Voiding diary aids urinary diagnosis
medwireNews: Researchers have found that a 3-day voiding diary can help physicians to distinguish patients with overactive bladder (OAB) from those with bladder pain syndrome/interstitial cystitis (BPS/IC).
They say the method could provide a simple, low-cost means to distinguish the two conditions, something that often presents a clinical challenge.
“Clinicians often have difficulty differentiating BPS/IC from OAB because of similar and overlapping [lower urinary tract symptoms],” explain Seung-June Oh (Seoul National University Hospital, South Korea) and colleagues.
They add: “It is important that these two disorders be differentiated, because they have distinct pathogenesis, and management strategies differ.”
Among 301 OAB patients and 49 BPS/IC patients, completion of a 3-day voiding diary revealed that, while mean total daytime and nighttime voiding volumes were no different between the groups, there were significant differences in voiding frequency, indicating that patients with BPS/IC void smaller volumes at more frequent intervals.
The average voiding frequency in these patients was 13.1 times during the daytime, and 3.2 times during the nighttime. This compared with 6.2 and 2.2 times, respectively, among patients with OAB. Consequently, mean void volumes were smaller in patients with BPS/IC, at 85.4 mL in the daytime and 111.0 mL in the nighttime versus a respective 147.9 mL and 157.9 mL in patients with OAB.
On multivariate analysis, three elements of the voiding diary significantly distinguished between the two conditions: total nighttime frequency, which was higher in BPS/IC patients; nighttime maximal voided volume, which was higher in OAB patients; and the range of daytime voiding intervals, which was greater in OAB patients.
“The different voiding characteristics of the two groups might be explained by their different habit of urination, which results from different pathogeneses of BPS/IC and OAB,” the authors suggest.
They write in the International Journal of Urology: “The BPS/IC patients void frequently with small volume to prevent severe pain produced by bladder expansion, and this results in a relatively constant voiding pattern. However, the OAB patients void with urge to prevent the fear of incontinence rather than pain, so their voiding pattern is different from BPS/IC with a much wider range of volume, frequency and time intervals.”
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By Kirsty Oswald, medwireNews Reporter