Response by Abrahami et al to letter regarding article ‘Proton pump inhibitors and risk of colorectal cancer’

We thank Chen Dong et al 1 for their interest in our study on the use of proton pump inhibitors (PPIs) and colorectal cancer incidence.2 We have responded to their comments as follows. While there may be some differences between PPI and histamine-2 receptor antagonist (H2RA) users, these two drug classes are used across similar indications in the real-world setting.3 Thus, the use of H2RAs as an active comparator provides a clinically meaningful comparison for physicians deciding whether to treat patients with gastric disorders with a PPI or H2RA. This is certainly a better approach than comparing PPI users to non-users. Furthermore, we included all approved and off-label indications for acid suppressant drug use in our propensity score models to minimise residual confounding by disease severity. After applying propensity score weights, our population was well balanced on all …