Assessment of an electronic daily diary in patients with overactive bladder


  • Preliminary data from this study were first presented at the 30th Annual Meeting of the International Continence Society, Tampere, Finland, August 28–31 2000.

Dr P. Quinn, Pfizer Limited, Ramsgate Road, Sandwich, Kent CT13 9NJ, UK.



To assess the effectiveness of a portable electronic diary as a data collection device for overactive bladder symptoms, and to evaluate its level of patient acceptability compared with a conventional paper-based voiding diary.


Patients were identified through USA and UK hospital incontinence clinics. Patients were trained in the use of paper and electronic diaries before randomization, to complete either diary for 7 days. The diaries were then collected and, after a further training session, patients completed the other diary type for 7 days.


In all, 35 patients were recruited into the trial; overall, patients using the paper diaries (35) and electronic diaries (33) recorded similar data for the median number of incontinent episodes per week (8.2 and 7.0, respectively) and for the median number of significant leaks per day (0.4 and 0.5, respectively). However, the number of daily micturitions was slightly lower for the electronic than for the paper diary (7.3 vs 8.5, respectively). The frequency of urgency recorded in the electronic diary was higher than that recorded in the paper diary (5.8 vs 4.7). As 94% of patients found the electronic diary easy to use, and the electronic diary reflects real-time data entries, the electronic diary data may provide a more accurate reflection of patient symptoms.


We confirmed that the electronic diary is a novel method of collecting clinically relevant symptom data from patients with an overactive bladder. In addition, the ease-of-use ratings support the use of the electronic diary as a superior alternative to paper diaries, providing real-time data which can be rapidly analysed, and thus allowing a speedy review of data during ongoing clinical studies.


Overactive bladder (OAB) is a chronic illness that may occur with or without incontinence. Preliminary data from the National Overactive Bladder Evaluation programme suggest that its prevalence is similar in men and women [1]. However, the distribution of OAB with or without incontinence varies; in the USA, OAB with incontinence affects 9.3% of women and 2.6% of men, while OAB without incontinence has a prevalence of 7.6% and 13.6%, respectively [2]. Both types of OAB compromise the patients’ quality of life [3,4] and the impact of OAB should not be underestimated, as it affects more people worldwide than Alzheimer's disease (50 million and 37 million, respectively) [5,6].

The OAB is defined by the symptoms of urgency, with or without urge incontinence, usually with frequency and nocturia [7]. An OAB can be diagnosed using complex urodynamic tests but this may not be necessary in the typical patient with OAB [8]. Instead, OAB can be diagnosed from symptoms, which may be captured using paper-based frequency-volume charts (voiding diaries) to record the time of urination, frequency of urination, time of incontinence and volume of urinary loss. Voiding diaries have been recommended for use in assessing and quantifying ambulatory urodynamic monitoring [9], and paper diaries are now frequently used as a tool to assess outcome in patients with incontinence [10]. The ICS recently recommended that voiding time charts, frequency-volume charts and bladder diaries should be recorded for at least 2 days, so that the average voided volume, voiding frequency, day/night urine production and nocturia can be determined [11].

Although self-monitoring of voiding in patients with an OAB is regarded as a reliable way of obtaining information about the frequency of urination [12], compliance with paper diaries has recently been questioned. In a non-urological setting, data obtained from a National Cancer Institute study measuring pain experienced by patients showed that reported compliance with paper diaries was 90% (95% CI 86–94%). Patients had been asked to complete their diaries within 30-min around designated times, and on analysis actual compliance was only 11% (95% CI 8–14%). In comparison, the actual compliance with an electronic diary system was 94% (95% CI 92–96%) [13].

Specific studies in OAB have also questioned the reliability of paper diaries. A recent study found that paper diaries completed for 7 days are a reasonable option for accurately measuring the frequency of urinary symptoms in patients with incontinence, whilst 3-day and 28-day diaries were less reliable [14]. Furthermore, it was reported that compliance with recordings such as volume voided may decline after 72 h when patients are using paper diaries, as they may fail to properly record that variable [15].

A new electronic diary system, customised from the MiniDoc® unit (Araccel, UK) for capturing and processing patient data, has been developed for use by patients with OAB symptoms. In the present report, data are presented from a study assessing the effectiveness of the electronic diary as a data collection device for OAB symptoms, and its level of patient acceptability compared with a conventional paper diary.


Patients eligible for the trial were aged> 18 years and had OAB diagnosed by a physician. All patients were identified by attendance at hospital incontinence clinics in the USA and the UK, and had to be able to read, write and speak English such that they were capable of independently completing both the paper and the electronic diary. Patients with genuine stress incontinence were excluded from the trial unless they had OAB caused by detrusor instability as the primary diagnosis.

This study had a two-way cross-over design; patients were initially trained in the use of both types of diary and then randomly assigned to complete either the paper or the electronic diary for 7 days (period 1). At the end of this period the diaries were collected and a second training session given, after which patients were provided with the other diary for completion over a further 7 days (period 2).

The electronic diary was a customised version of the MiniDoc unit, shown in Fig. 1, a portable electronic data-capturing device designed for patients to input information about their condition and its management. The patient symptom data collected in the electronic diary were elicited via specific questions, which were presented in a logical flow depending on the option selected (Fig. 2). Data from the device can subsequently be downloaded for study and analysis, thereby giving greater accuracy and speed than with the paper diary. The paper diary used in this study was the standard tool commonly used to measure urinary symptoms [16] (Fig. 3).

Figure 1.

The MiniDoc® electronic diary.

Figure 2.

Question flow used in the electronic diary.

Figure 3.

The paper-based voiding diary.

Patients were asked to complete the diaries daily, recording events in ‘real time’ as soon as possible after their occurrence. The primary endpoints for analysis were frequency/volume efficacy variables, recorded using both types of diary. The following data were recorded; number of incontinence episodes/week, mean number of micturitions/day, mean volume of urine/void, mean number of nocturnal awakenings for OAB, mean number of incontinence episodes (‘significant leaks’) requiring a change of clothing or pads, mean daily frequency of urgency, mean daily severity of urgency (on a four-point scale with 0 = mild, 3 = severe), and a 100-mm visual analogue scale (VAS; 0 = mild, 100 = severe).

At the end of each period, patients rated the ease of use of the diary on a nine-point scale (1 = not at all easy, 9 = extremely easy) and were interviewed, using face-to-face questionnaires and free responses, to ascertain their opinions of the diaries.


For the purposes of comparison, the median frequency/volume efficacy data were split by diary type and by both diary type and age group (< 65 and ≥ 65 years). Ease-of-use ratings for both types of diary were tabulated for comparison. Summary data for the two methods of recording the mean daily severity of urgency (four-point scale and VAS) were prepared graphically. The study was not powered to detect differences between the types of diary.


Thirty-five patients (32 women and three men) were recruited into the trial from three UK incontinence clinics (15) and two USA clinics (20). The randomization process resulted in two unequal groups (21 vs 14 patients), although the number of patients receiving each diary was the same; demographic data are shown in Table 1. Data for assessing the paper diaries were available from all patients but for the electronic diaries were available from only 33; two were excluded for attempting to input information retrospectively, which resulted in a large allocation of data to one day. However, these patients were not excluded from the paper diary analysis, as there was no evidence to support the possibility that they had added data to the paper diaries retrospectively.

Table 1.  The patient's characteristics
then paper
Paper then
No. of patients211435
Mean (range) age, years57 (30–88)58 (36–77)58 (30–88)
Age group (years), n (%)
25–44  4 (19)  2 (14)  6  (17)
45–6410 (48)  7 (50)17 (49)
≥  65  7 (33)  5 (36)12 (34)
Country of origin, n (%)
UK10 (48)  5 (36)15 (43)
USA11 (52)  9 (64)20 (57)


Errors, including incomplete times, inconsistent timing of events, incomplete events (e.g. micturition recorded but no volume data) and incorrect completion of VAS scales (thus invalidating the scores) were detected in 80% of paper diary entries. However, such errors were not possible in the electronic diaries, as patients were prompted with questions, and responses were provided in a more structured format. Patient claims that data were entered into the diaries within 2 h of the event occurring were verified by date/time stamping in 73% of cases for the electronic diary, but could not be confirmed for the paper diaries.


Frequency/volume data were comparable whether collected by the electronic or paper diary (Table 2). Similarly, when categorised by age (< 65 and ≥ 65 years) most data were comparable between the diary methods (Table 2). However, there were slightly fewer daily micturitions for the electronic than the paper diary (7.3 vs 8.5, respectively), which was more pronounced in those aged ≥ 65 years (Table 2), suggesting that one method provided a less accurate record of the data. Importantly, the number of nocturnal awakenings were similar between electronic and paper diaries.

Table 2.  The median values for frequency/volume efficacy variables, and urinary symptoms (in younger and older patients)
  • *

    Two patients excluded because of spurious data entries;

  • † electronic diary 32, paper diary 33;

  • ‡ 20;

  • ¶ 22;

  • §

    § 11.

Urinary symptoms (medians)
No.  33*  35
No. of incontinence episodes/week    7.0    8.2
Micturitions/day    7.3    8.5
Frequency of urge/day    5.8    4.7
Volume per void, mL154.6138.1
‘Significant leak’ per day    0.5    0.4
Nocturnal awakenings due to OAB    1.0    1.3
By age group (< 65/≥ 65 years)
No.  21/12  23/12
No. incontinence episodes/week    7.0/7.6    7.0/8.9
Micturitions/day    7.8/5.8    8.7/8.2
Frequency of urge/day    6.5/4.5    5.7/3.3
Volume per void, mL 171.8/141.3156.1/130.6§
‘Significant leak’/day    0.3/0.7    0.3/0.6
Nocturnal awakenings due to OAB    1.0/1.4    1.0/1.5

Figure 4 shows the mean severity of urgency (VAS) categorized into mild, moderate, marked or severe (four-point scale). Most patients recorded moderate symptoms in both the electronic and paper diaries, although more entries were recorded in the electronic than in the paper diaries (182 and 155 entries, respectively).

Figure 4.

The mean daily severity of urgency (VAS) categorized as mild (open bars), moderate (green bars), marked (red stippled) or severe (red hatched), as recorded using the electronic and paper-based diaries.


Most patients found the electronic diary very easy to use (Table 3); only 6% rated the electronic diary as not at all easy to use and none reported difficulties in understanding how to use the paper diary. When specifically asked for their comments on the instructions for the electronic diary, 10 patients were initially more wary of the electronic than the paper-based diary, feeling that the tuition could have been simpler or clearer.

Table 3.  Ease of use ratings for electronic and paper voiding diaries (mean values)
Ease-of-use ratings*Electronic diary (n=33)Paper diary (n=35)
  • *

    Nine-point scale (1 = not all easy, 9 = extremely easy);

  • † two patients excluded due to spurious data entries

Daily use7.38.1
Log in7.6
On-screen menu8.1


The present results show that the electronic diary is an effective tool for recording urinary symptom data in the setting of a clinical trial of OAB. Urinary symptom data collected electronically were mostly comparable with data collected using the paper diary, suggesting that the electronic diary is an appropriate alternative to a paper-based method for assessing symptoms of OAB. The most pronounced difference in the recordings in the two diaries was the number of micturitions per day (5.8 and 8.2, respectively) in patients aged ≥ 65 years. As the ease-of-use ratings were high for both types of diary, it is unlikely that patients did not enter the electronic diary recordings. Therefore, the differences in the data may be attributed to the real-time recordings of the electronic diary. In addition, as there were no data errors in the electronic diary, it is possible that the electronic diary data may reflect more accurate recordings of the number of micturitions per day than the paper diary.

Voiding diaries can be used to distinguish between urge and stress incontinence [17] and are useful for monitoring a patient's OAB symptoms at baseline and after therapeutic intervention [16]. Urgency is characterized by a strong, sudden urge to void [18], and the ICS recently confirmed that it is the primary symptom of OAB [7]. The present data suggest that the electronic diary collects information about urgency more effectively than a paper diary, as more entries were recorded in the electronic than in the paper diaries. It is possible that prompting from the electronic diary meant that patients made more accurate recordings of urgency, and because urgency is a warning symptom rather than an endpoint, patients are likely to forget to make a diary record unless prompted.

As the concept of electronic voiding diaries is relatively new in the urological setting, there are few data with which to compare our findings. The electronic diary system tested by Rabin et al.[19] provided more information than a paper diary, suggesting that electronic diaries might enable physicians to track a patient's symptoms more effectively. However, the diary was criticised for not recording voided volume, and it was suggested that including this variable might compromise the patients’ ability to use a computerized system (although no reasons were given as to why the authors felt this would be the case) [16]. The present study showed that, even when voided volume is included, an electronic diary method is as effective as a paper diary. Electronically collected data has several advantages, including rapid transfer to a computer (which can be via a modem to a central server), easy formation of databases and quick resolution of queries, all features that reduce the time required to analyse the results, and rapid review of data during ongoing trials. Depending on how the study has been devised the data can be viewed via a secure website.

To conclude, the comparability of the data collection methods suggests that the electronic diary is an appropriate alternative to a paper-based method for assessing symptoms of OAB, while ease-of-use ratings appear to support the electronic diary as an acceptable alternative to paper diaries. The electronic diary had no data errors and the real-time recordings obtained may more accurately reflect patient symptoms. Data from other trials with electronic diaries showed that they are a more accurate method for recording patient symptoms, as actual compliance rates are higher than with paper diaries [13]. In addition, data can be collected and analysed more swiftly using electronic than paper diaries, thus helping to shorten the time needed to bring new and effective medicines for OAB into use. The results obtained in this study support the wider use of electronic diaries in clinical trials designed to evaluate new treatments for OAB.


overactive bladder


visual analogue scale.