MP18-07: Assessment of Bladder &[Prime]Pressure&[Prime] and &[Prime]Discomfort&[Prime] Symptoms – How do Overactive Bladder Differ from Interstitial Cystitis/Bladder Pain Syndrome Patients?

Angelíca Gousse, Joel Vetter, H. Henry Lai*, St Louis, MO

Introduction: The descriptors ?pain, pressure or discomfort? are used collectively to describe the abnormal bladder or pelvic sensations associated with interstitial cystitis/bladder pain syndrome (IC/BPS).   The reference to chronic pain in IC/BPS is universally accepted, however the reasoning for including pressure or discomfort in the descriptors of IC/BPS remain unclear.  Overactive bladder (OAB) patients sometimes described their urgency as pressure or discomfort in qualitative interview studies. This can lead to confusion since pressure or discomfort are embedded in the case definition of IC/BPS. Our objective is to better understand the sensation of bladder pressure and discomfort, and how they are similar or distinct from pain (the cardinal symptom of IC/BPS) and urgency (the cardinal symptom of OAB) in the two clinical populations.

Methods: In this study, we asked IC/BPS (N=27) and OAB (N=51) patients to rate their bladder pain, pressure, discomfort, and urinary urgency sensation separately on numeric rating scales.  We then compared their ratings of 0-10 (0 = no symptom, 10 = high symptom) of pain, pressure, discomfort and urgency and their correlations, to discover group differences between IC/BPS and OAB patients.

Results: Among IC/BPS patients, their mean numeric ratings of pain, pressure, or discomfort were almost identical (6.2 ± 2.3, 6.0 ± 2.1 and 6.6 ± 2.5 respectively).  In addition, the three-way correlations between pain, pressure, or discomfort were very strong (all >0.77).  The correlation between pain and discomfort ratings was extremely high at 0.95, suggesting that IC/BPS patients interpreted pain and discomfort as similar concepts and rated their intensity nearly identical.  Among OAB patients, the correlations between pain and urgency (0.21) and between pressure and urgency (0.26) were very weak.  The correlation between discomfort and urgency was moderate (0.45).  OAB patients could distinguish urinary urgency from pain and pressure, but urgency and discomfort symptoms were less clear.

Conclusions: IC/BPS patients interpreted bladder pain, pressure, or discomfort as the similar concepts and rated their intensity similarly. The concurrent use of three descriptors pain, pressure, or discomfort is reductant among IC/BPS.  Bladder pain separated OAB from IC/BPS better than pressure or discomfort. OAB patients can distinguish urinary urgency from pain and pressure, but this is less clear cut between urgency and discomfort.

Source of Funding: NIH/NIDDK