A survey on clinical practice of interstitial cystitis in Japan

BACKGROUND: To explore the real-life practice of clinical management of interstitial cystitis (IC) in Japan. METHODS: A questionnaire on the number of IC patients, cystoscopic findings, diagnostic methods, and the treatment modalities was sent via e-mail to 114 medical institutions belonging to the Society of Interstitial Cystitis of Japan (SICJ). RESULTS: Completed questionnaires were returned from 62 institutions (20 university hospitals, 26 general hospitals and 16 clinics), with a response rate of 54%. The median of patient number per institution was 20 and the national number of IC patients was counted as 4,531 in Japan. The number of new patients in 2013 was 7 (median) per institution and calculated as 1,214 in total. The case volume per institution distributed broadly and skewed to a lower volume. The patients were categorized according to cystoscopic findings as either Hunner type IC with Hunner lesions (n=2,066, 45%), non-Hunner type IC with glomerulations on hydrodistension (n=1,720, 38%) or hypersensitive bladder without endoscopic abnormalities (n=304, 7%), excluding unknown (n=441, 10%). The proportion of Hunner type IC was highly variable among the institutions, ranging from 0% to 100% with a median of 29%. As for evaluation, symptom and quality of life (QOL) assessment by questionnaires, frequency volume chart, urinalysis, urine cytology, urine culture, post-void residual measurement, uroflowmetry, ultrasound and cystoscopy were widely adapted. Administration of oral medicines and intravesical instillation therapy were undertaken at 98% and 63% of institutions, respectively. Hydrodistension was commonly performed, totaling in 812 procedures at 53 institutions, while only five cystectomies were reported from four institutions. CONCLUSIONS: The survey estimated about 4,500 IC patients and 2,000 Hunner type IC patients in Japan. It also revealed a wide range of case volume, acceptable adherence to clinical guidelines, and high variability in the proportion of Hunner type IC. The variable proportions of Hunner type IC despite a high performing rate of endoscopy suggest inconsistency in diagnostic criteria for the Hunner lesion.