Attended Versus Unattended Automated Office Blood Pressure: A Systematic Review and Meta-analysis.

Introduction: Automated office blood pressure (AOBP) has been proposed for blood pressure (BP) assessment in the office because it shows a strong association with the awake ambulatory BP. However, it remains unknown whether the presence or absence of an observer modulates AOBP readings.
Aim: To determine the difference between unattended and attended AOBP measurements through systematic review and meta-analysis.
Methods: We searched the PubMed and the Cochrane Collaboration Library and we screened the references' list of relevant reports to identify potentially eligible articles. For included studies, quality was assessed by using the Quality Assessment for Diagnostic Accuracy Studies 2. The weighted pooled BP difference with 95% confidence interval (CI) between unattended and attended AOBP was estimated under the random effects model.
Results: Twelve studies (1762 subjects) were included. The systolic and diastolic BP difference between unattended and attended AOBP measurements was - 3.66 (- 6.58 to - 0.75) and - 1.67 (- 2.78 to - 0.55) mmHg, respectively. Heterogeneity across studies was high (I ²  = 97,1% for systolic and I ²  = 89% for diastolic BP, P < 0.001) and was partially determined by the sequence of performing unattended and attended BP measurements, the device used for AOBP, the geographic region in which studies were performed and the presence of a resting period before unattended AOBP.
Conclusions: Due to the high heterogeneity, we cannot rely on the weighted pooled estimate. However, the available evidence suggests that attended AOBP yielded higher systolic and diastolic BP levels and it seems that the procedural methodology determines partially the statistical heterogeneity across studies.