Abstract Body: Background
Standardized automated office blood pressure (AOBP) measurement is now widely accepted as the preferred method for monitoring blood pressure (BP). However, disagreements persist amongst expert societies as to the need to perform AOBP in an unattended manner, where the patient is left alone in a quiet room. In 2019, two meta-analyses aiming to quantify the differences between unattended and attended BP showed opposite results. prompting the publication of several more studies on this subject. Our objective was thus to reassess the BP differences between unattended and attended AOBP when performed with the same device and an identical measurement protocol.

Methods
This systematic review with meta-analysis was conducted according to the PRISMA guidelines and is registered on PROSPERO. Studies were included if both unattended and attended AOBP were measured on the same participants in a randomized or alternating sequence manner during a single visit with the same device and an identical measurement protocol apart from attendance status. Four databases were searched (Embase, Medline, Web of Science, Google Scholar). The primary outcome was the difference between unattended and attended systolic (SBP) and diastolic (DBP) BP, expressed as weighted mean differences (95% confidence interval) using random-effects models.

Results
From 8,088 screened studies, data was extracted from 15 studies which met the inclusion criteria (n=1,747 participants). In the pooled analysis, the attended compared with unattended BP was higher for SBP by 2.7 mmHg (95%CI 0.6 to 4.7) and DBP by 0.9 mmHg (95%CI 0.1 to 1.8). In leave-one out analyses, results were similar except when excluding the study with the most extreme BP difference (Chotruangnapa 2023) where the difference became non-significant.

Conclusion
Standardized attended AOBP measurements result in slightly higher readings than unattended AOBP. Whether such small differences translate into clinically significant changes in management of BP remains uncertain. Therefore, standardized attended AOBP could be viewed as a reasonable option for BP measurement in a real-life clinical setting.