Statistical method was picked wrongly by this research
Paper Abstract | We recruited 86 participants for our study. Of these, 40 patients were randomly allocated to the control group, and 46 were randomly allocated to the tonsillectomy group. One patient in the control group and no patients in the tonsillectomy group had a severe episode of pharyngitis (difference 3%, 95% confidence interval [CI] −2% to 7%).
This, in a nutshell, is an RCT with a primary outcome as 1/40 vs. 0/46.
When any number of the four (as to this RCT primary outcome, they're  1, 39; 0, 46) greater than 5, we can use the normal approximation to solve a binomial distribution problem. The researchers use this method without the premise. Let's recreate their calculation by online calculators. (Upper Left. http://www.rossmanchance.com/ISIapplets.html Theory-Based Inference)
The right methods are Newcombe's method for 95% CI & Fisher's exact test for p-value. (Lower Right. http://vassarstats.net/prop2_ind.html )
Paper Short-term outcomes of tonsillectomy in adult patients with recurrent pharyngitis: a randomized controlled trial （Free Full Text）
Luckily, the fault didn’t change the conclusion. Good luck, all researchers!
