Nationwide Estimation for Incidence at Birth of Congenital Polydactyly and Syndactyly in Korean

ABSTRACT

INTRODUCTION: The aim was to estimate the incidence at birth of congenital polydactyly and syndactyly to use medical utilization database of the National Health Insurance Corporation in Korea. MATERIAL & METHOD: Base population are selected from the children born in 1994(n=728,515). The diseases were identified by disease code system; ICD-9 755(Other congenital limb-anomalies), ICD-10 Q69(Polydactyly), ICD-10 Q70(Syndactyly), ICD-10 Q66(Other congenital feet-deformities), ICD-10 Q74(Other upper limb-anomalies). The suspicious cases of polydactyly and syndactyly are selected from the base population with those criteria(n=3,497). The 669 cases, 16 university hospitals and 16 hospitals have been examined the name and location of anomaly through medical record review. The diagnostic accuracy by Disease-code system was calculated. The incidence rate at birth was estimated by the class of polydactyly/syndactyly, adjusted for the diagnostic accuracy. RESULT: The incidence per 100,000 birth are estimated; at hand, polydactyly, 93(95% confidence interval 86-100), syndactyly, 29(25-33), polysyndactyly, 13(11- 16); at foot, polydactyly, 40(36-45), syndactyly, 22(19-26), polysyndactyly, 14(12 - 17); at multifocal area(hand & foot), polydactyly, 1(0.6 -2), syndactyly, 2(0.9-3), polysyndactyly, 3(2 - 4). CONCLUSION: These incidence rates may be underestimated and show the minimum incidence rates. The incidences must be discussed in comparison with incidences through registry or prospective follow-up study of congenital anomalies.