To describe the distribution of and factors associated with healthy bladder storage and emptying functions in community-dwelling women using a novel 2-day bladder health diary.

We conducted a secondary analysis of participants enrolled in a U.S. cross-sectional study designed to validate a novel bladder health instrument (BHI).(1)  Women aged 18+ years were recruited between September 2019 and August 2020 using a delivery sequence file address-based probability sampling frame. Those who completed the primary surveys, which included demographic and medical history, were invited to complete a 2-day bladder health diary.  The diary captured bladder storage symptoms (frequency, continence, sensation of urgency and pain), emptying symptoms (initiation, flow, efficacy, relief of urge sensation and pain), and were used to define each individual storage and emptying function (e.g. post void dribbling PVD was captured in column 6, Figure 1.) “Overall healthy bladder function” was defined as up to a mean of 8 voids during waking hours, 0 voids during sleeping hours, and the absence (on both days) of urinary leakage, urinary urgency, or voiding difficulties (including post void dribbling; [PVD]). (2) “Overall healthy voiding experience” was defined as yes responses to “easy starting to pee, continuous stream, feeling the bladder empty and the need to pee feeling is gone;” plus a no response to the item “did you dribble pee when you were done?”  Descriptive statistics were used to report overall prevalence of healthy bladder functions.  Prevalence of healthy function for each storage and emptying function was assessed.  Descriptive statistics were also used to report urinary frequency (waking and sleeping) as well as to describe the prevalence of unhealthy functions including presence and amount of urinary incontinence, frequency of urgency episodes and negative voiding experiences with each void.  Presence of pain with storage or emptying and pad usage on either day was also assessed. Means, standard deviations (SD), medians, interquartile ranges (IQR) were used to describe the distribution of voiding frequencies.  Stepwise logistic regression models included characteristics associated with healthy function at a p<0.2 on univariate analysis to identify factors associated with healthy bladder function and reported in Odds Ratios (OR) with 95% Confidence Intervals (95%CI). Missing values were handled by single imputation using fully conditional specification methods.

Of 605 respondents in the primary study, 248 returned the 2-day bladder health diary.  The mean age was 56.2±15.4 years with 36% being normal weight, 2% underweight and 52% overweight/obese; 53% denied comorbid conditions; 4% were Asian, 6% Black, 88% were non-Hispanic white. Only 12% of women (30/244, 4 missing) had overall healthy bladder function based on our strict definition. Healthy storage function, with voiding frequency during waking hours of 8 or fewer times per day, occurred in 74% (183/248), and 51% (127/248) reported 0 episodes of nocturia. Nocturia occurred once in 30% (74/248), twice in 13% (31/248) and 3 or more times in 6% (16/248). Frequency of urination was 7.6±2.3 (median=7, IQR=3) per 24 hours (7.2±2.2; median=7, IQR=3 during waking hours and 0.8±1.2; median 0, IQR=1 during sleeping hours).  A total of 63% (157/248) denied any urine leakage on their 2-day diary; however, those with leakage reported 1.9±1.8 (median=1, IQR=2) leaks per 24 hour period with the majority of leaks being of small volume (68%), and the rest medium (20%) or large (12%) volume.  Only 29% (72/248) denied any urgency episodes over 2-days. In those with urgency, the mean daily number of urgency episodes was 3.3±2.5 (median=2.5, IQR=4) and within those women who reported any urgency 39% (IQR=45) of their daily voids were associated with urgency.  Overall healthy voiding experience was noted in 47% (91/248) of women. Of those with unhealthy voiding experiences the most common was PVD at 84% (132/157) followed by non-continuous stream (50%, n=80/157), feeling of incomplete emptying (32%, 51/157) and persistent “need to pee” (26%, 40/157). Of those reporting one or more unhealthy voiding experiences on either day of the diary, the median percentage of voids described as unhealthy was 39% (IQR=49). The majority (92%, 225/244, 4 missing) of women denied pain during storage or voiding and of those with pain, 58% (11/19) reported pain with holding, 47% (9/19) pain with peeing and 5% (1/19) pain with both.

Stepwise logistic regression models (Figure 2) identified higher income (OR:95%CI=26.3: 2.8-249.5 for >$150,000 vs. <%50,000), and never previously seeking treatment for bladder problems (OR:95%CI=0.1; 0 -0.9) as associated with overall healthy bladder function. Those with healthy voiding frequency, absence of leakage or PVD were less likely to have sought treatment for bladder problems (OR:95%CI = 0.3: 0.2-0.7;  0.3: 0.1-0.5; 0.2: 0.1-0.5 respectively).  Those without leakage, urgency and PVD had fewer comorbidities (OR:95%CI= 0.7: 0.5-0.9; 0.6: 0.4-0.8; and 0.2: 0.1-0.5 respectively.  Those working, compared to not working, were more likely to not wake up from sleep to urinate (OR:95%CI: 2.8; 1.3-5.8).  There were too few women with pain to evaluate associations between pain free bladder experiences and baseline characteristics.

The prevalence of overall healthy bladder function for all storage and emptying components, as measured using a 2-day bladder health diary, was very low. Although three in four women void fewer than 8 times during waking and 0 to 1 times during sleeping hours, most community-dwelling women report voiding irregularities and urinary urgency occurring approximately 3 times per day. Two thirds of women deny leakage; however, in those who do report leakage, most have small amounts approximately 2 times a day.  Factors associated with healthy bladder functioning include fewer comorbidities, financial security and being a student or working at a job.  As expected, having not sought care for bladder problems was associated with healthy storage and emptying functions.

A strict definition of overall bladder health based on bladder diaries alone may not represent “normal.”  The presence of a sudden and urgent need to pee may not be unhealthy, rather a natural response when storage capacity is stressed. Voiding difficulties including PVD and non-continuous stream also occur commonly.  Further investigation into whether these clinically defined perturbations in bladder storage and emptying functions are also perceived as unhealthy by women is critical to developing a more informed definition of bladder health and shared treatment goals.

BMC Womens Health. 2021 Dec 1;21(1)
Neurourol Urodyn. 2019 Apr 8; nau.23985

Continence 2S2 (2022) 100274
DOI: 10.1016/j.cont.2022.100274