A 2015 study comparing the coverage of the autism-vaccine controversy on several websites found that Wikipedia's articles were broadly pro-vaccine. The study attributed this pro-vaccine stance to "this highly controversial topic attracting committed editors who strictly enforce the requirements for academic references."[26] A 2016 study found that drug information on Wikipedia was less accurate and complete than that on the medical reference site Micromedex.[27] A 2017 study compared the accuracy of Wikipedia articles about the 33 most popular medications with medication guides to the accuracy of their medication guides.