Smartphone and application use in self-management of chronic kidney disease: a cross-sectional feasibility study

ABSTRACT INTRODUCTION: Smartphone and application use can improve communication and monitoring of chronic diseases, including chronic kidney disease, through self-management and increased adherence to treatment. OBJECTIVE: To assess smartphone use in patients with chronic kidney disease on dialysis and their willingness to use mobile applications as a disease self-management strategy. DESIGN AND SETTING: This was a cross-sectional study of chronic kidney disease patients on hemodialysis in the São Francisco Valley in the Northeast Region, Brazil. METHODS: The questionnaire developed by the authors was administered between April and June 2021. Cronbach's alpha coefficient for the construct was 0.69. Associations between the dependent and independent variables were determined using univariate analysis. Multivariate analysis with logistic regression analysis was also performed. RESULTS: A total of 381 patients were included, of whom 64% had a smartphone, although only 3.1% knew of a kidney disease-related application. However, 59.3% believed that using an application could help them manage their disease. Having a smartphone was associated with treatment adherence, higher educational attainment, and higher per capita income. Educational attainment remained an independent factor in multivariate analysis. CONCLUSION: More than 64% of patients had a smartphone, although few knew of applications developed for kidney disease. More than half of the population believed that technology use could benefit chronic kidney disease treatment. Smartphone ownership was more common among the younger population, with higher educational attainment and income, and was associated with greater adherence to hemodialysis sessions.


INTRODUCTION
Chronic kidney disease (CKD) is a worldwide public health problem, with approximately 10% of the world population having some degree of CKD. It has significant social and financial implications for both developed and developing countries. [1][2][3] International estimates further indicate that the number of people who need renal replacement therapy (RRT) will increase from 2,618 million in 2010 to 5,439 million by 2030. 4 However, not everyone who needs RRT can access the treatment, because it is not universally covered worldwide. 5 In Brazil, RRT is universally covered by the Unified Health System. According to the Brazilian Society of Nephrology, the estimated number of new patients undergoing dialysis in 2019 was 45,852 -a 7.7% increase from 2018, along with a 3.9% mean increase in CKD prevalence in the same period. 6 Adherence to treatment poses an immense challenge for patients with CKD, their relatives, and health teams. The importance of individualized care has been emphasized, including realistic patient-centered goals and shared decision-making between the health team and patient. For this strategy to be effective, the patient's cognitive function, health knowledge, socioeconomic factors, and treatment experiences must be considered. 7,8 Hence, a viable alternative is to align therapeutic strategies with effervescent technological growth and include this as a tool to achieve better health outcomes via mobile health (mHealth).
According to the International Telecommunication Union, 66.6% of the world's population were using mobile Internet at the beginning of 2021. The number of smartphones in use has increased by 7% per year, with an average of more than one million new smartphones coming into use every day. Even though health technology is used in high-income countries, the widespread use and accessibility of mobile phones have enabled its proliferation in low-and medium-income countries, thereby reaching more people in limited-resource settings. 10 Recent studies show that mobile devices have improved regular communication and monitoring between health professionals and their patients, as well as adherence to medication use and lifestyle changes. [11][12][13] The coronavirus disease 2019 (COVID-19) pandemic has caused rapid unprecedented growth in the use of technology in the health field. However, barriers and challenges-such as patients' lack of knowledge and Internet connectivity, health professionals' limited competence in mHealth, and financial challenges-can hinder the adoption of such interventions. 14 Thus, to obtain optimal results with this tool, it is important to know the target population of the technology, understand the current limitations, and assess the individuals' knowledge of this resource and willingness to use it.

OBJECTIVE
The objective of this study was to assess the use of smartphones by CKD patients on dialysis and their willingness to use mobile applications as a strategy for disease self-management.

METHODS
This was an analytical cross-sectional quantitative study of CKD Participants then signed an informed consent form agreeing to their voluntary participation in the research.

RESULTS
The patients' ages ranged from 19 to 92 years, with a mean age (± SD) of 50.8 (± 16.0) years. Most participants were male (n = 240; 63.0%), had completed middle school (n = 129; 33.3%), and earned an income ranging from one to two times the minimum wage (n = 286; 75.1%). The minimum wage at the time was R$ 1,100.00 (US$ 202.00). The sample characteristics are listed in Table 1.
However, approximately 60% of the patients considered that using a mobile application could help manage kidney disease.
Having a smartphone was associated with adherence to treatment, higher educational attainment, and higher per capita income ( Table 3). The mean age of the patients who had a smartphone (44.7 ± 13.5 years) was statistically lower (P < 0.001) than that of the patients who did not have one (61.7 ±

years).
Moreover, according to the OR calculated for the association of baseline characteristics with mobile phone use, only educational attainment remained an independent factor in smartphone acquisition ( Table 4). In addition, the other clinical variables analyzed were not related to mobile phone use nor to kidney disease-related mobile applications.

DISCUSSION
Few studies have assessed the use of innovative technologies, including smartphones and applications, as auxiliary methods for treating CKD patients to increase their treatment adherence. Low adherence to CKD treatment has been associated with a greater probability of disease progression and higher mortality. 15 The study participants were predominantly male, multiracial, married, catholic, with low educational attainment and low income. This reflects the epidemiological profile of the Brazilian population on dialysis. Approximately 65% of the studied patients had a smartphone, and more than half of them used applications in their daily routine. The most used applications were social media, such as WhatsApp, Facebook, and Instagram.
Few participants knew of an application to help with kidney treatment. However, more than half of the participants still considered it important and believed it could help them to manage their health conditions. Moreover, smartphone use was associated with income, educational attainment, and adherence to hemodialysis treatment.
A global study investigated CKD epidemiology in 2017 and found a higher prevalence of women in the initial stages of CKD, whereas there were more men in the final stages; moreover, the mortality rates were higher among men. 16    has become accessible and desired by a larger significant portion of the population. 22 A study of 949 patients on dialysis in the United States showed that 81% of them had smartphones, 72% reported using the Internet, and 60% were interested in using mHealth to manage their health. 23 Another study conducted on patients on dialysis in Australia found that 83.5% of them had mobile phones, although only 36.6% used applications. 24 In the present study, this percentage was smaller, which points to the lower purchasing power of patients on dialysis in Brazil. Nevertheless, despite not knowing about any CKD applications, the patients believed that CKD applications could be effective.
One barrier to the implementation of this technology is the limited knowledge of the potential benefits of CKD applications for both users and health professionals. While health professionals recognize the potential of CKD applications, they lack the knowledge, time, and skill to search, assess, and recommend reliable applications, thus highlighting that these technologies need support policies and better publicization. 25 Health teams must be trained to both use and encourage the use of applications, as they are agents who promote health education, and whom patients trust. 10 There are Portuguese applications aimed at CKD patients; for example, Renal Health, which has multiple tools such as a smart medication box with reminder alarms, monthly examination charts, liquid and diet control, and general information on kidney disease. 26 Age, marital status, educational attainment, and income were associated with smartphone use. Younger, single people with higher educational attainment and income tend to have smartphones, in contrast to older, married individuals with lower educational attainment and income. These results corroborate those of other studies in which age, educational attainment, and income were factors associated with smartphone use. 23,27,28 A primary objective of introducing mobile phone use to promote health self-management is to increase treatment adherence.
Patients with CKD must adhere to four treatment pillars: hemodialysis, restricted fluid intake, diet, and medication use. Regarding hemodialysis, only 18.9% of the participants in this study were non-adherent to therapy. Smartphone use was associated with treatment adherence. Thus, it can be inferred that mobile phone use is an interesting tool for increasing adherence. Despite not using specific CKD applications, participants belonged to instant message groups that exchanged information on the disease, its treatment, difficulties, and challenges (data not shown). These platforms allow them to share their afflictions and experiences, generating empathy and consequently energy to continue the treatment. 29 A systematic review demonstrated that 70% of the studies reported statistical associations between social support and adherence to treatment; moreover, other studies identified social and family support as protective factors against non-adherence to treatment. 30 Generally, adhering to a given treatment is similar to acquiring a new habit in which information is obtained and incorporated into the routine. However, understanding the person's perceptions and difficulties and becoming acquainted and establishing ties with them simplifies this process. 31 The to efficiently implementing such resources in the country. A limitation of this study is the single-period and single-service data collection. Thus, although the associations between the variables were assessed, causality between them was not.

CONCLUSION
More than 64% of CKD patients on dialysis treatment had a smartphone, and 54.9% used applications. Although few patients knew of applications aimed at kidney disease, more than half of them believed that such technology use may benefit CKD treatment. Having a smartphone was more frequent among younger patients with higher educational attainment and income and was also associated with greater adherence to hemodialysis sessions.