In Reply We appreciate the interest in the Bisoprolol in COPD Study (BICS) from Drs Hsu and Lai. This was a pragmatic study to investigate the effect of bisoprolol on exacerbations in patients with COPD in the UK National Health Service, with any subgroup analysis considered exploratory and hypothesis generating. Moreover, the interpretation of any subgroup analyses in BICS is particularly limited because study recruitment was curtailed by the COVID-19 pandemic.
