Randomized Controlled Trial Comparing Automated Office Blood Pressure Readings After Zero or Five Minutes of Rest

The purpose of the Zero to Five study was to compare automated office blood pressure (AOBP) readings obtained after either 0 or 5 minutes of antecedent rest in relation to the awake ambulatory blood pressure. AOBP is recommended in different jurisdictions following either a 0- or 5-minute rest. This was a prospective, randomized, 2 arm, trial with blinded outcomes, recruiting adult patients referred for ambulatory blood pressure monitoring (ABPM). Participants had an AOBP measurement performed according to clinical practice guidelines with an OMRON HEM-907XL set to measure after 0 or 5 minutes of rest. The primary outcome was the difference between the mean AOBP and mean awake ABPM in the 0-minute wait group versus that in the 5-minute wait group. The study enrolled 618 participants, mean age 57.1 years, 52% women. For the 0-minute rest group, the mean AOBP was 141.2/83.1 (17.1/12.1 mm Hg) and the awake ABPM was 141.3/83.8 (16.1/10.2 mm Hg), with difference -0.02/0.52 (17.4/11.4 mm Hg). For the 5-minute rest group, the mean AOBP was 138.2/81.7 (16.9/12.4 mm Hg) and the awake ABPM was 143.4/83.6 (17.3/10.3 mm Hg), with difference -5.16/-0.8 (18.6/11.6 mm Hg). The difference of differences in systolic blood pressure (AOBP-awake ABPM) for the 0 versus the 5-minute wait group was 5.1 mm Hg (95% CI, 2.3-8.0, P=0.005) with the 0-minute AOBP measurement closest to the awake ABPM. The Zero to Five study demonstrated that a wait time of 0 minute before an AOBP measurement was closer to the daytime ABPM result than a 5-minute wait before the AOBP.

Automated summary

The Zero to Five study demonstrated that a 0-minute wait before an AOBP measurement was closer to the awake ABPM result than a 5-minute wait.