User profile and engagement with a digital health application for urolithiasis management: A descriptive study of the first 699 users

Abstract

Introduction and objectives

Urolithiasis is a prevalent urological condition that requires continuous monitoring and management to prevent recurrence. The myLit-Control® App is a digital health tool designed to support self-management by tracking urinary pH, water intake, and medication adherence. This study aimed to describe the demographic and clinical characteristics of myLit-Control® App users in Spain, analyze their engagement patterns, and evaluate adherence to health goals.

Patients and methods

This retrospective observational study included users who downloaded the app between May 2022 and June 2024. Data on demographics, urinary pH tracking, water intake, and medication adherence were extracted and analyzed to explore correlations, group comparisons, and identify factors influencing adherence and outcomes.

Results

The study included 699 users, with a median age of 50 years (IQR 40–59) and 57.1% male. A total of 217 users (31.0%) were taking urolithiasis-specific treatment. Urine pH monitoring was used by 52.9% of participants, with a rate of 53% (± 37) within target pH levels. Water intake tracking was the most frequently used feature, yet adherence to hydration goals remained low (15 ± 30%). A negative correlation was observed between age and treatment adherence (r = −0.456, p < 0.001).

Conclusions

The myLit-Control® App facilitates urinary pH monitoring and medication adherence, supporting self-management in urolithiasis patients. However, engagement with key features, particularly water intake tracking, remains suboptimal. Future research should explore long-term outcomes and strategies to enhance patient adherence, ensuring effective integration of mHealth tools in routine clinical practice.

Resumen

Introducción y objetivos

La urolitiasis es una patología urológica prevalente que requiere monitorización y manejo continuos para prevenir la recurrencia. La aplicación myLit-Control® es una herramienta digital de salud diseñada para facilitar el autocontrol, permitiendo el registro del pH urinario, la ingesta de agua y la adherencia al tratamiento farmacológico. Este estudio tuvo como objetivo describir las características demográficas y clínicas de los usuarios de la aplicación myLit-Control® en España, analizar sus patrones de uso y grado de implicación, y evaluar el cumplimiento de los objetivos de salud.

Pacientes y métodos

Estudio observacional retrospectivo que incluyó usuarios que descargaron la aplicación entre mayo de 2022 y junio de 2024. Se recopilaron y analizaron datos demográficos, registros del pH urinario, la ingesta de agua y adherencia al tratamiento, con el fin de explorar correlaciones, realizar comparaciones entre grupos e identificar factores asociados a la adherencia y los resultados clínicos.

Resultados

Se incluyeron 699 usuarios, con una edad mediana de 50 años (RIQ 40–59) y un 57,1% de varones. Un total de 217 usuarios (31,0%) estaba en tratamiento específico para urolitiasis. El 52.9% de los participantes utilizaba la monitorización del pH urinario, pero solo el 53% (± 37) de las mediciones estaban dentro del rango objetivo de pH. La monitorización de la ingesta de agua fue la funcionalidad más utilizada, aunque el cumplimiento de las metas de hidratación fue bajo (15 ± 30%). Se observó una correlación negativa entre la edad y la adherencia al tratamiento (r = -0,456; p < 0,001).

Conclusiones

La aplicación myLit-Control® facilita la monitorización del pH urinario y de la adherencia farmacológica, promoviendo el autocuidado en pacientes con urolitiasis. Sin embargo, la implicación de los usuarios con las funcionalidades principales, como la monitorización de la hidratación, continúa siendo mejorable. Futuras investigaciones deberán evaluar los resultados a largo plazo y desarrollar estrategias que mejoren la adherencia del paciente, para asegurar la integración eficaz de herramientas de salud digital en la práctica clínica habitual.

Introduction

Urolithiasis, or kidney stone disease, is a prevalent urological disorder characterized by calculi formation within the urinary tract. The pathophysiology of urolithiasis is multifaceted and involves the supersaturation of urine with stone-forming constituents such as calcium, oxalate, and uric acid, leading to crystal nucleation, growth, and aggregation.¹ Patients often experience acute pain, recurrent urinary tract infections, and complications such as obstructive uropathy and chronic kidney disease. The economic impact is considerable, encompassing both direct costs related to healthcare and indirect costs due to loss of productivity.²

Urinary pH plays a pivotal role in the development of urolithiasis as it influences the solubility of various stone-forming salts. For instance, a higher urine pH (typically > 6.2) can diminish the solubility of calcium phosphate, promoting stone formation, whereas a lower pH (typically < 5.5) increases the risk of uric acid stone development. Traditionally, urinary pH measurements have been conducted using reagent dipsticks, which are widely available and relatively easy to use. However, their limitations include reduced accuracy and sensitivity, and reliance on subjective interpretation of color changes.³ Alternatively, portable electronic pH meters provide greater accuracy and reproducibility than dipsticks, making them particularly valuable for individuals requiring tight control of urinary pH as part of their stone prevention strategy.^4,5 As such, the smart Lit-Control® pH Meter 2.0 integrates with a mobile health application, the myLit-Control® App, enabling real-time tracking and analysis of pH levels, and has been demonstrated to be useful for urolithiasis patients for urine pH monitoring at home.⁶ The integration of mobile health (mHealth) solutions, such as the myLit-Control® app, is justified by the need for sustained lifestyle modifications, treatment adherence, and continuous monitoring—factors known to reduce stone recurrence but often difficult to maintain over time.⁷

In this context, understanding user engagement with such digital health applications is crucial. Thus, this study aimed to provide a comprehensive description of the demographic and clinical characteristics of users of the myLit-Control® App in Spain, as well as their engagement patterns, compliance with health management goals, and adherence to treatment. By analyzing user behavior and correlations between variables, this research sought to identify factors influencing app utilization and health outcomes in a real-world population engaged in the self-management of urolithiasis.

Patients and methods

General overview of the App

The myLit-Control® App is an mHealth tool intended to support self-management of urolithiasis patients developed by Devicare S.L.⁶ In Spain, the app has been available since May 2022, and 910 users have installed it by December 2024. The app provides information materials and tools to monitor urinary pH, water intake, and medication adherence and allows users to synchronize data from the smart Lit-Control® pH Meter 2.0 by a bluetooth connection.⁸ Users can view historical data and trend graphs, set clinical goals, and reminders for testing their pH, taking medication, drinking water, and accessing lifestyle recommendations (Fig. 1). In addition, the app allows data sharing between the patient and the clinician.

Figure 1.

Screenshots from the myLit-Control App showing the main features: device status (A), learning tools (B), pH readings (C), and statistics/compliance (D).

Participants

Participants were individuals who downloaded the myLit-Control® App between May 1, 2022, and June 30, 2024, the cut-off time of the current analysis. The participants were primarily recruited from urological outpatient facilities, where the treating physicians recommended monitoring their urinary pH, water intake and/or medication due to the risk of kidney stone formation or recurrence. Prior to using the app, individuals were asked to provide their consent to share aggregated, de-identified data for research purposes and were subsequently prompted to fill out their demographic and clinical information and complete the app’s onboarding settings. As part of their routine clinical management, some patients were prescribed a specific treatment according to their urolithiasis characteristics: Lit-Control® pH Up (which alkalinizes urine and is intended for the treatment and prevention of uric acid stones), Lit-Control® pH Down (which acidifies urine and is intended for the prevention of infection-related stones), or Lit-Control® pH Balance (intended for the prevention of calcium-based stones).

Outcomes

Demographic information including age, sex, and body measurements (height, weight, and body mass index [BMI]) were collected. Additional data on user engagement with app features were analyzed according to the following variables:

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  Urine pH monitoring, including frequency and compliance with preventive ranges.

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  Average water intake (daily and in relation to goals).

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  Type of treatment and adherence metrics, such as the average daily dose and compliance rates.

Data analysis

Extraction, compilation, and descriptive analysis of the data were performed using SPSS software version 27.0, and user characteristics were measured as median, interquartile range (IQR), and range for continuous variables, and frequency and proportion for categorical variables. Summary statistics were used to report user engagement (mean, SD, median, IQR, frequency, and proportion) among the entire sample and by type of Lit-Control® treatment. The Pearson correlation coefficient was used to assess correlations between variables. When comparing more than two categories, analysis of variance (ANOVA) or the Kruskal-Wallis test was used, as appropriate. The significance level was set at a p-value of .05.

Results

Demographic and clinical characteristics of users

This analysis included 699 users of the myLit-Control® App, of which 399 (57.1%) were male and 300 (42.9%) were female. The median age of the users was 50 (IQR 40–59; range, 19–86) years, and their median BMI was 25 (IQR 22–27) kg/m². A total of 217 (31.0%) users were taking any of the three Lit-Control® treatments, the most frequent being the pH-Balance (see Table 1). The most common posology prescribed was 1-0-1 (44.9%), followed by 0-0-1 (16.5%), 1-0-0 (13.2%), 0-1-0 (4.3%). The most common duration of treatment prescribed was chronic use (57.4%), followed by 3 mo (18.2%) and 6 mo (16.8%). The pH-Down product was more common among women (67.4% vs. 32.6%), whereas the pH-Up and pH-Balance products were more common among men (63.0% vs. 37.0% and 60.2% vs. 39.8%, respectively).

Table 1.

Overall sample demographic and clinical characteristics.

Variable	Total users (N = 699)
Sex, females, n (%)	300 (42.9)
Age (years), median (IQR)	50 (40–59)
Body weight (Kg), median (IQR)	75 (64–85)
BMI (Kg/m^2), median (IQR)	25 (23–28)
Type of treatment, n (%)	(n = 217)
Lit-Control® pH Up	73 (33.6)
Lit-Control® pH Down	46 (21.2)
Lit-Control® pH Balance	98 (45.2)

BMI, Body mass index; IQR, interquartile range.

Patterns of App usage and goal compliance rates

The analysis of app functionalities revealed good user engagement with key features (Fig. 2), and 75% of participants used at least one monitoring tool. Water intake tracking was the most frequently used functionality, with 66.2% of users recording their consumption during a median of 488 days (IQR, 178–621) since their initial recording. Compliance with daily water intake goals was low, averaging 15.2% (SD ± 29.5), with a median recorded intake of only 840 mL (IQR, 400–1452) (Table 2). Urine pH monitoring was used by 52.9% of users, who tracked this parameter for a median of 468 days (IQR, 186–613). Compliance with the target urine pH range goals was fair at 52.9% (SD ± 36.8) with a mean daily urine pH of 6.1 (SD ± 0.6). All 217 patients who were taking the Lit-Control® treatments completed the setup configuration for treatment adherence tracking and used it during a median of 152 days (IQR, 81–545). Compliance with treatment goals was relatively high at 58.3% (SD ± 41.7), with an average daily dose of 1.5 doses (SD ± 0.6). Table 2 shows the goal set for each feature and the respective real values recorded by the users.

Figure 2.

App functionalities used by the participants.

Table 2.

Goals and recorded values for each feature.

Feature	Goals set up by the users (median, IQR)	Real value (median, IQR or mean ± SD)	Compliance with the goal (mean ± SD)
Water intake tracking	2000, IQR 2000–2700 mL	840, IQR 400–1452 mL	15% ± 29
Urine pH monitoring	Most common target range: 5.50–6.20 (86% of users)	6.1 ± 0.6	53% ± 37
Treatment adherence	1 or 2 pills/day (87% of users)	1.5 ± 0.6 pills	58% ± 42

SD, standard deviation.

Differences between treatment groups

When patients were compared according to their type of treatment, we observed that those receiving the Lit-Control® pH Up had higher body weight (median [IQR], 80 [66–88] Kg) than those treated with the pH-Down product (74, 6381 Kg) or the pH-Balance product (75, 62–84 Kg) (p = 0.016). Interestingly, users of the Lit-Control® pH Balance demonstrated significantly higher performance in several compliance and usage metrics: they recorded a higher median daily water intake than pH-Down users (1406 mL vs. 675 mL; p = 0.006) and achieved a higher percentage of days meeting their water intake goals (22.7% vs. 6.3%; p = 0.033). Regarding treatment adherence, pH-Balance users achieved a higher number of days meeting their daily dosage goals (60.6 ± 121.6 days) compared to both pH-Up (5.1 ± 6.9 days) and pH-Down groups (5.0 ± 6.7 days) (p = 0.005). They also surpassed the other groups in the percentage of days meeting their daily pill intake goals (71.7% vs. 48.9% and 48.4%; p = 0.030).

Associations between user characteristics and tracked variables

We found a correlation coefficient between age and average urine pH of −0.441 (p < 0.001), indicating a moderate negative relationship. The scatterplot shows a gradual decline in pH values with advancing age, although the spread of points indicates variability among individuals (Fig. 3A). There was also a moderate negative correlation between age and goal adherence for treatment intake, with adherence decreasing as age increased (r = −0.456; p < 0.001). This indicates that older users tend to have lower adherence rates to treatment goals than younger users, although there was considerable variability (Fig. 3B).

Figure 3.

Correlations between age and tracked variables (A: Urine pH; B: Treatment goal compliance).

Discussion

This study provides a comprehensive analysis of the demographic and clinical characteristics of myLit-Control® App users in Spain, their engagement patterns, and compliance with health-management goals. The participants in this study likely faced an elevated risk of urolithiasis, which would probably be the main reason for their use of the myLit-Control® App. This inference was supported by several key characteristics observed in the user population. Firstly, the median age of the users was 50 years. Epidemiological data indicate that the prevalence of urolithiasis is notably higher in middle-aged individuals. For instance, a study focusing on the Spanish population reported a higher prevalence of urolithiasis in individuals aged 46–50 and 61–65 years.⁹ This age-related trend is attributed to the cumulative exposure to risk factors and age-associated physiological changes (pH acidification) that predispose individuals to stone formation.¹⁰ Second, a median BMI of 25.0 kg/m² places the average user in the overweight category. Being overweight and obese are well-established risk factors for urolithiasis.¹¹ A meta-analysis involving over 13,000 patients demonstrated a strong association between higher BMI and the formation of uric acid and calcium oxalate stones.¹² The gender distribution within the app’s user base revealed a higher proportion of male users (57.1%). This aligns with global epidemiological patterns, where males exhibit a higher incidence of urolithiasis compared to females.¹³

Lit-Control® Balance was the most frequently used treatment among app users, accounting for 45.2% of the treatments recorded. This is probably because Lit-Control® Balance is intended for the prevention of calcium-based kidney stones which account approximately 80% of all urinary calculi.¹⁴ Thus, the use of this type of therapy represents a versatile strategy for a wide range of patients or when multiple stone compositions are suspected.¹⁵ However, we also found gender-specific differences in the prescribed treatments, with Lit-Control® pH Down being more frequently used by women, while the pH-Balance, and specially the pH-Up, products were more common among men. This distribution may reflect differences in the types of stones prevalent in each gender.¹⁶ Women are more prone to infection-related struvite stones, which are formed in alkaline urine, potentially driving the doctor’s recommendation of using Lit-Control® pH Down to acidify the urine. In contrast, men may be more susceptible to uric acid stones, conditions that align with the use of the pH Up product that alkalinizes the urine and inhibits uric acid crystallization by its components, citrate and theobromine, respectively.^17,18

eHealth technologies are increasingly being used to improve lifestyle behaviors and manage chronic illnesses with varying degrees of success.^19,20 Among patients with urolithiasis, the risk of recurrence can be modified in part by behavioral interventions, primarily by increasing fluid consumption and adherence to preventive treatments that modify the urinary pH and provide inhibitors of crystallization. In this study, user engagement with the app was substantial, with 75% utilizing at least one monitoring tool, indicating the feasibility and acceptability of digital health solutions in this population.⁶ Compliance with health goals varied among the participants. Water intake tracking was the most utilized feature; however, compliance with daily water intake goals was low (15.2%). This is consistent with the findings that maintaining long-term behavioral changes, such as increasing fluid intake, is difficult for many patients,⁷ even with the aid of technology.²¹ Urine pH monitoring showed better compliance, with 52.9% of the users achieving the target pH range. Regular monitoring and maintenance of urinary pH are vital in preventing stone recurrence, and the app’s facilitation of this practice is encouraging. Treatment tracking was utilized by all users, with a goal compliance rate of 58.3%, highlighting the app’s potential to promote adherence to therapeutic regimens. Accordingly, the systematic review by Ungerer et al. highlighted that mobile health technologies have the potential to enhance chronic disease management, including kidney stone disease, by facilitating behavioral changes.​²²

Notably, users of the Lit-Control® pH Balance product demonstrated superior performance across several metrics compared with the pH-Up and pH-Down groups. These users had a higher average daily water intake and greater adherence to treatment dosage goals, which could reflect a more proactive approach to stone prevention. Patients using pH-Up or pH-Down products may focus primarily on pH correction rather than hydration, whereas pH Balance users may rely more on hydration as a preventive strategy. Better adherence could be attributed to user preferences or the perceived efficacy of the product. On the other hand, the observed negative correlation between age and treatment adherence (r = −0.456, p < 0.001) may not solely reflect lower adherence among older users, but could also indicate a tendency for elderly individuals not recording it in the app. Nevertheless, it is important to highlight that 25% of the users of myLit Control® app were 60 years or older, with a maximum age of 86 years. Moreover, older patients usually receive multiple medications and may particularly benefit from structured adherence support offered by the app.²³ Health providers play a critical role in encouraging the use of health apps like myLit-Control®. By recommending, educating, and integrating app data into clinical care, they can significantly improve adherence, engagement, and health outcomes in patients managing urolithiasis.²⁴ As digital health continues to evolve, physician-led promotion will be key to optimizing patient care.

This study has several limitations. First, it relies on self-reported data that may be subject to reporting bias. Second, the use of Lit-Control® treatments (pH Up, pH Down, and pH Balance), which are commercial products from the same brand as the app, may have influenced users’ motivation to engage with the application. Although only 31% of users in our cohort were actively taking one of these products, this potential brand-treatment interaction should be considered when interpreting the applicability of our findings to broader populations. Third, the cross-sectional design prevented us from drawing causal inferences about the relationships between user characteristics and compliance metrics. We had no access to participants’ clinical histories, including information on other medical conditions that may influence treatment adherence. This would help to identify subgroups that may benefit from targeted interventions or additional support to improve engagement and adherence.²⁵ Finally, the study did not account for external factors, such as dietary habits, physical activity, or socioeconomic status, which may influence urolithiasis self-management and outcomes.

Conclusion

The use of the myLit-Control® App empowers kidney stone patients to manage their disease effectively. Incorporating specific medications for each type of stone and pH-monitoring, together with water intake tracking systems, into a comprehensive management plan for urolithiasis could not only prevent stone recurrence but also improve patients’ quality of life and reduce the associated healthcare costs. Our findings offer valuable insights into user behaviors and outcomes, which are essential for optimizing digital tools for urolithiasis management. Future studies should assess the long-term impact of the myLit-Control® App in routine clinical practice and evaluate whether (current and future) app users achieve better adherence, maintain target pH levels more effectively, and experience improved clinical outcomes. Additionally, these findings serve as a foundation for future prospective, controlled studies that can evaluate the app’s effectiveness in improving treatment adherence and reducing the risk of urolithiasis recurrence.

CRediT authorship contribution statement

All the authors contributed to the conception and design of the study. Coordination was performed by B Isern-Amengual. Data analysis was performed by P Sanchís-Cortés. The first draft of the manuscript was written by B Isern-Amengual; review and editing were carried out by JA Mainez, JA Galán, JM López, and P Sanchís-Cortés. All authors have read and approved the final manuscript.

Ethics approval and consent to participate

All participants provided consent to use the data for research purposes.

Funding

The sponsor of this study was Devicare S.L. The sponsor funded the medical writing assistance.

Acknowledgments

The authors thank Anabel Herrero, PhD. for providing medical writing and editing support.