Patient-Reported Outcomes in Bladder Pain Syndrome: Qui Auget Dolorem, Auget et Scientiam (As Pain Increases, So Increases Knowledge)

Abstract

Bladder pain syndrome/interstitial cystitis (BPS/IC) is a chronic disease characterized by bladder pain and increased urinary frequency and urge to urinate [1]. It still represents a major problem for patients and physicians because its pathogenesis is elusive and treatment remains challenging. To date, the diagnosis of BPS/IC mainly relies on symptoms because we still lack objective evidence of the disease. The need to identify patients with BPS according to symptombased diagnostic criteria is problematic. Physicians have to take into account any confusable disease whose symptoms can overlap those in BPS patients. A great effort has been made recently to create and apply symptom- and problem-based instruments in the diagnosis and treatment of BPS/IC. One of the most important concerns is the identification and evaluation of the appropriate population to treat. The O’Leary-Sant Interstitial Cystitis Symptom Index (ICSI) and Interstitial Cystitis Problem Index (ICPI) were proposed in 1997 as outcome measures in BPS/IC. They both demonstrated an excellent ability to discriminate characteristics between patients and controls [2]. Psychometric properties of ICSI, including variability, test-retest reliability (intraclass correlation coefficient), internal consistency (the Cronbach a), construct validity responsiveness, and clinically meaningful change, were found to be helpful [3]. To date, ICSI and ICPI are recognized among the most reliable and valid instruments to identify the most prominent voiding and pain symptoms in patients with BPS/IC and the extent of the perceived problem, although they do not address dyspareunia or pelvic pain other than bladder pain [4]. Other widely distributed questionnaires for the evaluation of patients with suspected BPS/IC are the Pelvic Pain and Urgency/Frequency Patient Symptom Scale (PUF) and the University of Wisconsin Interstitial Cystitis Scale (UW-IC scale) [5,6]. The PUF questionnaire pays equal attention to pelvic pain, urinary urgency/frequency, and symptoms associated with sexual intercourse. It also correlates well with the results of the intravesical potassium sensitivity test, which is positive in about 80% of individuals with BPS/IC [5]. Similarly, the UW-IC scale shows psychometric properties analogous to other measurement instruments used in clinical research, with a Cronbach a of 0.84 [6].