Figure 3.

Percentiles of (A) continuous or binary variables and (B) categorical variables in the trial, in the context of regional variation (representativeness of SLS COPD). Variables considered unusual are shown as grey triangles. BMI, body mass index; COPD, chronic obstructive pulmonary disease; CPRD-xGM, Clinical Practice Research Datalink outside of greater Manchester; CVD, cardiovascular and cerebrovascular diseases (specifically heart failure, myocardial infarction and stroke); FEV₁, forced expiratory volume in 1 s; FVC, forced vital capacity; GOLD, Global initiative for chronic Obstructive Lung Disease; GORD, gastro-oesophageal reflux disease; MRC, Medical Research Council; SLS COPD, Salford Lung Study in chronic obstructive pulmonary disease.