An appendectomy is the white bread of surgeries. It’s common, it’s low-risk, and it only takes an hour or two to perform. Even the children’s-book character Madeline had her appendix out, and it was so not a big deal that at the end of the book, the other girls who lived in the “old house in Paris that was covered with vines” complained that they wanted to get their appendixes out too, so they could get presents and have a cool scar.

But still, any surgery involves cutting someone open and sewing them back up again. And no matter how quotidian the procedure, when you open somebody’s body up, there’s a risk of infection.

To help reduce this risk, many surgical patients are given prophylactic antibiotics. But with the rise of antibiotic-resistant bacteria, that strategy may become less and less effective. A new study published in The Lancet Infectious Diseases by researchers at the Center for Disease Dynamics, Economics, and Policy examines just how much less.

The study looks at two types of meta-analyses (making it a meta-meta-analysis): of infection-related deaths, and of the effectiveness of antibiotic prophylaxis in preventing infections for chemotherapy and the 10 most common surgical procedures in the United States.