Letter: biologics are effective in neutralising the detrimental effect of smoking on the natural course of Crohn's disease - authors’ reply

We thank Savarino et al. for taking the time to read our paper,1 and for their comments.2 We agree that anti-tumour necrosis factor-α drugs are effective in Crohn's disease,3 but it is important to remember that these drugs may have serious side effects.4, 5 In addition, as we stated in our paper,1 although the studies we included were not randomised, using these data to calculate a number needed to treat (NNT) suggested that only seven people...