Urolithiasis, or urinary calculi (UC), is emerging as a significant global health crisis, affecting individuals of all ages and genders. The prevalence of UC has been increasing worldwide over the past decades [1]. Estimated incidence rates are 7%‐13% in North America, 5%‐9% in Europe, and 1%‐5% in Asia [2]. In low-income countries, up to 25% of the population can be affected, often with fatal outcomes due to inadequate urological care [3]. In China, the prevalence of nephrolithiasis is around 5.8%, exceeding 10% in the southern region [4]. Meanwhile, the high recurrence rate of UC poses a significant challenge, with approximately 10%, 30%, and 50% of individuals experiencing recurrence at 1 year, 5 years, and 10 years, respectively [5-7]. The financial burden of UC is substantial, with yearly medical expenses estimated at 10 billion dollars in the United States and US $695.51 million in Europe [8,9]. Predictive models indicate that the high prevalence and recurrence rate will lead to a 25% increase in health care costs over the next 50 years [10]. This makes UC one of the most expensive urological diseases, highlighting the urgent need for better understanding and management of this condition.

The occurrence of UC is influenced by a variety of environmental, climatic, and dietary factors. Environmental and climatic conditions, particularly in hot climates, can contribute significantly to water loss and water quality issues. High temperatures often lead to increased perspiration, which in turn reduces overall water levels in the body. This dehydration can concentrate the urine, increasing the likelihood of stone formation. Additionally, water quality, specifically the levels of sodium and other minerals, plays a crucial role in this process [11,12]. Dietary habits are another critical factor in the development of urinary stones. Insufficient water intake is one of the primary dietary risk factors, as it leads to more concentrated urine, which facilitates the crystallization process. Poor dietary habits, such as the prolonged consumption of oxalate-rich foods—like spinach, nuts, and chocolates—significantly elevate the propensity for developing calcium oxalate stones [13]. High-sugar and high-fat diets further exacerbate this risk by influencing urinary elimination processes, making the urine more conducive to stone formation [14]. These risk factors highlight the important role of nurses in implementing targeted hydration protocols and dietary interventions to mitigate stone recurrence.

The European Association of Urology and the American Urological Association both strongly emphasize the importance of increasing fluid intake to prevent urinary stone formation. Research indicates that increasing fluid consumption stands out as a simple and economically feasible way to lower the risk of stone formation [15]. Then, McCauley et al [16] discovered that patients tend to be more open to increasing fluid intake than adopting other dietary or pharmaceutical therapies. Yet, Khambti et al [17] identified a challenge, noting that only about half of patients with urinary stones adhere to hydration recommendations, as determined through 24-hour urine output tests. Building on this, further research elucidated the underlying causes: at first, patients might not know or remember to drink enough; then, some dislike the taste of water or do not feel thirsty; and finally, the need for frequent voiding or workplace factors gets in the way [16]. Other research backs this up, showing that forgetfulness or not realizing their need for hydration plays a big role in poor fluid habits [18,19]. Therefore, enhancing adherence to fluid intake recommendations offers substantial benefits, including reduced health care expenditure through lower incidence of urinary stones and associated costs, improved public health outcomes, and an elevated quality of life (QoL) by decreasing the frequency and severity of symptoms.

Digital therapeutic interventions (DTx) deliver evidence-based, software-driven solutions via mobile apps, wearables, and web platforms to manage conditions. Unlike wellness tools, DTx is clinically validated, often regulated, and designed for measurable health outcomes [20]. By 2026, the global mobile app market was expansive, with approximately 4 million apps available on the Apple App Store and Google Play, reflecting the vast potential of digital health tools [21]. However, conventional mobile apps face significant barriers to widespread adoption, such as complex development processes, protracted timelines, and substantial financial investment, which often limit their scalability and accessibility in clinical settings. In contrast, WeChat applets, which require no installation and are integrated into China’s predominant social media platform, facilitate seamless, on-demand access, effectively addressing technical barriers and offering distinct advantages by enhancing user convenience and minimizing operational challenges. With over 1.4 billion monthly active users, WeChat has a vast reach and engagement, making it a widely used communication tool in China. Using WeChat’s existing infrastructure, the applets simplify the process by reducing the need for extensive coding and platform-specific adaptation and allow individuals to access them instantly. The significance of WeChat in health care has been amplified by its rapid adoption during the COVID-19 pandemic, which catalyzed its integration into various medical contexts, from telemedicine to patient education, markedly improving care quality [22,23]. Notably, the feasibility of using WeChat to enhance adherence to prevention strategies has been demonstrated among multiple chronic diseases [24]. WeChat-based DTx overcomes conventional mobile app barriers and drives health care innovation by enhancing patient adherence and care quality across diverse medical contexts, including chronic disease management and preventive strategies.

Previous studies have highlighted the limitations in the current landscape of DTx for fluid management and urinary stone prevention. Stevens et al [25] noted that many apps lack the support of medical professionals, leading to the dissemination of potentially false information and inaccuracies that could negatively impact patient health. This underscores the importance of involving medical professionals in the development and content review of these apps to ensure their reliability and clinical validity. The advent of digital technologies, such as wearable devices and intelligent water bottles, has introduced new methods for monitoring water intake and preventing urinary stones. However, the effectiveness of these devices is highly dependent on the practicality of their use. For instance, patients may not always have access to smart bottles in all settings, which can lead to incomplete fluid intake records. Karagöz and Sarıca [26] further pointed out that the high cost and inconvenience associated with these devices may deter long-term patient compliance, highlighting the need for more cost-effective and user-friendly solutions for fluid intake notification. A review of the literature reveals that most published studies are small-scale, single-arm pilot interventions lacking robust controlled trials designed to evaluate long-term effectiveness and adherence. Moreover, Philip-McKenzie et al [27] analyzed 51 apps from the Apple and Google Play Store and found that none of the apps measured urine volume and color, and only 1 provided medical advice or educational content regarding the consequences of poor hydration. This reveals a substantial gap in the provision of comprehensive medical advice and education within these apps to improve patients’ recognition of disease severity. Furthermore, Winoker et al [28] highlighted the scarcity of evidence supporting the benefits of mobile health (mHealth) interventions in urological care and emphasized the need for more rigorous research to validate the effectiveness of these technologies. Karagöz and Sarıca [26] also recommended that future research should focus on the practicality, security, efficacy, and overall benefits of these apps in preventing stone recurrence.

This study aims to investigate the efficacy of the WeChat-Based Applet Fluid Intake Reminder (WAFIR) in improving fluid intake among postoperative patients with UC compared to standard care, with the ultimate goal of reducing stone recurrence and enhancing patient well-being. The specific objectives are to quantify changes in daily fluid intake and urine output, evaluate its effect on the QoL, and determine its influence on readmission rates, recurrence rates, and eHealth literacy over the follow-up period. We hypothesize that patients receiving WAFIR exhibit statistically significant differences in 24-hour urine output (mL), fluid intake (mL/24 hours), QoL (Wisconsin Stone Quality of Life Questionnaire [WISQOL] score), eHealth literacy (Electronic Health Literacy Scale [eHEALS] score), or urinary stone recurrence rates (3-month follow-up) compared to those receiving usual care.

This research has achieved notable advancements in assessing the efficacy of a nurse-led digital health intervention, WAFIR. The development of WAFIR, conducted in collaboration with a software developer, was finalized in February 2025, establishing a technological platform for the study. Recruitment, a critical initial stage, was fully completed, with all 148 participants enrolled from a tertiary hospital in Mainland China between March 1, 2025, and June 27, 2025, exclusively during the predischarge hospitalization period. Baseline data collection (T0) was completed by June 30, 2025, providing a solid baseline for longitudinal analysis. Follow-up assessments at the 1-month mark (T1) were finalized on July 31, 2025, while the 3-month follow-up (T2) is set to conclude in October 2025, aligning with the present date. Subsequent data analysis is scheduled for completion by December 2025, with dissemination of results planned through academic conferences and peer-reviewed publications throughout 2026.

This study represents, to our knowledge, one of the first RCTs to assess a nurse-led, WeChat-based DTx specifically tailored for UC management, addressing a critical gap in mHealth interventions that often lack medical oversight or clinical validation. The primary outcomes of this study are to evaluate the effectiveness of the WAFIR in improving fluid intake and urine output among postoperative patients with UC. We hypothesize that the WAFIR intervention, combining fluid intake reminders, urine color monitoring, fluid and urine tracking, and evidence-based educational content, will significantly enhance adherence to hydration recommendations compared to standard care, potentially lowering recurrence rates and improving patient-reported outcomes such as QoL (via WISQOL), eHealth literacy (via eHEALS), and mental health (via PHQ-9).

This study used face-to-face and telephone interviews to collect data. However, interviews are subject to limitations, including the absence of visual cues (particularly in telephone interviews), reduced ability to observe contextual details, and potential difficulties in eliciting sensitive information, which may affect data quality [45]. The primary outcome, 24-hour urine volume, is required to be collected. However, previous studies indicate challenges in obtaining precise 24-hour urine samples due to poor patient compliance, which may result in incomplete or abandoned collections stemming from the complex or inconvenient nature of the process, as well as deviations from the 24-hour collection period. To enhance the measurement accuracy of 24-hour urine collection, it is crucial to improve patient education on the importance of urine collection; simplify the collection process with clear guidelines, flowcharts, and user-friendly containers; and provide necessary tools like graduated urinals or collection bags. Regular monitoring and feedback sessions are essential to address any issues promptly. Additionally, incentivizing participation with rewards can boost patient motivation, ensuring higher compliance and accurate urine volume measurements within the specified time frame.

A key strength of this study is its rigorous RCT design, with clear inclusion criteria, randomization, and intention-to-treat analysis, ensuring robust evidence generation. However, there are several limitations to this protocol that should be acknowledged. First, patients were recruited from a single site. This limitation may affect the generalizability of the findings, as the sample may not be representative of the broader population. Second, the current WAFIR is equipped with a fluid record function, evidence-based educational content delivery, automated reminders and notifications, and data collection and reporting. AI technologies, such as AI-driven predictive models, are not equipped within the WAFIR, as the integration could enhance its effectiveness by providing tailored health education, motivational messages, and personalized recommendations based on individual patient data and behavior patterns.

The dissemination plan includes presenting research findings at international conferences and forums and publishing in peer-reviewed journals in 2026. If proven effective, WAFIR could establish a pathway for developing other nurse-led digital interventions, offering a low-cost and scalable approach to enhance patient outcomes in chronic disease management. Furthermore, the findings will guide app developers in creating clinically validated mHealth tools and assist clinicians in integrating such interventions into standard urolithiasis care, thereby potentially transforming postoperative management practices.