A total of 38 practices, with an average of six GPs in each, took part. In total they had over 600 devices for measuring blood pressure.
Only 13% of the devices were mercury sphygmomanometers, 32% were aneroid and 53% were digital. The remainder were hybrid devices.
Some of the sphygmomanometers were not in use and others were broken. This left 584 devices for testing.
The practices’ sphygmomanometers were tested with pressure measuring machines. Measurements were checked when the sphygmomanometers showed