Clinical Biostatistics: Geometric mean length of hospital stay exercise, suggested answer 7

7. In the body of the paper, we read that “seven inpatients in the standard practice arm died during the study (0% (0 of 55) early computed tomography v 11% (7 of 63) standard practice, P=0.014)”. In the discussion we read “Caution is needed in generalising our results as mortality was not an a priori end point of our study.” What would you conclude from this?

Suggested answer

If mortality was not an intended end point, the test has been done only because a difference between treatment groups was observed. The caution is entirely justified. However, in the abstract, the authors include deaths during the study among three “main outcome measures”. This is contradictory. I think I believe the discussion rather than the abstract.

We could not apply a Bonferroni correction to the P value, because we have no idea how many tests we would have to take into account.

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