Incidence and clinical features of priapism in Japan: 46 cases from the Japanese diagnosis procedure combination database 2006-2008.

We investigated the incidence and clinical features of priapism in Japan, using a national administrative claims database, the Diagnosis Procedure Combination database. Priapism patients were identified using the International Classification of Diseases and Related Health Problems, 10th Revision code, N483 (priapism). Verified patient characteristics included age, comorbidities and management of priapism. Among 6.93 million inpatients, 46 patients with priapism were identified. Four had two admissions each for repeated events. The median age was 41.5 years (range, 11-89 years). A total of 21 patients had comorbidities; 3 had haematological malignancies, 4 had haemodialysis, 1 had a renal transplant, 2 had neurological problems, 4 had non-haematological malignancies, 3 had trauma and 6 had psychoses (2 cases had two comorbidities). All patients with non-haematological malignancies were over the age of 70 years, indicating that close attention is required to search for associated malignancies in elderly patients. The medical treatments included 6 vascular embolizations, 11 Winter method surgeries and 18 other operations. The incidence was estimated to be 0.13 (95% confidence interval, 0.097-0.17) per 100,000 person-years. This incidence was lower than that reported in other parts of the world.