Overactive bladder (OAB), a multifaceted symptom complex, is most common in women and comprised of urinary urgency, frequency, nocturia and urge incontinence [1]. It is defined as a symptom complex due to its unknown etiology [2]. In this novel study, we aim to evaluate the correlation between symptom questionnaires and bladder diaries with respect to urgency void incidents (UVI) in women. This study was completed using a mobile app* in which patients completed the Lower Urinary Tract Symptom Score (LUTSS) questionnaire and a 24-hour bladder diary (24HBD) that documented each micturition accompanied by UVI.

In this IRB approved study, an established database was searched to identify women ≥18 years of age who completed a 24-HBD and/or LUTSS questionnaire from 2015 through 2018. The LUTSS questionnaire is a validated 14 item symptom questionnaire consisting of a total and 6 sub scores – voiding dysfunction, storage symptoms, OAB, incontinence, nocturia and bother [3]. The OAB sub score is comprised of seven questions relating to OAB - urgency, frequency, urge incontinence, and bladder control. The score ranges from 0 - 24, with 24 being maximum symptom severity. 

Data from OAB sub score of the LUTSS and 24HBD were contemporaneously matched within a two-week period. Women with significant changes in symptoms or management during the two-week period and/or had incomplete data entry were excluded.  The 24HBD documents the time and volume of each void and whether it was accompanied by a UVI. The total number of voiding incidents in 24 hours accompanied by UVI was correlated with the OAB sub score using Pearson’s correlation coefficient (r).

262 women completed the LUTSS questionnaire, of whom 145 had a contemporaneous 24HBD. 5 patients were excluded due to incomplete/inaccurate data entry. 140 female patients were included (mean age 54, SD 15) in the study. A scatter-plot of the number of UVI micturition incidents versus the OAB sub score is shown (Figure 1). Three significant observations were found: 1) The correlation between the UVI and OAB sub score is a positive weak correlation, with a coefficient (r) = .13 of p< .01. 2) Some patients recorded up to 14 UVI but only reported mild symptoms with an OAB sub score of < 5. 3) Other patients reported no UVI but more severe symptoms with an OAB sub score of > 10.

The weak correlation between reported symptom scores and bladder diaries shows a lack of alignment between the perception of symptom severity and results from an objective tool, such as a bladder diary. Possible explanations for this include: 1) differences in patients’ perception of symptoms, 2) variations of symptoms that are better illustrated by patients’ recollection over a period of time rather than a time-limited diary, or 3) patients’ difficulties in expressing personal experiences into a symptom score and bladder diary.  

One weakness in this study is that only one 24HBD was utilized rather than the 3 day bladder diary used in most clinical studies. We accepted a lower test-retest reliability in return for a higher compliance rate and because of the well documented lower compliance with longer bladder diaries [3].

This study disclosed an unexpected disparity between the OAB sub scores of the LUTSS questionnaire and 24HBD due to a weak correlation. Based on this, patients’ perceptions of symptom severity do not align with results from a more objective tool such as a bladder diary. 

The 24HBD offers a snapshot of the patient’s symptoms while the LUTSS reflects the patient’s recollections over an extended time period. Clinical conclusions based on either instrument alone appear to be unreliable and should be interpreted with caution. We believe the two instruments are complementary. So, as clinicians - what is the best approach to evaluate patients: a questionnaire, bladder diary or both? 

*WeShareUro by Symptelligence Medical Informatics LLC.

Abrams P, Cardozo L, Fall M, et al. The standardization of terminology in lower urinary tract function: report from the standardization sub-committee of the International Continence Society. Urology 2003; 61:37-49
Blaivas, J. (2003), Overactive bladder: symptom or syndrome?. BJU International, 92: 521-522. doi:10.1046/j.1464-410X.2003.04445.x
Blaivas JG, Tsui JF, Mekel G, et al. Validation of the lower urinary tract symptom score. Can J Urol. 2015;22(5):7952-7958.