You are here
Nocturia treatment outcomes: analysis of contributory frequency volume chart parameters
Epstein M, Blaivas J, Wein AJ, Weiss JP
Neurourology and Urodynamics 2017 Mar 31. doi: 10.1002/nau.23272. [Epub ahead of print]
Commentary by Don Bliwise
This short paper describes the extension of the well-known 24-hour frequency volume chart (FVC) to a urologic practice in what might be termed an effectiveness (c.f., efficacy) study for examining treatment outcomes for nocturia. In research performed by the Brooklyn (New York) VA Hospital, pre- and post-treatment FVCs for multiple 24-hour periods were evaluated in 105 men presenting with nocturia. A unique feature of these data is that they were not collected as part of an industry-sponsored clinical trial, but rather were acquired as part of routine clinical care in a large academic group practice. Additionally, treatments for nocturia were not limited to any particular pharmacologic agent and included behavioral interventions, surgical treatments, as well as medications, including anticholinergics, beta 3 agonists, alpha blockers and 5-alpha reductase inhibitors. The sole criterion for improvement was simple and direct: a reduction of 1 (or more) voids per night. Some of the interesting results from this study were that oxybutynin was associated with improvement in 12 cases and lack of improvement in 18 cases, and the improvement among those 12 cases appeared to be related to increased bladder capacity. (Maximal Voided Volume [MVV] was statistically significantly larger in the improved group). By contrast, with alpha agonists (tamsulosin, prazosin), 13 patients with improvement in nocturia showed no differences in MVV when compared to 22 patients whose nocturia did not improve with such medication. Overall, more cases showing improvement in nocturia suffered from nocturnal polyuria (or nocturnal polyuria together with reduced bladder capacity) rather than from reduced bladder capacity alone. Perhaps the most interesting aspect of the results from my perspective as a sleep researcher is that the FVC used by these investigators also provided data on a critical sleep metric, the time to first void, sometimes called the First Uninterrupted Sleep Period (FUSP). FUSP has been shown to be an excellent proxy for sleep quality (and to some extent even sleep length) over the entire night, and although the FVC does not collect detailed data on sleep quality, its derivation of FUSP is an important adjunctive piece of information about disturbed sleep in this population. In this study, patients whose nocturia improved showed a net increase in FUSP of about 2.2 hours over those patients whose nocturia did not improve, thus further validating the robustness of this metric.
Our aim is to determine which changes in frequency volume chart (FVC) parameters are associated with nocturia improvement.
This is a real life retrospective analysis of FVC's of men who were treated for nocturia and completed at least two 24 h FVC's. Patients were divided into two groups-an improved cohort defined by a decrease of ≥1 nocturnal void from baseline and a non-improved cohort.
A total of 414 FVC's were analyzed (207 baseline and 207 post treatment) among a cohort of 105 men. Baseline nocturia severity (ANV, 3.5 vs. 2.3, respectively) and nocturnal urine volume (NUV, 880 mL vs. 650 mL) was greater in the improved cohort compared to the non-improved cohort. The improved cohort had a decreased 24 h volume (-310 vs. +120 mL), and NUV (-290 vs. +170 mL) compared to the non-improved cohort. At the followup visit, the improved cohort experienced a statistically significant decline in ANV (-1.8 vs. +1.0). No significant difference was seen in baseline 24 h volume or bladder capacity (MVV), though patients in the improved cohort experienced a small decrease in MVV. First uninterrupted sleep period (FUSP) increased significantly in the improved cohort (+1.8 h), and dropped (-0.6 h) in the non-improved cohort.
Improvement in nocturia was associated with a decrease in both 24 h voided volume and NUV, but not MVV, suggesting that improved patients consumed less fluid. The increase in FUSP in the improved cohort demonstrates the potential for nocturia therapies to improve impaired sleep architecture.