Fig. 5

Bland Altman plot of log ratio of standard errors of the standardised meta-analytic effect estimates (y-axis) vs average of the standard errors (x-axis), for each pairwise comparisons of ITS analysis and meta-analysis method combination (top row of the label indicates the ITS analysis methods, bottom row indicates the meta-analysis method, e.g., OLS ITS DL MA is OLS ITS analysis with DerSimonian and Laird between-study variance meta-analysis). The top triangle (green points) presents the immediate level-change [log ratio calculated as log(column method / row method)], and the bottom triangle (blue points) presents the slope-change per month [log ratio calculated as log(row method / column method)]. Horizontal orange lines depict the average, dashed orange lines depict the 95% limits of agreement (calculated as the mean ± 1.96*standard deviation of the log(ratio)). Vertical grey line indicates an average of zero, while the horizontal grey line indicates a log(ratio) of zero. The coloured boxes indicate cells that compare meta-analysis models (i.e., fixed- vs random-effects models)[yellow boxes], ITS analysis methods when random-effects meta-analysis was used (black boxes), between-study variance estimators (blue boxes) and confidence interval methods (red boxes). The solid coloured boxes indicate comparisons of level-change and dashed boxes indicate slope-change per month. DL DerSimonian and Laird, HKSJ Hartung-Knapp/Sidik-Jonkman, ITS interrupted time series, OLS ordinary least squares, REML restricted maximum likelihood, WT Wald-type