[ggrothendieck]

Also they say they used the Fisher exact test and got a p value for mortality of 0.09 so it seems they were doing a two-sided test which is the default for fisher.test in R.

  ivm <- c(3, 247-3)
  con <- c(10, 249-10)
  m <- rbind(ivm, con)

  fisher.test(m)$p.value
  ## [1] 0.08809225

However, I think a one sided test could be justified and in that case it is significant at the 5% level.

  fisher.test(m, alternative = "less")$p.value
  ##        ivm 
  ## 0.04541928

[ggrothendieck]

Furthermore a test just twice as large would be sufficient to determine significance at the 1% level even with a two sided test if the same death rate continued to hold.

  ivm <- c(3, 247-3)
  con <- c(10, 249-10)
  m <- rbind(ivm, con)
  fisher.test(2*m)$p.value  # 2* so that it is twice as large
  ## [1] 0.008490957

[s1artibartfast]

Out of curiosity, which fisher test was used for the other endpoints?

[ggrothendieck]

The Mech Vent and ICU also used two sided tests.