A 2007 study examined a sample of Wikipedia pages about the most frequently performed surgical procedures in the United States, and found that 85.7% of them were appropriate for patients and that these articles had "a remarkably high level of internal validity".[7] However, the same study also raised concerns about Wikipedia's completeness, noting that only 62.9% of the articles examined were free of "critical omissions".[7] A 2008 study reported that drug information on Wikipedia "has a more narrow scope, is less complete, and has more errors of omission" than did such information on the traditionally edited online database Medscape Drug Reference.[8] A 2010 study found that Wikipedia's article on osteosarcoma was of decent quality, but that the National Cancer Institute (NCI)'s page was better.