Cochrane review

Cochrane is an international, independent network that produces systematic reviews of health care. Its reviews follow a protocol published in advance, search broadly for trials, and rate how certain the evidence is using the GRADE system, from high to very low. Cochrane Oral Health covers dentistry.

A Cochrane review is often the best single place to start on a clinical question, and it is candid when the trials are not good enough to answer it. Its value depends on the trials underneath. In Ryan's article on recall intervals, the Cochrane review can call its finding high-certainty because it rests on one large, well-run trial; on other questions, the same method returns low certainty because the studies are small or inconsistent.

Ryan's research articles cite Cochrane reviews where they exist and say what certainty they assigned, so a reader can tell a settled answer from an open one.