8223288 Job exposure matrix on the incidence of carpal tunnel release surgery in the CONSTANCES cohort

<h3>Background</h3> Most studies of Carpal Tunnel Syndrome have examined only current workplace exposures as risk factors. We examined the effects of both recent and past work exposures on the incidence of surgery for carpal tunnel release (CTR). <h3>Material and Methods</h3> Participants in a large prospective study (CONSTANCES) were surveyed. The survey included self-reported history of current and past jobs, allowing estimation of past and current workplace physical exposures using an existing job exposure matrix (JEM). CTR cases were ascertained through matching the surveys to national health insurance data. Poisson regression analyses (controlling for age, Body Mass Index, and sex) computed the relative risks (RR) of future CTR associated with different work exposures. Eleven exposures including physical force, repetition, posture, and keyboard use were categorized into quartiles. Models included different time periods of exposure and/or different exposure lag times. <h3>Results</h3> 777 cases of CTR were observed among the 56,289 person cohort. RR of CTR per 5 years of exposure in the upper quartile included 1.19[1.13-1.25] for pressing with the base of the hand, 1.17[1.12-1.23] for use of vibrating tools, 1.17[1.12-1.22] for rotation of the forearm, and 0.88[0.84-0.91] for keyboard use. Higher effect sizes were seen among current workers than among those who had not worked in 5 or more years. Lagging exposures by 3 and 5 years reduced the strengths of association. <h3>Discussion</h3> Use of a JEM in a large general population cohort allowed us to study the effects of both recent and past work exposures on the incidence of carpal tunnel syndrome. While more recent exposures had stronger associations with CTR, some past exposures were also associated with future risk of CTR.