Correction to: Trials 21, 532 (2020)

https://doi.org/10.1186/s13063-020-04427-7

After publication of the original article [1], the authors have notified us that their originally submitted Fig. 1 was mistakenly replaced with an incorrect figure during editing.

  • Originally published Fig. 1:

figure a
  • Correct Fig. 1:

figure b

The Publisher apologizes for this error and any confusion caused.

The original article has also been updated.