High-frequency, short-duration home BP monitoring protocol yields time, cost savings
Taking 10 resting blood pressure (BP) readings daily for 2 days provides a reliable, stable representation of patients’ resting systolic (S)BP and diastolic (D)BP, according to a study. This approach shows that the current home BP monitoring protocol of twice-daily readings for 4–7 days may be trimmed down to just 48 hours.
“This 2-day method would offer meaningful time saving for patients, and financial and time benefits for doctors and their surgery administration. The oscillometric home monitors lent to patients by practices can be used for more patient management episodes, compared against 4-day to 7-day protocols,” the investigators said.
In the study, 1,045 individuals (mean age 66 years; 50.8 percent female) completed 20 resting SBP and DBP measurements consistent with the Stowhealth home BP monitoring procedure. All readings were taken using automated oscillometric monitors.
For the entire cohort, mean resting SBP was 141 mm Hg while mean resting DBP was 79 mm Hg. Within-patient coefficient of variation was 8 percent for both SBP and DBP. [BMJ Innov 2018;doi:10.1136/bmjinnov-2017-000247]
Of note, no significant differences between the first and second day were seen for either SBP (142 vs 141 mm Hg, respectively; p>0.05) or DBP (79 vs 78 mm Hg, respectively; p>0.05).
The present data demonstrate that 2 days of 10 resting BP measurements provide reliable readings for clinical decision-making, the investigators noted. “Therefore, we believe it is appropriate to open debate as to whether [the high-frequency, short-duration protocol] could provide an alternative to the current NICE [National Institute for Health and Care Excellence] guidance,” they said. [BMJ 2011;343:d4891]
“Physiologically, it is reasonable to suggest that 10 measurements per day are likely to be more clinically valid than the existing 2-measurements-per-day recommendation,” the investigators pointed out.
Frequent measurements will better cover the myriad of factors known to affect BP (eg, behaviour-induced factors, endogenous and exogenous factors). This approach is also more likely to show some diurnal variation and circadian rhythm in view of the average within-patient coefficient variance of 9–11 mm Hg for SBP and 6 mm Hg for DBP.
“Indeed, the well-established 24-hour variance in both SBP and DBP is known to be increased in hypertensive patients compared with normotensive individuals. Therefore, a more frequent measurement protocol is likely to be of benefit to all patient groups,” they said.
The investigators also noted that the reading mean varies within the accuracy of the machine after 12 data points and that some patients do not manage to complete 10 readings in one day outside of the study. In these circumstances, a 2-day protocol offers a pragmatic compromise.
Importantly, the present study does not bid to alter current guidance and/or practice by itself, but instead attempts to offer evidence that suggests there may be a more cost-effective means of capturing the variance in BP reported in the currently preferred ambulatory monitoring technique.
“At the very least, there may be alternatives to current recommendations, which is important given that patients appear to appreciate a flexible approach to home BP monitoring,” the investigators said.