Dear John,

I'm your man, having been on the British Hypertension Society working party on validating automated and semi-automated sphygmomanometers.

If you take two successive readings in a short time, the second tends to be lower than the first. The SD of repeated readings, both systolic and diastolic, is at least 8 mm Hg. The BHS recommendation is always to take at least two measurements and average them, because of the measurement error.

Automated meters occasionally produce spurious unusually high readings. For this reason, Altman and I had to develop a non-parametric approach to estimating agreement. I would definitely want to repeat the series before acting. However, if I got three successive home measurements above 140 mm Hg twice running, I would get medical advice.

I took my Omron to the GP with me and we did simultaneous measurements on different arms to check mine against hers. They agreed.

Martin

On 6 June 2017 at 10:01, John Bibby <[log in to unmask]> wrote:

Blood pressure: I just took my readings three times in 3 minutes. I got 210, 170, 140. Does anybody know anything about the error structure of blood pressure monitor readings?

JOHN BIBBY
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