At-home blood pressure monitors inaccurate 70% of the time

Precision in medical devices, especially those used at home, are critical in ensuring patients are able to manage chronic conditions. In a study, published in the American Journal of Hypertension, researchers from the University of Alberta evaluated at-home blood pressure monitors for accuracy.

Researchers tested 85 patients with at-home monitors to have two observers take multiple blood pressure readings. In total, 554 devices were tested (171 upper arm and 383 wrist). These were compared to two observers taking several blood pressure measurements, with a third person ensuring agreement between both observers' readings

"High blood pressure is the number one cause of death and disability in the world," said medical researcher Jennifer Ringrose, who led the study. "Monitoring for and treating hypertension can decrease the consequences of this disease. We need to make sure that home blood pressure readings are accurate."

Results showed that while the average differences between at-home devices and the observers were acceptable, 72 percent of the devices were considered significantly inaccurate. In all, 15 percent of the devices were inaccurate within 5mmHg and 30 percent of the time were inaccurate at 10 mmHg.

“These findings indicate the need to assess and optimize the device-subject pairing, but operationalizing this objective will be difficult,” wrote Ringrose and colleagues. “Further, improving the accuracy of these commonly used, guideline-endorsed devices should be urgently prioritized. A more individualized approach to the derivation of blood pressure from the oscillometric data is needed. The lack of accuracy is not widely appreciated or understood by the clinicians recommending or the patients using these devices. Greater collaboration between industry and academia would be an important first step towards optimizing oscillometric device accuracy in individual patients.”