Abstract
BACKGROUND: Hypertension is the most modifiable factor associated with cardiovascular events and complications. The conventional blood pressure (BP) meter method is simple but is limited in terms of real-time monitoring abnormal BP. Therefore, the development of a multifunction smartwatch (HUAWEI WATCH D) sphygmomanometer could significantly improve integrated BP monitoring. METHODS: We enrolled 361 subjects from Chinese PLA General Hospital, Beijing, China to validate the accuracy of the smartwatch versatile sphygmomanometer using ISO 81060-2:2018. Resting and ambulatory BP accuracy of the smartwatch were compared with gold standard clinical sphygmomanometers using ISO 81060-2:2018 guidelines, the accuracy of 24 h systolic blood pressure (SBP) circadian rhythm monitoring, and diurnal high SBP alert for this smartwatch were assessed using a confusion matrix approach. Additionally, we analyzed online users of different ages for compliance. RESULTS: Eighty-five subjects underwent resting BP measurements; the mean resting BP differences between two devices were -0.683 ± 6.203 mmHg (SBP) (P = 0.723) and 1.628 ± 5.028 mmHg (diastolic blood pressure, DBP) (P = 0.183). In 35 subjects' ambulatory BP measurements, the mean differences of ambulatory BP were -1.943 ± 5.475 mmHg (SBP) (P = 0.923) and 3.195 ± 5.862 mmHg (DBP) (P = 0.065). All data complied with ISO 81060-2:2018 guidelines (mean ≤ ±5 mmHg and standard deviation ≤ ±8 mmHg) with no significant differences. Positive predictive values (PPV) of resting SBP and DBP were 0.635 and 0.671, respectively. The PPV of ambulatory SBP and DBP were 0.686. Also, 24 h SBP circadian rhythm monitoring was performed in 107 subjects: accuracy = 0.850, specificity = 0.864, precision/PPV = 0.833, sensitivity = 0.833, and F1-measure (F1) = 0.833. The accuracy, specificity, precision, sensitivity, and F1 values in 85 subjects undergoing diurnal high SBP alerting were 0.858, 0.876, 0.706, 0.809, and 0.754, respectively. CONCLUSIONS: When compared with the gold standard clinical sphygmomanometer, smartwatch results were consistent and accurate. Online user feedback showed that elderly individuals cared more about BP monitoring accuracy, with better compliance.