The use of automated blood pressure monitors is recommended by current guidelines; however, the accuracy of the device must be validated according to standardized protocols. Wrist blood pressure monitors have been undergoing technical improvements; nonetheless, their reliability is not unanimously recognized. No systematic review to date has analyzed the accuracy of wrist blood pressure monitors according to standardized protocols. This study aims to summarize the evidence on the accuracy of wrist blood pressure monitors in adults.

Three databases (PubMed, Scopus and SciELO) were searched on 9 September 2019. The PICO (Patient, Intervention, Comparison and Outcome) strategy was used to outline the research question: Do automated wrist blood pressure monitors have accuracy equivalent to mercury sphygmomanometers in adults? Validation studies of wrist blood pressure monitors were included. Two reviewers independently screened abstracts and full texts. Summary data was extracted for each device, including mean difference of systolic blood pressure (SBP) and diastolic blood pressure (DBP) between the monitor and the mercury sphygmomanometer.

The review identified twenty-nine validation studies. Most of them were developed in China (44.82%), followed by Italy (20.68%). The most commonly used validation protocol was from the British Society of Hypertension. The mean difference between the devices and the mercury sphygmomanometers was 0.47 (±5.75) mmHg for SBP and 0.17 (±4.75) mmHg for DBP. The percentage of wrist blood pressure monitors that passed validation protocols was 93.1.

Most automated wrist blood pressure monitors showed accuracy equivalent to the reference standard for blood pressure measurement, with mean differences less than 0.5 mmHg for SBP and 0.2 for DBP. This evidence supports the recommendation to adopt this technology for the measurement of blood pressure in adults. However, wrist blood pressure monitors have patient positioning specificities, which, if not followed, may lead to measurement errors. Therefore, the adoption of these monitors should consider not only their accuracy, but also aspects of patient use and preferences.