Degree of urge, perception of bladder fullness and bladder volume--how are they related?

PURPOSE We evaluated the reliability of the degree of urge and perception of bladder fullness scales, the relationship between the scales and bladder volume, and possible differences between bladder sensations experienced in a controlled or an uncontrolled setting. MATERIALS AND METHODS Volunteers and patients with overactive bladder symptoms participated in the protocols. They were asked to grade bladder sensation on a 4-point urge scale of no sensation to need to void now and assess the perception of fullness on a visual analog scale of empty to full bladder. This was assessed in a 3-day bladder diary and during controlled, noninvasive bladder filling. RESULTS Each scale was reliable and significantly related to bladder volume (p <0.001). Agreement between the scales and voided volume was poor. Patients and volunteers grade bladder fullness and degree of urge higher in an uncontrolled than in a controlled setting. CONCLUSIONS The perception of bladder fullness and the degree of urge have a significant relation to bladder volume in controlled and uncontrolled settings. Due to poor agreement between the scales and actual voided volume these scales cannot replace measuring voided volume. The perception of bladder sensation depends on the setting. Bladder sensation at the hospital might underestimate the bother of symptoms experienced by a patient in daily life.