Home blood pressure monitors may not be accurate enough

Home blood pressure monitors increasingly are being used to manage hypertension, but a new Canadian study suggests the devices are unreliable. Investigators took multiple readings from 85 participants, switching between home monitors and standardized cuffs found in doctors' offices.

Home blood pressure monitors increasingly are being used to manage hypertension, but a new Canadian study suggests the devices are unreliable. Investigators took multiple readings from 85 participants, switching between home monitors and standardized cuffs found in doctors' offices. The numbers generated by the home devices were inaccurate by 5 mmHg or more 70% of the time and off by 10 mmHg or more 30% of the time, according to the results, reported in the American Journal of Hypertension. More often than not, the researchers observed, the discrepancy was in the top number—which represents systolic pressure. Key predictors of inaccurate systolic readings included male gender and larger arm size—which, along with older device model, older age, and hard cuff vs. soft cuff—were also predictors for imprecise diastolic measurements. To obtain accurate readings, senior study author Raj Padwal of the Mazankowski Heart Institute in Alberta stresses that patients should buy a monitor that has been validated to meet industry standards and be sure to use the appropriate cuff size. Importantly, Padwal adds that researchers and device manufacturers have to develop a better machine. In the meantime, the team recommends that clinicians base diagnostic and treatment decisions on the average of multiple readings.