Extended Data Fig. 4: Details of PPG measurements.
From: Smartphone-based screening for atrial fibrillation: a pragmatic randomized clinical trial
(a-b): Plethysmographic (PPG) measurements during both phases of the trial (panel A phase 1; panel B phase 2). Solid blue line shows proportion of participants who performed ≥1 measurement per week, dotted blue line shows proportion of participants who performed ≥2 measurements per week. The percentage refers to the total number of subjects assigned to digital screening according to the modified intention-to-treat principle. The drop in PPG measurements at the end of the second study phase is due to the shorter average measurement duration in this phase, as app usage was limited to a total of 12 months and participants took a median of 10 days (IQR 22 days) to cross-over. (c-d): Number of total measurements performed by participants during the study stratified by age groups (< 59 yeas; 59 – 64 years; 65 – 71 years and > 71 years) for group 1 (c) and group 2 (d). For this analysis only active participants performing at least one PPG-measurement during the entire study duration were considered (Group 1 N = 2,484; age < 59 N = 549; age 59 – 64 N = 616; age 65 – 71 N = 787; age > 71 N = 532; Group 2 N = 2,140; age < 59 N = 452; age 59 – 64 N = 502; age 65 – 71 N = 739; age > 71 N = 447). Two-sided p-values were calculated by means of Kruskal-Wallis one-way analysis of variance; the exact p-value for (c) is 9.62 * 10−9; differences were considered statistically significant when the two-sided p-value was less than 0.05. There was no adjustment for multiple comparisons. (e-f): Number of total measurements performed by males and females during the study for group 1 (e) and group 2 (f). For this analysis only active participants performing at least one PPG-measurement during the entire study duration were considered (Group 1 N = 2,484; females N = 767; males = 1,717; Group 2 N = 2,140; females N = 658; males N = 1,482). Two-sided p-values were calculated by means of Mann-Whitney U test; the exact p-value for (e) is 1.76 * 10−5; differences were considered statistically significant when the two-sided p-value was less than 0.05. There was no adjustment for multiple comparisons. Boxplots in (c-f) show median and IQR. The whisker boundaries define the 10th and 90th percentiles.
