Home blood pressure monitors aren’t accurate enough

Even as doctors are increasingly relying on home blood pressure monitoring to manage patients with hypertension, many of the devices are too inaccurate to be useful, according to a small study. About 70 percent of the time, home monitors weren’t accurate within 5 mmHg, which is considered clinically important, researchers say. And 30 percent of the time the devices were 10 mmHg off the mark. Hypertension, or high blood pressure, “is the number one cause of death and disability in the world,” said lead study author Jennifer Ringrose of the University of Alberta in Canada. “Guidelines are recommending that clinicians rely more on automatic and home blood pressure readings to diagnose and monitor high blood pressure,” she told Reuters Health by email. “We need to make sure these home blood pressure readings are accurate.” Ringrose and colleagues gauged the accuracy of home blood pressure monitors used by 85 patients and tested for differences between upper-arm versus wrist devices, brand names, hard versus soft cuffs and devices that were validated according to industry technical standards and those that were not. Two observers tested each patient simultaneously, taking a total of nine blood pressure measurements and alternating between the device used at home and a standardized cuff used in a doctor’s office. Blood pressure is measured with two numbers: systolic pressure when the heart pumps blood and diastolic pressure when the heart rests between beats. Blood pressure below 120 mmHg systolic/80 mmHg diastolic is considered healthy. Pressure above 140/90 mmHg is considered high. Also, older age, larger arm circumference, hard cuff design, and older device models were linked with diastolic blood pressure discrepancy. — Reuters