In both science and media, the adverse effects of a long duration of computer use at work on musculoskeletal health have long been debated. Until recently, the duration of computer use was mainly measured by self-reports, and studies using more objective measures, such as software-recorded computer duration, were lacking. The objective of this study was to examine the association between duration of computer use at work, measured with software and self-reports, and the onset of severe arm–wrist–hand and neck–shoulder symptoms.
A 2-year follow-up study was conducted between 2004 and 2006 among 1951 office workers in The Netherlands. Self-reported computer duration and other risk factors were collected at baseline and at 1-year follow-up. Computer use at work was recorded continuously with computer software for 1009 participants. Outcome questionnaires were obtained at baseline and every 3 months during follow-up. Cases were identified based on the transition within 3 months of no or minor symptoms to severe symptoms.
Self-reported duration of computer use was positively associated with the onset of both arm–wrist–hand (RR 1.9, 95% CI 1.1 to 3.1 for more than 4 h/day of total computer use at work) and neck–shoulder symptoms (RR 1.5, 95% CI 1.1 to 2.0 for more than 4 h/day of mouse use at work). The recorded duration of computer use did not show any statistically significant association with the outcomes.
In the present study, no association was found between the software-recorded duration of computer use at work and the onset of severe arm–wrist–hand and neck–shoulder symptoms using an exposure window of 3 months. In contrast, a positive association was found between the self-reported duration of computer use at work and the onset of severe arm–wrist–hand and neck–shoulder symptoms. The different findings for recorded and self-reported computer duration could not be explained satisfactorily.