Smartphone Ownership Among Cardiology Inpatients Pre–COVID-19 and Post–COVID-19 Pandemic: Secondary Analysis of Randomized Controlled Trials

Background: Mobile health (mHealth) interventions are increasing in popularity for the management of heart failure and coronary artery disease. The use of these interventions is dependent on rates of smartphone ownership. It is estimated that approximately 90% of the Australian adult population owns a smartphone; however, international studies suggest that smartphone ownership is significantly lower in patient populations, ranging from 34% to 91%. Smartphone ownership in patients with cardiovascular disease has not previously been examined. Objective: This study aimed to examine and compare pre-COVID-19 and post-COVID-19 pandemic smartphone ownership rates of inpatients admitted with coronary artery disease or heart failure. Methods: Data from prescreening logs of 2 multicenter randomized controlled trials, TeleClinical Care (TCC)-Pilot and TCC-Cardiac, were reviewed. TCC-Pilot recruited patients between February 2019 and March 2020. This formed the pre-COVID-19 cohort, with 377 patients screened who lived in Sydney, had a qualifying hospital admission, and had information regarding their phone ownership status. TCC-Cardiac recruited patients from July 2021 to February 2023, with 718 patients meeting the criteria and forming the post-COVID-19 cohort. Supplemental patient demographic and medical history data were collected from the electronic medical record. Results: In the pre-COVID-19 cohort (N=377), 194 (51.5%) patients owned smartphones, 79 (21%) owned phones that were incompatible with the mHealth intervention, and the remaining 104 (27.6%) did not own a mobile phone. Smartphone owners were predominantly male (P