Fig. 1

Figure 1 Framework and flowchart of MR. (A)Framework for investigating the causal effect of lung function (FVC, PEF, FEV1/FVC and FEV1) on OP. (B) Flowchart of the sequential steps taken to investigate the causal effect of lung function (FVC, PEF, FEV1/FVC and FEV1) on OP.