Participants and recruitment
heart failure, cognitive disorders
HEART FAILURE
Participants were recruited from cardiovascular outpatient clinics at two large tertiary medical centers in Korea. One hundred patients were screened for eligibility with the following criteria. Patients were eligible to participate if they were: (1) diagnosed with heart failure by a cardiologist and regularly visiting the hospital clinic for medical follow-ups; (2) between 20–79 years of age; (3) able to use a smartphone app; (4) able to perform regular physical activity according to the patients’ self-identification and the judgment of their primary cardiologist; and (5) willing to participate in the study. Patients suffering from cognitive disorders or participating in another clinical trial were excluded from participation.We calculated the sample size adequacy using G*Power 3.1 software [