Methodological limitations in the study of video display terminal use and upper extremity musculoskeletal disorders

✍ Scribed by Fredric Gerr; Michele Marcus; Daniel J. Ortiz

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 560 KB
• Volume: 29
• Category: Article
• ISSN: 0271-3586
• DOI: 10.1002/(sici)1097-0274(199606)29:6<649::aid-ajim9>3.0.co;2-e

✦ Synopsis

Upper extremity musculoskeletul disorders may occur as a result of work with keyboardequipped video display terminals. Many studies of the associations between keyboard use and upper extremity disorders have appeared in both the human factors and occupationul epidemiologic literature. Methodological limitations and inconsistent results have limited conclusions that cun be made from these studies, however. Although exposure conditions can be carefully c.ontrolled, human factors studies are limited by relatively small sample sizes, short e.rposure durations, and reliance on outcome measures with unknown relevance to chronic adverse health effects. Epidemiologic studies have been limited by poor ascertainment of both exposure and health outcome. Many have ,failed to control for any potential confounding. An almost exclusilve reliance on cross-sectional study designs has resulted in possible bias from selective survild, exposure-effect reversal, and poor estimates of exposiires occurring prior to development of the disorder. Given the inconsistency in the literature arid the growing controversy ~urroitnding this issue, prospective study of this question using objective methods for assessment of exposure and health outcome is recommended. This design allows identi'jication of incident ca.se.s and minimices bias from selective survival. In addition, ergonomic and psychosocial variables prior to onset of symptom can be ascertained periodically. Given estimates.for up to 100 million video display terminals to be in use in the United States by the year 2000, clarificatiori of the health effects of their use is critical.