Incidence rates and determinants in meralgia paresthetica in general practice

Objective To determine incidence rates for meralgia paresthetica (MP) in the primary care setting and establish determinants for MP in a case-control study in general practices. Methods Using a cohort (in total 173,375 patient years) of registered persons in primary care from a computerized registration network for general practitioners (GPs) in the Rotterdam area from 1990 to 1998, persons with the diagnosis MP were included. In a nested case-control study we studied the relationship between comorbidity (e. g. carpal tunnel syndrome, pregnancy, osteoarthritis of the hip, overweight, symptoms of the pubic bone, thrombosis of the leg, diabetes mellitus and the use of corticosteroids) and the occurrence of MP. Results The incidence rate of MP is 4.3 per 10,000 person years. MP is more often present in patients suffering from carpal tunnel syndrome OR 7.7 (95 % CI 1.9-31.1) and is related to pregnancy OR 12.0 (95 % CI 1.2-118.0). Conclusions This is the first report on incidence rates of MP and on suspected determinants studied in a case-control setting in general practice. Carpal tunnel syndrome and pregnancy are significantly related to MP. Calculating the Population Attributable Risk in this study leaves 79% of all MP unexplained. Our results suggest that MP is caused by a combined susceptibility for entrapment and a trigger causing entrapment. More research on determinants is needed. Because MP occurs in every GP practice at least once a year more studies are needed on prognosis and treatment.