CARPAL-TUNNEL-SYNDROME - WHAT IS ATTRIBUTABLE TO WORK - THE MONTREAL STUDY

Objective-To estimate the fraction of carpal tunnel syndrome (CTS) tha t is attributable to work in the total adult population of the island of Montreal. Methods-The population consisted of 1.1 million people 20 to 64 years of age, with 73.2% of men and 60.6% of women employed. Th e rates of first surgery for CTS were compared between occupational gr oups and the total adult population with the standardised incidence ra tio (SIR) method. Rates of surgery for the island of Montreal were obt ained from the provincial data base of payments. The occupational hist ory was obtained from telephone interviews of a sample of surgical cas es. The attributable fractions in exposed people were calculated with odds ratios (ORs) obtained from logistic regressions with non-manual w orkers as the control group. Results-The surgical incidence of CTS was 0.9/1000 adults. SIRs for all manual workers were 1.9 (95% confidence interval (95% CI) 1.4-2.5) in men and 1.8 (95% CI 1.4-2.2) in women, and the fractions attributable to work were 76% (95% CI 47-88) and 55% (95% CI 33-69), respectively. Seven occupational groups were identifi ed as having excess risk of surgical CTS, with fractions attributable to occupation ranging from 75% to 99%. Conclusion-Among manual workers on the island of Montreal, 55% of surgical CTS in women and 76% in me n was attributable to work. Increased risk of surgical CTS was found i n seven occupational groups.