Incidence rates of surgically treated idiopathic carpal tunnel syndrome in blue- and white-collar workers and housewives in Tuscany, Italy

Objectives: Rates of surgically treated carpal tunnel syndrome (CTS) among blue-and white-collar workers and housewives in the general population were compared. Methods: Surgically treated cases of idiopathic CTS were investigated among 25-59-year-old residents of Tuscany, Italy, during 1997-2000, based on obligatory discharge records from all Italian public/private hospitals, archived according to residence on Tuscany's regional database. Population data were extracted from the 2001 census. Results: After excluding repeat admissions, 8801 eligible cases were identified. Age-standardised rates (per 100 000 person-years) of surgical CTS were: "blue-collar women'', 367.8; "white-collar women'', 88.1; "house-wives'', 334.5; "blue-collar men'', 73.5; and "white-collar men'', 15.3. Compared with reference categories (same-sex white-collar workers): female blue-collar workers experienced a 4.2-fold higher standardised rate; housewives, a 3.8-fold excess; and male blue-collar workers, a 4.8-fold excess (all p < 0.001). Male and female blue-collar workers showed approximately three to sevenfold higher age-specific rates compared to their white-collar counterparts (all p, 0.001). Housewives' rates were similar to those of blue-collar female workers up to 4044 years of age, after which they were significantly lower (p < 0.002). At all ages, housewives' rates were much higher (p < 0.001) than those of white-collar women. Conclusions: Surgically treated CTS was three to seven times more common (depending on age/gender) in blue-collar than in white-collar workers, which is difficult to explain by differences in body weight or other individual factors. Thus, occupational risk factors seem relevant throughout working life. The high rates for full-time housewives suggest that domestic chores should be investigated as a possible risk factor for CTS.