Hospital, and colleagues explain in Occupational and Environmental Medicine, published online on December 4. They theorize that survey findings may not be reliable since they depend on respondents’ belief that their health problem is caused or exacerbated by their work.

To test their theory, they analyzed results of postal questionnaires, filled out by 1769 subjects who were currently employed. Subjects were asked about arm-straining occupational activity, mental health, self-rated health, and upper arm pain.

A total of 817 reported upper arm pain during the previous year; more than half (53.9%) considered their pain to be either caused or worsened by their work activities.

The researchers then calculated the population attributable fraction of arm injury resulting from arm-straining physical activity at work, based on data derived from the questionnaires and adjusted for potentially confounding risk factors.

"The estimated population attributable fraction for occupational exposure to arm-straining physical activities was 13.9%," Dr. Palmer’s group reports, "substantially less than the proportion of cases … who reported that their arm pain was caused or made worse by work (53.9%)."

For monitoring the incidence of work-related illness, they conclude, "controlled epidemiological investigations may estimate attributable numbers more reliably."

Occup Environ Med 2007.