A while ago, I wrote an article summary of a study which compared the mapping abilities of different MEDLINE interfaces – PubMed, Ovid, GratefulMED, and others. Some of these have since become defunct, and I have not been able to find a follow-up study. I did, however, find an article from 2011 which compares the sensitivity of PubMed and OVID searches. The searchers used the proper MeSH terms, synonyms, and main concepts to systematically search OVID and PubMed. A total of 17 relevant results turned up in OVID, while 18 were retrieved with PubMed, one of which hadn’t been indexed by OVID yet. Overall, PubMed seemed more the more sensitive tool. This was slightly offset by the difficulty of searching PubMed, which the authors found took more experience to search effectively. But taking the facts that PubMed is more sensitive and free together, it still seems to be the better choice overall.