Urodynamic investigations are a widely accepted tool for measuring functional lower urinary tract abnormalities.1 Cystometry involves the measurement of intravesical pressure during the course of bladder filling and emptying. It is crucial that urodynamic test results reproduce the patient's presenting symptoms, and conventional cystometry has been widely used to identify specific bladder functions. However, the non-physiologic nature of conventional urodynamics (including bladder filling by rapid infusion through a catheter and monitoring in a laboratory setting) fails to provide a diagnosis in a significant proportion of patients.

Ambulatory urodynamic monitoring (AUM) has been presented as a more sensitive and reliable method of detecting and quantifying uninhibited detrusor contractions than standard cystometrograms in various patient groups2-5 based on conventional cystometric criteria. In contrast to conventional urodynamic studies, AUM allows the patient to be more independent than is possible with a fixed urodynamic apparatus. Therefore, this method allows the patient to perform those activities that he or she knows will reproduce the troublesome urinary symptoms.6 Moreover, bladder filling occurs in a natural way and is not artificially influenced. The test is thus considered to be more accurate than conventional cystometry because the physiologic processes are uninhibited.

Although most of the morbidities associated with urodynamic procedures involve minor complications, patients perceive the procedure as traumatic and worrisome. Some patients regard a urodynamic study as an unpleasant and painful procedure. Even when the urodynamic study is performed properly, patients may still have a negative perception of the experience.

Although several studies have mentioned conventional urodynamic7,8 and AUM9-related morbidity, no study has addressed patients' pre-procedure perceptions or post-procedural experiences. The present prospective study was designed to compare patient experiences with conventional urodynamic studies and AUM to verify the hypothesis that AUM is as well tolerated as conventional urodynamic studies.

Between November 2002 and August 2003, consecutive patients who had been referred for urodynamic assessments (including urinary urgency with or without incontinence) were recruited to our study. Approval for this study was obtained from the Internal Review Board of Seoul National University Hospital. Patients referred for this study who provided informed consent were eligible to participate. To be eligible, patients had to be at least 20 years of age or older, be able to complete a questionnaire, and have no previous experience with conventional urodynamic or ambulatory urodynamic monitoring. The exclusion criteria included ongoing infections, an indwelling catheter, an inability to cooperate, and an increased infection risk (e.g., previous heart valve reconstruction, a hip prosthesis, etc.). A total of 33 women and 7 men from 23 to 72 years of age (mean age plus or minus standard error, 47.4 ± 1.9) who were undergoing conventional videourodynamics and AUM were included in the study on a prospective basis. Table 1 itemizes the patient demographics.

All procedures were performed on an outpatient basis. Each patient received a leaflet containing detailed information about the procedure a few days before the procedure took place. A midstream urine specimen was sent for microscopy and sensitivity testing immediately before the investigation. Patients were assessed for pre-procedure anxiety prior to the studies. Conventional urodynamic studies (UD-2000, Medical Measurement System, Enschede, the Netherlands) were performed by one examiner in an identical manner for all patients. Each patient then underwent a free uroflow study and a video-urodynamic study (Ultravist, Schering AG, Berlin, Germany) with contrast-mixed normal saline at a filling rate of 50 mL/min using a dual-lumen single-use 6-French catheter (Medtronic Inc., Skovlunde, Denmark). Standard aseptic methods of catheterization were used. Immediately after the procedure, each patient completed a self-administered questionnaire.

After completing conventional urodynamics, patients then underwent AUM as described by the King's College Hospital Protocol.10 Briefly, the test lasted at least four hours. All transducers were zeroed to atmospheric pressure. An 8-French catheter (Unisensor, Attikon, Switzerland) was inserted urethrally with two pressure transducers in the bladder in order to detect artifacts. Another catheter-mounted microtransducer (Unisensor, Attikon, Switzerland) covered with a condom was inserted into the rectum. Pressures were recorded on a solid-state system (UPS-2020, Medical Measurement System, Enschede, the Netherlands). Urinary leakage was detected using a conductance device. The participants voided on a flowmeter which was connected to a recorder. They were instructed to drink 180 ml of water every 30 min, and to complete a symptom and activity diary during the test. These instructions were carefully explained before the test started. Each participant was asked to note when an event such as urgency or urge incontinence occurred and to record the time using the clock on the display screen of the ambulatory recorder. At the end of each test, patients were asked to wash their hands to provoke urinary symptoms. Immediately after AUM, each patient completed the self-administered questionnaire as described above. The examiner also recorded the degree of patient pain and patient tolerability.

The questionnaire was developed by an investigator (S.J.O.) and has been previously described.11 It was developed primarily by experts and addressed items of interest, including pain, shame, bother, boredom, and intolerance. The content of the questionnaire was thoroughly reviewed and modified by three experts (J.H.K., Yeonsoon Ko, R.N. and Seung Hwa Lim, R.N.). Pilot testing and subsequent person-to-person interviews were conducted on five patients who had undergone a urodynamic study to ensure that the items on the questionnaire were relevant. Some of the questionnaire items were modified due to the feedback obtained. The print layout and arrangement of the questionnaire were designed to allow it to be easily read and answered by patients. The questionnaire was then administered repeatedly at one-week intervals to the 10 patients who were followed-up at the Incontinence Clinic. Preliminary studies revealed that the questionnaire was valid and reliable. Answers were given on a visual analogue scale (VAS).12 The distance from the left end of the scale was used to quantify the variable. The left end of the scale was defined as "not at all" and the right end as "extremely." Patients were also asked to indicate whether they were willing to repeat the examination. The response choices to this question were rated according to a six-point scale: i.e., "not at all," "nearly not," "rather not," "some," "considerably," and "very much" (Appendix 1). After the procedure, the examiner also noted the degree of patient pain and patient tolerability. Answers were given on a VAS as described above. The examiner rated the patient's cooperation from "excellent" at the left end of the scale to "extremely poor" on the right end of the scale (Appendix 2).

VAS measures were analyzed using group means as continuous variables. The Mann-Whitney U test was used to assess the differences between these continuous variables. Correlations of the degree of pain reported by the patient and the examiner were performed using the Spearman correlation test. The influences of a patient's emotional state and the patient's intolerance were explored using a multiple linear regression analysis. A stepwise method was used to select the explanatory variables based on the analysis of variance. The level of statistical significance was defined as p < 0.05 and all statistical tests were 2-sided. Results are presented as the mean plus or minus the standard error, unless otherwise indicated.

Table 2 shows the mean and median levels for each variable, together with the range.

The effects of demographics on each emotional variable during conventional urodynamics are shown in Table 3. Sex, age and educational level did not have a significant effect on the variables. However, as income increased the degrees of bother (p = 0.008) and boredom (p = 0.011) during conventional urodynamics decreased.

Table 4 shows the effect of patient demographics on each variable during AUM. The patients' pre-procedural anxiety was not significantly different with respect to sex, age, educational level or income. With regard to gender and educational level, no significant differences were observed with respect to the degree of pain, shame, bother or boredom experienced during the procedure. In terms of age, the degree of bother experienced by patients 50 years of age or older was higher (5 versus 2.5, p = 0.030) than those less than 50 years old. In addition, as income increased, the degree of pain (p = 0.016), bother (p = 0.013) and boredom (p = 0.010) decreased. Other emotional aspects were not significantly different according to age and income.

Table 5 shows the mean levels of each variable for conventional video-urodynamics and AUM. The patient pre-procedural level of anxiety was significantly different (p < 0.05), and the degree of anxiety was higher for conventional urodynamics than for AUM (p = 0.045). However, the degree of boredom experienced during conventional urodynamics was lower than that experienced with AUM (p = 0.013). Other parameter values including pain, shame and bother, as well as the examiner's measurements (the degree of patient pain and patient tolerability) were found to not be significantly different for the two tests.

A significant correlation was found between the subjective pain score and the severity of pain as assessed by the examiner for both conventional urodynamics (r = 0.563, p < 0.001) and AUM (r = 0.586, p < 0.001). In general, patients tolerated the examinations extremely well. By using the stepwise method described earlier, the subjective pain score alone influenced the examiner-rated degree of intolerance during conventional urodynamics ([intolerance] = 0.418[pain] + 1.590; r = 0.498, p = 0.001), while all other emotional variables except bother were not significantly related to the degree of intolerance during AUM ([intolerance] = 0.244 [bother] + 1.233; r = 0.394, p = 0.007).

In response to the question of "If medically necessary, how willing would you be to return for this procedure?", a total of 74.4% and 84.6% responded with either "some," "considerably" or "very much" for conventional urodynamics and AUM, respectively. No patient chose the alternative of "not at all" for AUM, while 7.7% did for conventional urodynamics; patients' willingness to repeat the procedure was not significantly different.

A significant proportion of physicians and patients are concerned about the level of discomfort associated with urodynamic studies. However, although morbidities such as urinary tract infection and urinary symptoms after conventional urodynamic studies6,7 and AUM8 have been studied, no report exists in the literature to date concerning the emotional aspects of urodynamic studies. In the present study, we attempted to obtain detailed data enabling the quantitative evaluation of a patient's experience with conventional urodynamic studies and AUM using a questionnaire including a VAS. We gathered data on six categories including anxiety, pain, shame, bother, boredom, and intolerance.

The simple VAS proved to be a useful and valid measure of anxiety.13 Most patients awaiting an elective procedure experience anxiety,14,15 which is influenced by the uncertainty concerning the impending procedures, past experience, and the patient's coping style.13 Although Domar et al.15 suggested that anxiety was not correlated with the type of procedure, age or occupation of the patient, or with previous experience, other investigators have reported that age,16 sex16-18 and previous experience19 have significant impacts on anxiety. Therefore, we hypothesized that if patients awaiting a urodynamic study experience a high degree of anxiety, this difference should also be detectable by using a VAS since our patients had no prior experience with urodynamic studies. In the present study, despite the finding that patients showed more anxiety before a conventional urodynamic study than before AUM, the anxiety scores of patients awaiting a urodynamic study were low. These findings suggest that anxiety awaiting a minor procedure may differ from that associated with a major procedure.

Patients often experience discomfort, especially urethral pain, after a urodynamic study. In our study, 29 (75.6%) patients had a pain score of three or more, but no patient had a pain score greater than seven during conventional urodynamics. During AUM, 28 (70.0%) had a pain score of three or more and one patient reported a pain score of greater than seven. A significant correlation was found between the subjective pain score and the severity of pain as assessed by the examiner for both conventional urodynamics and AUM. Pain scores did not tend to correlate with pre-procedure anxiety scores in either study. We found that some demographics had an influence on emotional variables during conventional urodynamics and AUM. Interestingly, patients with higher incomes had lower bother and boredom scores during both conventional urodynamics and AUM. These findings suggest that the socioeconomic status of patients may play a role in the patient's emotions.

AUM differs from conventional urodynamics in terms of the equipment used, the type of urethral catheter, the bladder filling rate, the filling medium used, and the length of the test. All these factors may influence the discomfort that is associated with the procedure. The acceptability of the AUM may be due to the technique itself, during which patients are fully clothed and leakage is detected rather than visualized by the investigator. However, in this study many patients found both conventional urodynamics and AUM acceptable. Theoretically, any duration of monitoring may be used, but the potential benefits need to be offset against the disadvantages, which include discomfort and boredom for the patient. Thus, the time required for both conventional urodynamics and AUM may influence this finding, since the AUM takes longer.

It would be of value for physicians to recognize factors that influence the tolerability and successfulness of urodynamic studies. We analyzed the effects patients' emotions on their tolerance of urodynamic studies. In the current study, we evaluated patient tolerance using a questionnaire, and included both patient and examiner assessments. We found that patients with higher pain scores tended to lack tolerance for conventional urodynamic studies, while those with a high bother score showed intolerance to AUM, although most patients tolerated the procedures well and there was no difference among patients in terms of technical difficulty. In the present study, we assessed the same patients' experiences with the two procedures. This enabled us to compare the results and reduce individual variance. However, the potential limitation of the present study is that both procedures were not conducted in a random sequential manner, and this may have introduced a source of bias, especially in terms of the assessment of anxiety.

In the present study, although randomization has not taken place, conventional urodynamics showed a significantly higher level of anxiety than AUM, while the latter showed a significantly higher level of boredom than conventional study. Nonetheless, our data demonstrate that both conventional urodynamics and AUM are well tolerated.