Sphygmomanometers in use in general practice: an overlooked aspect of quality in patient care

To assess the condition, accuracy and safety of mercury and anaeroid sphygmomanometers in use in general practice and to pilot a scheme for sphygmomanometer maintenance within the district.

Instruments were checked on site according to set protocols which related to established guidelines and standards and data were entered into a specially designed database. Mercury sphygmomanometers were removed to the laboratory for servicing. Practices received written feedback on the condition of each instrument checked, repairs undertaken and advice, where necessary, for further work required. Participant views on the scheme were sought.

A total of 472 instruments (75.4% mercury) located in 86 general practices (87.8% of practices participated) in a health district in the West Midlands. Instruments were checked against 28 (mercury) and 25 (anaeroid) quality standards and (for mercury instruments) against British Hypertension Society guidelines.

69.1% of mercury and 95.7% of anaeroid instruments checked, had no service records. Of the remainder, only 29 mercury (8.1%) and one anaeroid (0.9%) had a record of a check or service within the previous 12 months. None of the instruments met all of the relevant quality standards and 14 (3.9%) mercury and seven (6.1%) anaeroid instruments met less than half. A large proportion of mercury sphygmomanometers tested had defects likely to affect recommended measurement technique. Only two-thirds were accurate at all pressure levels tested. Only 38.8% of anaeroid instruments were accurate at all test pressure levels.

The level of defects noted could have an impact on diagnosis and monitoring of hypertension.