Figure 2.

Four-step approach to a trial with real-world data external comparators. Step 1 includes an assessment of sources of bias and exchangeability. Step 2 adjusts for measured confounders using analytical approaches. Step 3 uses quantitative bias analysis to quantify the impact of potential bias. Step 4, applicable only to augmented randomised controlled trials, combines outcomes between the internal and external comparator groups dependent upon the similarity of the two cohorts. The dotted line from Step 3 indicates that this step may be re-ordered or implemented iteratively