Carpal tunnel syndrome (CTS) in the Piedmont Region: regional incidence and prevalence of CTS based on hospital records of patients who underwent surgery

BACKGROUND: Carpal tunnel syndrome (CTS) is the most frequent entrapment neuropathy of the upper extremities. Despite CTS being a priority for public health, only a few studies have investigated the prevalence and incidence in the general population. In Italy, administrative data are available only for CTS cases which were judged work-related by the Workers Compensation Board. These data indicate a steady increase in CTS over the last decade. Hospital admission archives (SDO) also contain information on CTS patients who underwent surgery. OBJECTIVES: To determine: 1) the incidence and prevalence of first CTS, based on hospital records of patients who underwent surgery in the Piedmont Region; 2) to describe the geographical and temporal variation. METHODS: Crude and standardized incidence rates of CTS were computed for the period 2002-2003; geographical variation was assessed using bayesan estimators to detect spatial clusters. Crude and standardized prevalence rates of first hospitalization were calculated for every two-year period between 1996 and 2003. RESULTS AND CONCLUSIONS: The crude incidence rate was 227.2 (C.I.95% 221.9-232.7) per 100,000 women and 54.4 (C.I. 95% 51.9-57.1) per 100,000 men. The prevalence of first hospitalization was very high and varied widely by geographic area. Two possible explanations for such wide variation between areas include differences in exposure to risk factors for CTS and in the diagnostic criteria used. The increasing prevalence over time was only partly explained by an increase in work-related cases. The development of standardized diagnostic criteria would improve understanding of the effect of workplace exposures on CTS. The number of new cases per year in Piedmont was estimated at 1,500, much higher than the compensation claims related to CTS. Health education campaigns addressed to general practitioners on compensation law could improve reporting to the workers' compensation board.