The interstitial cystitis data base study: Concepts and preliminary baseline descriptive statistics

Abstract

Objectives To describe the design, patient population, and data and specimen collection aspects of the Interstitial Cystitis Data Base (ICDB) Study and to provide preliminary descriptive statistics and inferential results from an interim analysis. Methods All 424 study participants successfully enrolled in the ICDB Study prior to December 31, 1995, were selected for an interim analysis and were classified into 1 of 3 symptom severity subgroups. Statistical tests for associations among these symptom severity subgroups and a broad range of baseline characteristics were conducted using Mantel-Haenszel procedures to adjust for variation among clinical centers. Results ICDB Study patients are predominantly female (91.5%), white (91.0%), with an average age at enrollment of 44.3 years. Nearly 45% of these patients underwent a cystoscopy at baseline screening, among whom there was an overall prevalence of 10.5% for Hunner's patch and 90% for glomerulations. Urodynamic evaluation for the entire 424 patients demonstrated that volumes at first sensation and at maximal capacity were inversely associated with symptom severity subgroups. A broad range of symptoms were analyzed, indicating that nearly 40% of patients reported urinating 15 times or more during awake hours, and more than 20% reported voiding at least 4 times per night. Almost half (47.9%) reported constant urgency and 23.6% reported having severe pain. Patients in the severe symptom subgroup reported greater limitations in selected quality-of-life indicators than those with less severe symptoms. Conclusions This interim analysis of the ICDB Study data was compared to previous epidemiologic studies of IC and provides an essential foundation for further analytic investigations of baseline associations and longitudinal trends.