Statistical Analysis
Only patients with complete data were used for the intention-to-treat analyses. In addition, patients who were discharged from the hospital the day after consent was obtained (including patients who were scheduled to be discharged before allocation) were excluded from the primary analyses. Continuous and categorical variables were expressed as median and IQR and n (%), respectively.Patients who were lent an accelerometer but who could not measure their steps after release due to early discharge from the hospital were excluded from the analysis as “early discharge.”‎ Adherence to wearing the accelerometer was defined as having enough wear records for at least 2 days and that allowed for adequate analysis. For certain patients who were lent an accelerometer for a sufficient period, if the number of days of wear record was less than 2, this was defined as “insufficient wearing data” and poor adherence and so was excluded from the primary analysis because the amount of analyzable data was not reached. Then, the adherence of both groups was compared without statistical analysis.The primary analysis was conducted after visual confirmation of the absence of abnormal distributions. Average steps were compared using analysis of covariance (ANCOVA) after adjusting for baseline age, a 4-m gait speed at the time of starting cardiac rehabilitation, the baseline step count (defined as steps taken the day after lending), the duration of wearing the accelerometer, and the duration of hospitalization. The results of the ANCOVA were expressed as an estimated value, a mean difference in the 2 groups, a 95% CI, and Cohen All analyses were performed using R (version 4.0.2; R Foundation for Statistical Computing) and JMP (version 15.1; SAS Institute Inc), and statistical significance was defined as 2-tailed 