Department of Obstetrics and Gynecology;
Asahikawa Medical University;
Asahikawa 078-8510;
Japan;
Department of Urology;
Kanazawa University Graduate School of Medical Science;
Kanazawa 920-8641;
Japan;
Department of Urology;
Dokkyo Medical University Koshigaya Hospital;
Koshigaya 343-8555 Japan;
Division of Public Health and Epidemiology;
Department of Social Medicine;
Asahikawa Medical University;
Asahikawa 078-8510;
Japan;