A Survey on the Effect of Anticholinergic Therapy on Post-Void Dribbling

ABSTRACT

Purpose: Post-void dribbling (PVD) is a type of incontinence defined as the involuntary loss of urine immediately after passing urine and rising from the toilet. The purpose of this study was to evaluate whether anticholinergic therapy reduces symptoms of PVD in women placed on therapy for overactive bladder (OAB).

Methods: A survey was administered via telephone to patients being treated for OAB with anticholinergic medications who also carried a diagnosis of PVD. Patients were asked whether PVD symptoms had worsened, were unchanged, or had improved on anticholinergic therapy. Variables such as drug response to OAB symptoms, non-drug treatments for incontinence, and compensatory behaviors to avoid PVD symptoms were included. Other symptoms and variables of voiding dysfunction and medical comorbidities were collected from the medical record. Standard descriptive statistics, Wilcoxon rank sum, and Fisher’s exact tests were used to describe the data.

Results: Sixty participants completed the survey. Of the eligible patients, 82% consented to participate in the survey. Of those, 72% (95% CI: 59%-83%, p < 0.01) improved PVD symptoms on anticholinergic therapy. The response rate for OAB was also 72%. No difference was found between the response to PVD and OAB (p = 1). No other variable measured affected improvement in PVD symptoms on anticholinergic therapy.

Conclusions: In our survey, anticholinergic medications appeared to be effective in treating PVD with an efficacy similar to that of OAB. Additional studies are needed to confirm these findings.

Jessica Rasmussen, Songwon Seo, Tova Ablove

Submitted February 10, 2012 - Accepted for Publication April 17, 2012

KEYWORDS: Incontinence, overactive bladder, post-micturition dribble, survey, urge incontinence, women

CORRESPONDENCE: Tova Ablove, MD, MSc, Assistant Professor, Department of Obstetrics and Gynecology, University of Wisconsin at Madison, Wisconsin, United States ().

CITATION: UroToday Int J. 2012 June;5(3):art 14. http://dx.doi.org/10.3834/uij.1944-5784.2012.06.01

INTRODUCTION

Post-void dribbling (PVD) is a type of incontinence defined as the involuntary loss of urine immediately after passing urine and rising from the toilet [1]. Urinary incontinence is a common condition affecting 1 in 20 American women [2], many of whom complain of PVD as part of their symptoms. A prior study evaluating urinary incontinence found the prevalence of PVD among incontinent women in the general population to be 16.2% [3]. Coyne et al. reported on the prevalence of lower urinary tract symptoms (LUTS); they evaluated a cross-section of the population and found that 15.9% of women over 40 years had reported PVD sometimes, and 9.4% reported PVD symptoms often [4]. In our prior study [5], we noted PVD in 44% of women with overactive bladder (OAB). We also found OAB more common in women with symptoms of PVD; 85% of women with PVD had symptoms of OAB. The primary aim of this study was to evaluate the effect of anticholinergic therapy on PVD symptoms in patients being treated for OAB. We hypothesized that patients with PVD on anticholinergic therapy would have improvement of their PVD symptoms.

MATERIALS AND METHODS

IRB approval was obtained prior to the initiation of the study. We administered a survey to a cohort of female patients being treated for OAB with anticholinergic medications who also carried a diagnosis of PVD.

Potential subjects were identified using a medical record query, and were prescreened. This cohort was mailed an introductory letter and contacted approximately 1 week later. The study was described and subjects were then screened for eligibility. Eligible subjects were invited to participate in the survey.

Inclusion criteria included: female patients between 18 and 89 years of age with PVD symptoms at least twice per week; patients were on anticholinergic therapy or had been on anticholinergic therapy within the past 30 days. Exclusion criteria included: pregnancy, conditions which would prevent participation in a survey, including non-English speech, dementia, and mental illness.

An electronic medical record database query was run at the University of Wisconsin School of Medicine and Public Health in March of 2009. We searched for the diagnosis of PVD and the presence of anticholinergic drugs on an active medication list within a single urogynecology clinic. Anticholinergic medications for the treatment of OAB included solifenacin, darifenacin, oxybutynin, tolterodine, and trospium. Information was extracted from the medical record to prescreen for eligibility; the diagnosis of PVD and the use of anticholinergic medications within the past 30 days were confirmed. To receive the diagnosis of PVD in the medical record, the patient had to complain of symptoms of urine leakage after voiding and rising from the toilet, both on their written urinary history questionnaire and at their initial interview visit. Patients were asked “After urinating, do you have dribbling of urine when you stand up?” in a urinary history questionnaire mailed to the patient prior to the new patient visit. At the new patient visit, the patients were asked “Do you ever leak urine after urinating and have risen from the toilet?” If the answer was yes on both questions, and it occurred more than 2 times per week, a diagnosis of PVD was entered into the medical record. Patients were excluded if they were 90 years or older, 17 years or younger, pregnant, non-English speaking, or not competent to answer questions due to mental Illness/dementia.

An information sheet describing the study was sent to prescreened patients approximately 1 week prior to contact. Two members of the research team contacted the patients by telephone. Potential subjects were asked to confirm the presence of PVD. If they denied having symptoms of PVD prior to treatment they were not included in the study. They were also specifically asked if they had been on anticholinergic medications in the past 30 days. If they had not been on medications for the past 30 days they were excluded from the study. After screening, eligible patients verbally consented and were asked several scripted questions.

The survey’s script asked for the name of the medication being taken. Subjects were asked if the medication helped with OAB symptoms. They were also asked if they have had any additional treatments for incontinence, such as Kegel exercises, InterStim therapy, sling procedures, and estrogen therapy. Further, they were asked if their PVD symptoms had resolved, had improved, or if they remained unchanged since starting therapy. Finally, subjects were asked if they do anything to avoid episodes of PVD, such as waiting on the toilet after voiding for a “second void,” or changing position during or after voiding to elicit additional urine.

Medical records were reviewed in this cohort of patients to gain additional demographic information, including body mass index, diabetes, recurrent urinary tract infection (UTI), multiple sclerosis, urethral diverticulum, prior prolapse surgery, prior incontinence surgery, pelvic organ prolapse, nocturnal enuresis, pelvic pain, dysuria, dyspareunia, stress incontinence, OAB and urodynamic testing information, maximum urethral closure pressure, and post-void residual.

The data were compiled and summarized by standard descriptive statistics, which included means, standard deviations, ranges for variables on a continuous scale, and frequency tables for variables on a categorical scale. For the comparison of patients’ characteristics between responders and non-responders, Wilcoxon rank sum test and Fisher’s exact test were used for continuous variables and categorical variables, respectively. In addition, a McNemar’s test was used to examine 2 paired response rates for PVD and OAB. The number of patients initially planned was 68 in order to test the null hypothesis that the true response rate was 35% versus the alternative hypothesis that it was at least 50%, with 80% power and a 5% significance level. We used a lower response rate than that seen for OAB, based on the assumption that this treatment would be less effective for PVD. We chose these parameters based on the published response rates to anticholinergic medications [6].

RESULTS

We contacted 73 eligible subjects to participate in the study. Thirteen declined to participate. The total number of subjects available to participate in this study was 60. Anticholinergic medications were effective in treating PVD, with a response rate of 72% (95% CI: 59 to 83%, p < 0.01). When patients who declined to participate in the study were included in the “non-responder” group during data analysis, the response rate fell to 59% (95% CI: 47 to 70%); however, the response rate was still greater than 35% (our null hypothesis), with statistical significance. We noted an almost complete concordance in response to medication; if patients responded to their anticholinergic medication for OAB they also responded for PVD. The converse was true; if they did not respond to anticholinergic medications for OAB they did not respond for PVD either. Statistical significance was not found in the difference between the responses to PVD and OAB (p = 1).

We reviewed the medical history of the study subjects and found no difference in symptoms or medical conditions between those who responded and those who did not respond to anticholinergic medications. See Table 1, Table 2, and Table 3.

DISCUSSION

In our survey, anticholinergic medications were effective in treating PVD. The response rates mirrored those of anticholinergic medications for OAB symptoms in the literature, typically ranging from 60 to 70%. Response rates to a placebo in urge incontinence studies are approximately 35% [6].

PVD is an important type of incontinence; it is relatively common and negatively affects quality of life. Temml et al. [3] found the prevalence of PVD in 16.2% of incontinent women (at least 1 episode in 4 weeks). They also noted PVD significantly decreased quality-of-life scores; 14.4% of incontinent women had a moderate to severe decrease in quality of life due to PVD. These findings underline the importance of PVD as a type of female lower urinary tract dysfunction. Coyle et al. [4] reported similar findings for prevalence and quality of life.

PVD can occur in women without OAB symptoms. In our prior study [5], we examined women evaluated for lower urinary tract symptoms (n = 161). Of patients examined, 41% had PVD (n = 68) and 15% of the patients with PVD did not have urge incontinence (n = 10). This 15% would go untreated without knowledge of the relationship between PVD and anticholinergic meds. Women with OAB, in theory, may have their PVD incidentally treated when they are being treated for OAB. This is the first report of the therapeutic effect of anticholinergic medications on PVD symptoms.

OAB and PVD are considered distinct clinical entities, each with its own formally recognized definition. Interestingly, there is no overlap of symptoms in their definitions, which would imply a common condition. PVD in women was defined in 2002 by the International Continence Society as “involuntary loss of urine immediately after passing urine and rising from the toilet.” OAB is defined as “urgency with or without urge incontinence, usually with frequency and nocturia” [1].

We noted an almost complete concordance in response to medication; if patients responded to anticholinergic meds for OAB they likely responded for PVD. The converse was true; if they did not respond to anticholinergic medications for OAB they did not respond for PVD either.

The mechanism for how anticholinergic medications improve PVD symptoms in women is unknown, as is the relationship between OAB and PVD. Research in this area is ongoing [7-11]. It is likely that PVD is caused by some type of abnormality in the micturition reflex, which is corrected on anticholinergic therapy.

One of the weaknesses of this study is that all patients received treatment for their PVD symptoms, thus no control group was used. We also used a survey for data accrual, which exposes the data to recall bias. In an attempt to minimize this bias we only included women who were actively on medication or had discontinued medications within the last 30 days [12]. We also used scripted telephone interviews to collect our data so that all patients received the same information in the same way. Another weakness of this study is that all patients had OAB symptoms; therefore, we do not know how women without OAB would respond to therapy.

A review of the literature reveals that only 42% of potential candidates participate in surveys using a single mode. In this study, we used 2 modes of contact: an introductory letter, followed by a phone call. It is likely that this combination of contact methods resulted in 82% of our eligible patients consenting to participate in the survey. Only 13 subjects (18%) contacted declined to participate. This is well above the national standards for survey response rates. There were an additional 7 subjects identified via the medical records query who appeared eligible in the prescreening that we were unable to contact. It is not known whether they would have been eligible to participate in the study after screening was complete.

This study did not discriminate between anticholinergic medications. We assumed that all of the anticholinergic medications would be equally effective in treating PVD since they all have similar efficacy for treating OAB. Although all of the drugs used in this study are of the same class and have the same mechanism of action, their chemical structures do differ somewhat. The structural differences don’t affect the mechanism of action but can alter their pharmacokinetic and side-effect profiles [13,14]. This study design allowed us to have a larger sample size and therefore increased the power of the study. It also improved the generalized and relevant findings. Finally, this study design enabled us to quickly and inexpensively take a “first look” at patient response to anticholinergic medications for PVD. Future studies involving randomized controlled trials are needed to confirm the findings of this initial study.

CONCLUSION

The results of this initial study showed that in our cohort, anticholinergic medications were effective in treating PVD with an efficacy similar to that of OAB. Further research evaluating the effects of anticholinergic medications on PVD symptoms and quality of life are needed.