Adapted from Hodgkinson JA et al. Accuracy of blood pressure monitors owned by patients with hypertension (ACCU-RATE study): a cross sectional, observational study in central England. Br J Gen Pract. 2020 June 2
More and more of us are checking our own blood pressure and telling our GPs what the result is over the phone or via skype. Home monitoring has been increasing in the last ten years and has greatly accelerated with the Covid pandemic making avoiding face to face consultations a virtue.
Blood pressure checks are done to diagnose and monitor hypertension but are also a matter of routine for contraceptive pill checks, hormone replacement therapy checks, and diabetes checks.
This study was conducted on just under seven thousand general practice patients in the Midlands of England.
Those who used home blood pressure monitors had them tested against a reference monitor and those who were not within 3 mm Hg were considered to have failed. This is a pretty strict test. The cuffs were also assessed.
In all 76% of the monitors passed on the monitors and cuffs. 86% passed the monitor tests. The monitors that failed mainly tended to over estimate the blood pressure.
In general monitors that have been validated (should say so on the monitor) were more accurate than those that were not. Monitors that cost more than £10 were more accurate than those over £10. Monitors that were under four years old were more accurate than those that were older.
The authors say that BP monitors are very likely to be accurate if they have been validated and are over 4 years old.