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Accuracy of blood pressure monitors used for BP checks in retail pharmacies



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Hodgkinson, James 
Koshiaris, Consantinos 
Martin, Una 
Heneghan, Carl 


BACKGROUND: Free blood pressure (BP) checks offered by community pharmacies offer a potentially useful opportunity to diagnose and/or manage hypertension, but the accuracy of the sphygmomanometers in use is currently unknown.

AIM: To assess the accuracy of validated automatic BP monitors used for BP checks in a UK retail pharmacy chain. Design and Setting 52 pharmacies from one chain were visited in a range of locations (inner city, suburban, rural) in central England.

METHOD: Monitor accuracy was compared to a calibrated reference device (Omron PA-350), at 50 mmHg intervals across the range 0-300 mmHg (static pressure test), with a difference from the reference monitor of +/-3 mmHg at any interval considered a failure. The results were analysed by usage rates and length of time in service.

RESULTS: Eight (13%) monitors failed (i.e. were more than 3mmHg from reference), all underestimating BP. Monitor failure rate from the reference monitor of +/- 3 mmHg at any testing interval varied by length of time in use (2/38, 5% before 18 months vs. 4/14, 29% after 18 months; p=0.038) and to some extent but non-significantly by usage rates (4/22, 18% in monitors used more than once daily vs. 2/33, 6% in those used less frequently; p=0.204).

CONCLUSION: BP monitors within a pharmacy setting fail at similar rates to those in general practice. Annual calibration checks for blood pressure monitors are needed, even for new monitors, since these data indicate declining performance from 18 months onwards.



primary health care, hypertension, blood pressure monitors, calibration, community pharmacy services

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The British Journal of General Practice

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The British Journal of General Practice

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This work represents independent research commissioned by the National Institute for Health Research (NIHR) under its Programme Grants for Applied Research funding scheme (RP-PG-0407–10347). The views expressed in this study are those of the authors and not necessarily of the NHS, the NIHR or the Department of Health. RJM is supported by an NIHR Professorship (NIHR-RP-02-12-015) and by the NIHR Collaboration for Leadership in Applied Health Research and Care (CLAHRC) Oxford at Oxford Health NHS Foundation Trust. FDRH is part funded as Director of the National Institute for Health Research (NIHR) School for Primary Care Research (SPCR), Theme Leader of the NIHR Oxford Biomedical Research Centre (BRC), and Director of the NIHR CLAHRC Oxford.