Impact of choice of selection methods on ability to replicate trial results for the analysis of exacerbations, in people exposed to fluticasone propionate (FP)-salmeterol (SAL) versus people exposed to SAL

Rate ratioSubjects per exposure group n
TORCH trial10.88 (0.81–0.95)1524
CPRD non-interventional selection method#
 TORCH inclusion and exclusion criteria and matched to TORCH10.85 (0.74–0.97)991
 TORCH inclusion and exclusion criteria only10.87 (0.81–0.94)3225
 No TORCH criteria or matching11.64 (1.52–1.77)5951

CPRD: Clinical Practice Research Datalink. #: SAL and FP-SAL groups were propensity score matched for all selection methods; : as per the main analysis and presented in table 4.