"OpenAlex had the best coverage (98.6%), followed by Semantic Scholar (98.3%), Embase (96.8%), and PubMed (93.0%). However, 90.5% of all articles were retrievable from all four databases. All articles that were not retrievable from OpenAlex and Semantic Scholar were either assessed as medium or high RoB. In contrast, both Embase and PubMed missed articles that were of high quality (low RoB)"
https://www.jclinepi.com/article/S0895-4356(25)00122-2/fulltext?rss=yes