Nocturnal blood pressureBMJ 1994; 308 doi: https://doi.org/10.1136/bmj.308.6937.1163c (Published 30 April 1994) Cite this as: BMJ 1994;308:1163
- Michael J Stewart
- Career registrar, Monklands Hospital, Airdrie ML6 OJS.
Measurement is subject to bias
EDITOR,--Though I agree with Martin Middeke and Joachim Schrader that many patients with secondary hypertension seem to have a reduced fall in nocturnal blood pressure,1 assessment of the nocturnal dip is susceptible to considerable measurement bias. Variation in the definition of day and night can have an important influence on the calculated nocturnal fall,2 and I would argue that assessment of pressures while subjects are awake and …