Evidence-based proposal for the number of ambulatory readings required for assessing blood pressure level in research settings: an analysis of the IDACO database

Abstract

, we randomly selected a certain number of readings (from 30 to 1 awake and 10 to 1 asleep readings) at a time over 1000 bootstraps at each step. We evaluated: (i) concordance of the ABP level; (ii) consistency of the cross-classification based on office blood pressure and ABP; and (iii) accuracy in predicting cardiovascular complications. For each criterion, we fitted a regression line joining data points relating outcome to the number of readings covering the ranges of 30-20/10-7 for awake/ asleep readings. Results: Reducing readings widened the SD of the systolic/diastolic differences between full (reference) and selected recordings from 1.7/1.2 (30 readings) to 14.3/10.3 mm Hg (single reading) during wakefulness, and from 1.9/1.4 to 10.3/7.7 mm Hg during sleep; lowered the j statistic from 0.94 to 0.63, and decreased the hazard ratio associated with 10/5 mm Hg increments in systolic/diastolic ABP from 1.21/1.14 to 1.06/1.04 during wakefulness and from 1.26/1.17 to 1.14/1.08 during sleep. The first data points falling off these regression lines during wakefulness/sleep corresponded to 8/3 and 8/4 readings for criteria (i) and (iii) and to 5 awake readings for criterion (ii). Conclusions: 24-h ambulatory recordings with !8/!4 awake/asleep readings yielded ABP levels similar to recordings including the guideline-recommended !20/!7 readings. These criteria save valuable data in a research setting, but are not applicable to clinical practice.

Nighttime Blood Pressure Phenotype and Cardiovascular Prognosis

“…For analysis, ambulatory recordings had to include at least 6 daytime and 3 nighttime readings. 20 Patients were classified into 4 groups based on the reduction in SBP while asleep versus awake: extreme dippers (≥20%); dippers (10%–<20%); nondippers (0%–<10%); and risers (any increase). 19 …”

Nocturnal dipping of heart rate and blood pressure in people with HIV in Tanzania

“…However, studies indicate that ABPM with as few as eight daytime readings and four nighttime readings likely still retain diagnostic and predictive accuracy. 15 In conclusion, PWH had a higher prevalence of nocturnal nondipping of BP and HR. Future research should determine the causes and consequences of nocturnal non-dipping of BP and HR in PWH to determine if non-dipping could be a novel target for intervention to prevent CVD in PWH.…”

Ambulatory blood pressure monitoring over 24 h: A Latin American Society of Hypertension position paper—accessibility, clinical use and cost effectiveness of ABPM in Latin America in year 2020

“…The evidence from the pioneering works of Di Rienzo and Thijs is still the main references supporting the frequency and timing of ABPM. Some evidence on the number of ambulatory BP readings required for reliable assessment of ambulatory BP levels was also provided by the IDACO group …”