Feasibility, acceptability, and safety of a novel device for self-collecting capillary blood samples in clinical trials in the context of the pandemic and beyond.

Capillary blood self-collection, yielding slightly less than 500 μl, proves to be a safe and relatively painless method for adults and children, with high satisfaction and low failure rates. The puncture site and topical analgesia do not affect blood volume, but topical analgesia on the lower back could reduce pain.