Validation of a water-load protocol to define the pattern of bladder sensation.

INTRODUCTION AND HYPOTHESIS: The aim of this study was to confirm reliability of a water-load diuresis protocol and to assess the utility of bladder sensation curves. METHODS: For confirmation of fixed diuresis rate (phase 1), 12 volunteers consumed 250-300 ml of water every 15 min and recorded bladder sensation on a visual analogue scale (VAS) every 5 min to maximum sensation over two filling cycles: voids 1 and 2 (V1 and V2). The test was performed twice. For test-retest validation (phase 2), 24 participants underwent the same protocol drinking 300 ml of water every 15 min. Diuresis rates and voided volumes were compared between cycles and across tests. RESULTS: In phase 1, there was no difference in median void volume (V1 735 ml, V2 678 ml p = 0.433) or median diuresis rates (V2 12.1 ml/min, V3 14.4 ml/min p = 0.136) between cycles. When comparing those who drank 250-300 ml/15 min, there was less variability in those drinking 300-ml aliquots, so this was standardised for later experiments; 95% upper confidence limit of variability of the diuresis rate was calculated as 4.5 ml/min. Any test with a greater difference was rejected as invalid. In phase 2, only 16 participants were analysed. There was no difference in median void volumes between tests [V1 763 ml and 820 ml (p = 0.109) and V2 788 ml and 796 ml (p = 0.266)] or in diuresis rates between test 1 (12.33 ml/min) and 2 (14.40 ml/min) (p = 0.056). Median area under the curve was similar between test 1 404.96 and test 2 418.63. CONCLUSIONS: This refined protocol reliably produced stable diuresis with a water load of 300 ml/15 min, excluding those with a difference in diuresis rate > 4.5 ml/min.

Evaluation of the IncoStress device for urinary incontinence: a feasibility study and pilot randomised controlled trial.

INTRODUCTION AND HYPOTHESIS: The aim of this study was to assess the feasibility of recruitment to and outcomes from a pilot randomised study of the IncoStress device as an adjunct to conservative treatment for urinary incontinence. METHODS: Women with urinary incontinence were randomised on a 2:1 basis to usual care (control) or usual care plus use of the IncoStress device (intervention). Process outcomes (retention and compliance) were recorded plus symptom outcomes (IQOL and ICIQ-FLUTS questionnaires). A sample of participants took part in an interview to understand the frequency of use of the device and satisfaction. RESULTS: Eighty women (51 intervention, 29 control) were recruited. Follow-up responses were obtained from 34 intervention group (66.7%) and 17 (58.6%) control patients. Women used the device for a median 3 days a week (0-7), 18 out of 34 (53%) found it easy to use and 21 (61.8%) were satisfied with the device. Median IQOL score in the intervention group improved from a baseline of 42.4 (0-94) to 68.2 (5-98) at follow-up and in the control group from 45.5 (0-88) to 53.0 (0-94). Median ICIQ-FLUTS score in the intervention group improved from 14.5 (6-35) to 12.5 (4-26) and in the control group from 15.0 (5-35) to 14.0 (6-38). CONCLUSIONS: Recruitment and randomisation were feasible and robust. This study demonstrates that a large-scale RCT is feasible and the IncoStress has potential value.

Methods of assessing and recording bladder sensation: a review of the literature.

INTRODUCTION AND HYPOTHESIS: The objective was to review different methods that have been used to assess bladder sensation and to provide an overview of the accuracy and objectivity of the measurement of the subjective perception of the bladder. METHODS: The MEDLINE and PubMed databases were searched to identify articles. References from those articles were also searched. Terms used for the search were: urinary bladder, sensation, cystometry, urodynamics, urinary incontinence and focus group. Eight hundred and fifty abstracts were identified from databases, and 12 from other sources. Twenty-two duplicate articles were removed. Irrelevant articles were excluded after reading their titles. Fifty-four articles were eligible, but 17 were excluded after reading the full text, leaving 37 articles where assessment of bladder sensation was the main aim. RESULTS: Six different methods of measuring bladder sensation have been described in the literature. Although the most frequently used was cystometry, this is an invasive tool and does not reproduce bladder behaviour during daily life because it records bladder sensation as episodic events. The visual analogue scale using a forced diuresis protocol seemed to be an excellent tool. It was non-invasive and evaluated bladder sensation continuously, from an empty to a full bladder. CONCLUSIONS: In some of the studies, the samples were too small to draw any significant conclusions. There were also conflicting data on which tool was the most accurate, especially as each method of evaluating bladder sensation may influence the way it is described by participants.