Cumulative meta-analysis is a powerful method used to analyze and interpret the evolving results of multiple randomized controlled trials (RCTs) over time. The figure illustrates two methods of presenting cumulative meta-analysis results for assessing the effectiveness of oral β-blockers in reducing mortality after myocardial infarction [1]. 

The left panel depicts the results of 17 individual RCTs, showcasing the odds ratio for each trial and their respective confidence intervals on a log scale. While many trials appear to have statistically non-significant outcomes individually, the pooled analysis provides a clearer and more meaningful estimate of the treatment’s effectiveness [3].