Participants and sample size
HD
HEART FAILURE, CHRONIC DISEASES, DISORDERS
The sample size was calculated with 95% confidence interval and 80% test power, based on the standard deviation (SD) of treatment adherence to 4.9, obtained from the previous similar study [Then, considering the 10% sample loss in each group, 35 individuals were calculated. The inclusion criteria were the patients’ willingness to​ participate in the study, aged over 18, the ability to read and write, access to a smartphone with an Android operating system, undergoing HD within the study setting permanently, experiencing three HD sessions per week, receiving HD for at least six months, using no other mHealth apps along with HD during the study, no mental illnesses or other chronic diseases, such as heart failure, and no disability causing disorders in the training process. In addition, unwillingness to continue cooperation with the study, being transferred to other centers, undergoing a kidney transplant during the study, not using the Di Care app for more than one week, not attending the face-to-face training sessions for ​over three sessions, and facing inadequate functioning of the Di Care app on smartphones were the exclusion criteria.The HD patients were recruited in this study using convenience sampling method by one of the researchers. All patients, who were in the center, enrolled in the study. Then, among those who were eager to participate, other criteria were checked to reach the calculated sample size. The study objectives were then explained to them, and informed consent was obtained. Afterward, the patients were randomized into two groups: mHealth (n = 35) and face-to-face training (n = 35) via tossing a coin, so the coin was tossed for each eligible patient and if the patients were on the coin head, they entered into the face-to-face training group, and if they were on the coin tail, they were included in the mHealth app use one. This procedure continued until the desired sample size was reached. To prevent the exchange of information between the patients in both groups, besides asking the patients not to exchange information until the end of the study, the app server was controlled daily during the intervention for the registration of patients in the face-to-face training group.