Funnel plot for studies reporting systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and mean arterial pressure (MAP). Visual inspection and Egger test for bias do not show significant publication bias. Standard error was calculated as SD of bias divided by square root of the sample size. Studies reporting bias of SAP (n = 25), DAP (n = 24), and MAP (n = 26) were plotted on the X-axis and standard errors are plotted on the Y-axis.