[Carpal tunnel syndrome surgery in France in 2008: patients' characteristics and management].

INTRODUCTION: Carpal tunnel syndrome (CTS) is the most common upper limb neuropathy. There has been a dramatic increase in CTS surgery since the 1990s. This study focuses on changing incidence of CTS surgery in France and associated factors.

PATIENTS AND METHOD: Cases of CTS surgery were identified using the national hospital discharge database for persons living in metropolitan France. Patient characteristics, comorbidities and care management were studied using the reimbursement database of the beneficiaries covered by the general health insurance scheme (76% of the 64-million French population) comparing those with or without CTS surgery in 2008.

RESULTS: In 2008, hospital admissions for CTS surgery were identified in 127,269 patients aged 20 years and older, giving an overall incidence of 2.7/1000 (females 3.6/1000, males 1.7/1000) in metropolitan France. Between 1999 and 2008, the number of patients with CTS surgery increased 25%. Half of this increase was directly related to increasing demographics. For people in the 20 to 59-year age range, incidences were respectively 2.5/1000, 3.6/1000 and 1.3/1000 with high regional variations (1.1/1000-5.5/1000). Individuals aged 60 years and older accounted for 36% of the patients. Using a negative binomial regression, regional incidence variation was significantly and positively associated with the regional density of surgeons practising CTS surgery, proportion of manual workers in the population and proportion of employment in the industrial sector and negatively associated with densities of primary care physicians, rheumatologists and physiotherapists. Certain comorbidities were found to be significantly associated with CTS surgery: diabetes mellitus (Relative Risk [RR]=1.6), hypothyroidism (RR=1.3), end-stage renal disease treated with dialysis (RR=3.3), depression (RR=1.5), hereditary metabolic disease (RR=1.3), ankylosing spondylosis (RR=1.5). Interestingly, a significant negative association was found for full healthcare coverage linked with very low income (RR=0.7) and certain chronic diseases: Alzheimer's disease (RR=0.3), Parkinson's disease (RR=0.7), neuroleptic medications (RR=0.4), multiple sclerosis (RR=0.7). This could be associated with lower frequency of occupational risk factors and a lack of complaint or investigation. After surgery, 55.0% of the patients in the 18 to 59 years age range had a period of sick leave and 36.8% returned to work later than the upper limit of the recommended recovery period of 56 days. The annual cost of sick leaves was estimated at 81 million euros for the general health insurance scheme.

CONCLUSION: The number of CTS surgical procedures is increasing in France. Prevention of CTS in the workplace must be sustained and encouraged. Recommendations for sick leave periods should be followed.