Evaluating the Usability of Mobile Application-Based Digital Therapeutics for Overactive Bladder Management: Pilot study

Abstract

Purpose : This study aimed to assess the usability and functionality of mobile application-based digital therapeutics (DTx) for overactive bladder (OAB) management. OAB affects approximately 43 % of women and 36 % of men over 40 years of age, significantly reducing the quality of life and inflicting economic and social burdens. Although behavioral therapy is a key non-pharmacological intervention, low adherence limits its effectiveness. DTx offers a scalable solution to enhance adherence and complement traditional treatments. Using mobile applications, wearables, and interactive tools, DTx provides evidence-based interventions such as bladder training, pelvic floor muscle exercises, and cognitive-behavioral techniques. Although early studies highlighted the potential of DTx to improve patient outcomes and engagement, further research is needed to validate its short-term efficacy and integrate it into routine OAB management. In this study, we developed a mobile application-based DTx tailored for patients with OAB. Methods : A mobile device application for OAB management was developed, and its feasibility and usability were assessed. Five female participants were randomly recruited to use the app for seven days. The application features two primary modes: "holding mode", which employs cognitive distraction techniques to reduce urgency, and "daily mode", which facilitates pelvic floor muscle training. Additional functions include urine output and fluid intake monitoring, statistical data visualization, an educational module providing exercise guidelines, and OAB-related information. After the study period, usability and feasibility were evaluated through individual post-study debriefing sessions using the mobile application rating scale (MARS), user experience questionnaires, and semi-structured interviews. Results : Five female participants (mean age: 50.40±2.73) used the app for a week and provided feedback. In the pilot study, participants found "holding mode" effective for short-term symptom relief, but patient feedback highlighted the need for enhanced long-term engagement and simplified features. Overall satisfaction was moderate, engagement-related aspects were rated low, and interest in purchasing the application was minimal. Conclusion : Despite some challenges, this application can be a supportive tool for OAB behavioral therapy bycombining urgent relief with long-term behavioral modifications. Further research is required to refine its features, validate its clinical utility, and develop scalable digital therapeutic solutions for OAB management.

Ⅰ. Introduction

Overactive bladder (OAB) is a chronic urological condition characterized by urinary urgency, often accompanied by frequency and nocturia, with or without urge incontinence (Abrams et al., 2002). It is a prevalent disorder that significantly impairs the quality of life, affecting approximately 36 % of men and 43 % of women over the age of 40, with the incidence intensifying in older populations (Scarneciu et al., 2021). This condition not only causes physical discomfort but also leads to sleep disturbances, anxiety, depression, and reduced social and physical activity. OAB also imposes substantial economic and social burdens, including increased healthcare costs and reduced workplace productivity (Enemchukwu et al., 2022; Scarneciu et al., 2021). This underscores the urgency of developing innovative and individualized management strategies to address these multifaceted challenges.

To manage symptoms of OAB, the European Association of Urology (EAU) guidelines strongly recommend cognitive behavioral therapy and pelvic floor muscle training as first-line therapies before considering medication. Additionally, they strongly advocate for the use of voiding diaries and overactive bladder symptom score (OABSS) questionnaire for accurate diagnosis (Nambiar et al., 2022).

Digital therapeutics (DTx) have emerged as evidence-based medical interventions that utilize digital tools, such as mobile applications and software platforms, to manage, prevent, or treat diseases effectively (Sooknarine et al., 2024). DTx can provide behavioral interventions, including bladder training, pelvic floor muscle exercises, and cognitive-behavioral techniques. Early studies have demonstrated significant improvements in symptom management and quality of life through long-term digital therapy programs (Sooknarine et al., 2024). However, further research is needed to validate their short-term efficacy and integrate digital therapy into clinical practice of OAB.

We developed a digital therapeutic mobile application for managing overactive bladder (OAB) symptoms. This application employs attention-shifting techniques for urgent symptom relief, guides pelvic floor muscle training, and provides insights into voiding patterns to support behavioral modifications. The purpose of this pilot study is to evaluate the usability and feasibility of the application by a standardized tool, to ensure it effectively meets the immediate symptom management needs of users and promotes long-term improvements through sustained engagement.

Ⅱ. Methods

1. OAB app development

The prototype version of the “OAB” app, was independently developed in Korea, in Korean language as part of a digital therapeutic approach for OAB management. OAB was designed by a team of urologists to support both male and female patients experiencing OAB symptoms. The application was custom-built and optimized for usability testing. It was not publicly available and was exclusively accessible to study participants for research purposes. It includes two distinct modes: "Holding mode" and "daily mode" and incorporates functions for tracking urine output and fluid intake, along with a dedicated page for displaying the user's statistical results. Additionally, the app provides an educational exercise guideline and detailed information about OAB, including the importance of performing the recommended exercises, all accessible to users (Fig 1).

Fig 1. Different functions of the prototype version of the app, highlighting key features and user interface elements

Holding mode: On the home page of the app, there is a large button resembling an emergency button, featuring the "holding mode" option that initiates a 15-second pelvic floor muscle contraction exercise, which can be performed in any position. This is followed by a mini-game lasting 45 seconds, designed to combine attention-shifting tasks with physiological responses, such as an increased heart rate. In the game, users must quickly block water leaking from cracks while avoiding bombs that act as distractions. Successfully blocking cracks earns points, while touching bombs results in negative scores. The game progressively increases in difficulty as the speed of appearing cracks intensifies.

Daily mode: The exercise protocol was designed by exercise physiologist researchers as a progressive pelvic floor muscle training (Table 1) and included an algorithm to adjust the difficulty level based on the user’s rating scale after completing the routine for each position. Users were instructed to perform the exercise at the same time each day, completing the routine in all three positions (sitting, standing, and lying) within a day was meant to be 1 set. The protocol required users to complete three sets of 5~15 repetitions per day, with a 5~10 second contraction hold and a 10-second rest between repetitions (Burgio et al., 1998; Fitz et al., 2017; Voorham et al., 2017).

Table 1. Protocol for progressive pelvic floor muscle training

s; second

The daily exercise consisted of three phases: concentric contraction, isometric contraction, and eccentric contraction of the pelvic floor muscles. A bell sound, accompanied by an auditory guide, signalled the start of each phase, providing a cue that allowed participants to set the phone aside and focus on the exercise more easily. Users could select their starting position and proceed through the routine accordingly. To guide the exercise, a visual aid in the form of a circle was displayed in the app, which expanded and contracted to help users control their pace. Users were supposed to slowly contract their pelvic floor muscles, following the movement of the circle instead of contracting all at once. After reaching full contraction, they were to hold the contraction before gradually relaxing their muscles in the final phase. Positive feedback was popped up during the rest periods between sets to encourage and motivate them. Messages such as “the more you work, the better results you will get”, “you are improving little by little every day”, and “feel the big change through short exercises!” were shown randomly to maintain engagement and boost user confidence. According to the user’s rating (1= easy to 5= hard), the following adjustments were set for the next exercise routine: if the rating is 1 (very easy), the difficulty level is upgraded by one; if 2 (easy), it is upgraded by one level; if 3 (neutral), the level remains the same; if 4 (difficult), it is downgraded by one level; and if 5 (very difficult), it is downgraded by two levels.

Void tracker: Users can input the time and volume of voided urine, with each entry followed by a prompt asking whether holding the urine was challenging. If the user selects "hard" as an answer, a 5-point rating scale is displayed to evaluate the level of difficulty. Additionally, the user is asked whether urinary incontinence occurred.

Fluid intake: users can log the time and volume of fluid intake, display as regular cup icons, and specify if the drink contains caffeine.

Chart: The results of app usage, including frequency and duration of urination, volume of urination, water intake, exercise performance, and session success rate, are presented to users in chart form. These charts can be customized to display data on a weekly or monthly basis.

2. Participant recruitment and usability evaluation

After developing the prototype version of the app, 5 female participants aged 45~54 were randomly recruited through a recruitment poster inside the campus to assess the app's usability and user experience (UX). Eligible participants were those available for a 7-day app usage period and willing to engage in pelvic floor exercises. This evaluation focused solely on the prototype and UX, rather than patient recruitment. The primary objective was to gather feedback on the app's overall functionality and interface using the mobile application rating scale (MARS), with a UX questionnaire designed to focus specifically on the "chart" features and “holding mode”. This evaluation was conducted during a brief intervention, allowing users to share their opinions on these key elements.

Mobile application rating scale (MARS): We used Korean version of the MARS tool to assess the quality of app. MARS demonstrated excellent internal consistency and moderate to good inter-rater reliability (ICC: 0.45~1.00), confirming it as a valid and reliable tool (Hee Ko et al., 2022; Stoyanov et al., 2015; Terhorst et al., 2020). This tool consists of 23 evaluation criteria grouped into five domains, with each criterion rated on a scale of 1 to 5, where 1= inadequate, 2= poor, 3= acceptable, 4= good, and 5= excellent. The five domains provide a comprehensive framework for assessing various aspects of app quality: (1) Engagement, which evaluates the app's entertainment value, customization features, and interactivity, including feedback, reminders, and notifications; (2) Functionality, which examines ease of use, screen transitions, intuitive design, and overall performance; (3) Aesthetics, which assesses graphic design, visual appeal, and stylistic consistency; (4) Information, which focuses on the quality and credibility of the content, including text, metrics, and references; and (5) Subjective quality, which considers whether the app is recommendable to potential users, its value for money, expected frequency of use, and overall star rating (Stoyanov et al., 2015).

After collecting the MARS evaluations from participants, domain mean scores were averaged to determine the total MARS score, representing the app's overall quality.

UX Questionnaire: We developed a questionnaire and interview section to evaluate various aspects of the app's user experience (UX) and user interface. The goal was to collect feedback on how users perceive and interact with the app's features, with a particular focus on their engagement, enjoyment, and overall satisfaction. This process aimed to identify areas for improvement in both the UX and UI design. Participants rated each aspect on a scale from 1 (very poor) to 5 (very excellent). For time duration questions, 0 indicated "very long" and 5 indicated "very short".

Ⅲ. Results

Five female participants, with a mean age of 50.40±2.73, used the app for a week to provide detailed feedback. The results of the UX questionnaire and MARS evaluation are presented as mean (SD). Participants were instructed to use the app's "holding mode" when experiencing the urge to urinate, allowing them to simulate the sensation in a realistic context.

MARS evaluation: Subscale scores, including engagement, functionality, aesthetics, and information, along with the overall quality score and subjective quality score (satisfaction), are presented in Table 2. While participants rated the overall app as moderately satisfactory (above the midpoint), specific items within the engagement subscale, such as "customization" (2.80±0.84) and "interactivity" (2.60±0.89), received ratings below the midpoint. Additionally, the intention to purchase the app in its current form was low, with a mean score of 2.00±0.82.

Table 2. Overall evaluation of the app using MARS tool (n= 5)

SD; standard deviation

UX Questionnaire: The results of the UX questionnaire assessing the app's "holding mode" and "chart" features are presented in Table 3. Key scores include item 1 (entertainment: 2.80±1.10), item 2 (engagement: 2.80±0.96), and item 5 (game duration: 2.80±0.45) were rated lower than the midpoint compared to other items. When participants were asked to describe any issues or suggest areas for improvement, feedback for the "holding mode" included "suitable for holding utility" and "interference with holding due to leakage". For the "chart" tab, participants noted "difficulty understanding the graph" and "statistics are not immediately clear".

Table 3. Evaluation of the chart and holding mode section of the app using the MARS tool (n= 5)

SD; standard deviation

Participant feedback on app features: we gathered participants' opinions on the app, including any aspects not covered by the questionnaire, through a comprehensive interview process.

Regarding the game in the "holding mode" participants noted positive aspects, such as "it seems effective when holding urine" and "it is manageable to hold during urgency" However, some highlighted issues like "The sensation of leakage made the urge worse". Opinions about the app's features varied. While the "holding mode" was generally effective, the game's initial appeal diminished over time, and its overall effectiveness was unclear to some participants. Suggested improvements included allowing the recording of voiding and intake data from previous days, offering actionable guidance based on these records, and addressing the difficulty in estimating urine volume. For the "chart" feature, participants reported challenges in understanding the graphs and expressed that the statistical data were not immediately clear. These findings provide valuable insights for further refinement of the app.

Regarding exercise feature, participants provided various opinions on the app during the evaluation. They appreciated the sound of the bell, finding it pleasant and suitable for exercising while doing other tasks. However, some participants suggested the addition of a "vibration mode" for situations where audio cues like "tighten" or “loosen” were uncomfortable. There was also feedback that viewing the "tighten" word or "tightening circle" on the screen while exercising in public made some users feel self-conscious, and they preferred a vibration mode for more privacy. Participants felt that increasing the number of sets was unnecessarily burdensome and suggested keeping the number of sets fixed while increasing repetitions or time. The motivational comments during exercise were well received, and the three posture options were appreciated. Some users recommended distinguishing the "start" button with different colors to improve clarity during the initial exercise explanation.

Participants shared several opinions about the app’s chart feature. They found the graph difficult to understand, with the statistics not easily visible at a glance. Even after closer inspection, the information remained unclear. While the chart was generally deemed acceptable, participants felt it would be more useful if it focused on the current status and offered actionable guidance on what to do next. They also expressed a desire for improvement suggestions and were unsure of the chart’s purpose, recommending a simpler design for better clarity.

Ⅳ. Discussion

DTx are transforming healthcare by providing evidence-based interventions through digital platforms such as mobile applications, wearables, and software (Wang et al., 2023). This study assessed the feasibility of a mobile application-based digital therapeutic for OAB management in a pilot study (n= 5). As the study focused on usability and feasibility rather than clinical effectiveness, randomization and blinding were not implemented. The findings will guide modifications to enhance the app’s functionality before a larger randomized controlled trial (RCT) is conducted to evaluate its clinical impact. The app, featuring "holding mode" for urgency suppression and "daily mode" for progressive pelvic floor muscle training, received generally positive feedback in terms of usability and functionality. Unlike previous studies that primarily focus on long-term behavioral modifications, our app uniquely incorporates the "holding mode" a feature designed to provide short-term symptom relief through attention diversion and urgency suppression. Participants reported that this mode was particularly effective during episodes of urgency, combining interactive mini-games with physiological engagement to reduce discomfort. While the MARS results indicated moderate overall satisfaction, high scores in functionality and ease of use underscore the app's practical value. These findings highlight the app's potential as a supportive tool for behavioral therapy in OAB management, paving the way for further refinement and large-scale clinical validation. However, some limitations were identified. Feedback highlighted challenges in maintaining long-term engagement with the "holding mode" as the game's novelty diminished over time. Additionally, participants noted that the "chart" feature was difficult to interpret, and the statistical data lacked immediate clarity. These issues suggest that further refinements, such as improving visual designs, simplifying data presentation, and enhancing game variety, are necessary to maximize the app's usability and effectiveness. Despite these limitations, the app's high functionality and ease-of-use scores underscore its practical value as a supportive tool for behavioral therapy in OAB management.

Globally, DTx have demonstrated efficacy in managing chronic and behavioral conditions. For example, pear therapeutics' reSET-O for opioid use disorder and Somryst, a cognitive-behavioral therapy-based app for insomnia, have received FDA approval, highlighting their clinical validation and potential for widespread use (Huh et al., 2022). Studies have shown that DTx can achieve adherence rates of up to 80 %, significantly outperforming traditional therapies, such as pharmacological treatments, which often see adherence rates below 50 % (Wang et al., 2023). In a systematic review of digital cognitive-behavioral therapy for insomnia (dCBT-I) interventions, including apps like Sleepio, studies using the insomnia severity iIndex (ISI) as an outcome measure demonstrated significant reductions in insomnia severity. Digital interventions showed a mean effect size of −0.89 (95 %CI: −1.00, −0.78) compared to education-only control groups and −0.94 (95 %CI: −1.15, −0.73) compared to no-intervention controls, underscoring their efficacy in reducing insomnia symptoms (Jeon et al., 2023).

Pelvic floor muscle training is recommended as the first-line treatment for overactive bladder, as well as stress, urge, and mixed urinary incontinence (Gormley et al., 2015). It is widely recognized as a behavioral training method that aims to prevent or treat urinary incontinence and other pelvic floor disorders through three key mechanisms: enhanced pelvic floor muscle strength, improved awareness of timing, and strengthened core muscles (Sheng et al., 2022). Previous studies have shown that pelvic floor muscle training is effective in reducing urinary incontinence in both men and women (Cho & Kim, 2021), as well as in individuals recovering from organ prolapse following surgery (Basnet, 2021; Jamrasi et al., 2018). Pelvic floor muscle training is recommended as a behavioural treatment for OAB by several guidelines, including those from the National Institute for Health and Care Excellent (NICE) (NICE, 2021), the American Urological Association (Gormley et al., 2015) and the European Association of Urology (Nambiar et al., 2018). Studies have shown that pelvic floor muscle training significantly improves outcomes in patients with OAB, as evidenced by improvements in the pelvic floor impact questionnaire (PeLFIs), King's health questionnaire (KHQ), voiding diary, and 24-hour pad test (Voorham et al., 2017). The training led to a reduction in urinary loss, nocturia, and discomfort related to urinary symptoms, as assessed by the overactive bladder questionnaire (OAB-V8) (Fitz et al., 2017). Furthermore, an 80.7 % reduction in incontinence episodes was reported, with patients noting a perceived improvement in symptoms (Burgio et al., 1998).

Despite its benefits, the effectiveness of behavioral therapy is often limited by low adherence rates, which can drop to 32 % after 12 months (Enemchukwu et al., 2022). Key barriers include the time-intensive nature of interventions, lack of proper guidance, and challenges in maintaining long-term engagement. DTx present a scalable solution to enhance adherence and improve outcomes. Pharmacological treatments for OAB, such as antimuscarinics and β 3-agonists, also face significant limitations due to side effects like dry mouth and constipation, leading to adherence rates as low as 15~40 % after the first year. Up to 85 % of patients discontinue antimuscarinics within a year, largely due to tolerability issues and inadequate symptom relief.

OAB digital therapy is gaining recognition as a complementary approach to traditional OAB treatments, addressing limitations in adherence and engagement. DTx leverage mobile applications, wearables, and interactive tools to deliver behavioral interventions such as bladder training, pelvic floor muscle exercises, and cognitive-behavioral techniques. Studies have demonstrated the efficacy of these tools in improving patient outcomes. For instance, a mobile application integrating pelvic floor muscle training and urgency suppression techniques showed significant reductions in urgency episodes and improvements in the quality-of-life scores, such as the overactive bladder questionnaire (OAB-q). In one study using the "CeCe" digital conversational agent, participants experienced significant symptom improvement, with median ICIQ-OAB-QoL scores decreasing from 62 to 32 (p<.001) over 8 weeks (Sheyn et al., 2024). Nocturia episodes dropped from a median of 2 to 1 (p= .030), and urgency urinary incontinence episodes decreased from 2 to 0 (p= .040). Another pilot study utilizing a digital behavioral therapy app reported a reduction in daily voiding frequency from 10.19 to 6.71 times (p= .017) and incontinence episodes from 10 to 3.57 (p<.05) (Sooknarine et al., 2024). Participants rated these apps highly for usability and effectiveness, with up to 70 % recommending them as adjunctive treatments. These findings highlight DTx's potential to enhance adherence, accessibility and patient empowerment, offering a complementary approach to traditional OAB management while managing symptoms effectively and improving overall quality of life.

Ⅴ. Conclusion

This study demonstrates the potential of mobile application-based digital therapeutics for OAB management by combining short-term urgency relief through attention diversion techniques with long-term behavioral modifications. The unique "holding mode" proved effective in alleviating symptoms, while features like progress tracking enhanced user engagement. Despite these promising results, challenges such as sustaining long-term engagement and improving usability remain. Future research is needed to validate these findings in larger populations and integrate digital therapeutics into routine clinical practice, offering a scalable and patient-centered solution for OAB management.