Variation of within visit blood pressure readings at a single visit in the elderly and their relationship to ambulatory measurements.

The value of routinely taking one or several BP readings at a single visit in subjects with an initially elevated BP reading is unclear. The variation of sequential BP readings in the elderly, who often have a disproportionate increase in SBP compared with DBP, has received little attention. In addition, no attempt has been made to relate the various BP readings obtained to a subject's ambulatory daytime BP. The aim of this study was to examine the variation in BP between one, two or three readings at a single visit in elderly subjects with elevated BPs and to compare these readings with those obtained from daytime ambulatory BP monitoring (ABPM). Sixty-nine subjects, mean age 76 years (range 66-86 years) with at least one SBP reading > 150 mmHg and who had undergone a minimum of two previous clinic visits for BP measurement by the same physician were included. Following five minutes rest three supine BP readings were taken, spaced two minutes apart, using a Hawksley random zero sphygmomanometer. Seventeen subjects underwent home 24h ABPM commencing immediately after the clinic BP readings. Clinic SBP fell from first to third reading by 11 mmHg (95% Cl 9-13 mmHg, P < 0.001) and from first to second readings by 6 mmHg (Cl 4-8 mmHg, P < 0.01). There was no change in mean DBP between readings. In 85% of readings first SBPs were higher than the second.(ABSTRACT TRUNCATED AT 250 WORDS)