Thoracic cutaneous sensory loss in volunteers: are we adequately assessing non-inferiority?

We have read the study by Nielsen et al,1 a non-inferiority cross-over clinical trial comparing single-injection (SITPB) versus multiple injections (MITPB) variants of the intertransverse process block (ITPB). The study concludes that SITPB is not inferior to MITPB in terms of number of dermatomes with sensory loss of the hemithorax in volunteers.