To characterize different patterns of variability of three repeated within-visit blood pressure (BP) readings and to determine the prevalence of specific variation trends in systolic (SBP), diastolic (DBP) blood pressure and pulse pressure (PP).
Data from 53 737 subjects from the National Health and Nutrition Examination Survey were analyzed. In each subject, three consecutive BP measurements were performed with a minimum time-interval of at least 30 s. We propose three patterns of within-visit BP variability (separately for SBP, DBP and PP): (1) increasing trend (BP3 > BP2 > BP1); (2) decreasing trend (BP1 > BP2 > BP3) and (3) no trend (BP3 ≈ BP2 ≈ BP1). A threshold of minimum change (ΔP > 3 mmHg) between BP1-BP2 and BP2-BP3 was also applied as a prerequisite for the definition of these trends.
An increasing trend was observed among three consecutive measurements of SBP, DBP and PP in 7.4, 10.4 and 10.2%, respectively. When a minimum threshold of 3 mmHg was set the respective increasing trends were observed in 1.8, 2.9 and 4.4%, respectively. There was a higher prevalence of decreasing trend within three consecutive SBP, DBP and PP readings: 17, 13.1 and 16.2%, respectively, whereas using a threshold of ΔP >3 mmHg the respective prevalence was 6.3, 4.1 and 7.7%. A maximum absolute difference >10 mmHg within triplicate of SBP/DBP/PP readings was observed in 12.9, 13 and 29.4%, respectively. In the era of personalized medicine, these patterns are well worth further investigation concerning their pathophysiologic and clinical relevance.