Figure 2.

Does age interact with the effect of antihypertensive treatment on systolic blood pressure? Findings from an IPD meta‐analysis of 10 trials, showing difference in results based on across‐study (solid line) and within‐study (dashed lines) information. Across‐study relationship (from meta‐regression of trial's treatment effect estimates vs mean age) denoted by gradient of solid line. Participant‐level relationship using within‐study information (ie, treatment‐sex interaction within each trial) denoted by gradient of dashed lines and the summary gradient (${\widehat{\mathrm{\gamma }}}_{\mathrm{W}})$ is −0.036 (95% CI: −0.19 to 0.12). Each block represents one trial, and the block size is proportional to the size of the trial.