Worldwide, U.S., and U.S. NIH-funded cardiovascular research articles, 1996–2006, by article study characteristics and methodology.

Articles may belong to more than one category, thus the sum of the categories do not necessarily equal the total. Unspecified, general research are research articles with no specified subtype. Miscellaneous articles are journal articles without scientific content, such as bibliographies, biographies, comments, letters, historical articles, guidelines, editorials, news, indices, legal cases, interviews, and consensus statements. Additional information on publication characteristics and methodologies is available at the National Library of Medicine website, at http://www.nlm.nih.gov/mesh/pubtypes2008.html.

一篇文章可隶属于多个类别，因此各类别文章的数量之和未必等于总文章数。未指定子类别的通用研究，即无明确子类型的研究类文章。杂项文章指不含科学内容的期刊文章，涵盖书目、传记、评论、信函、历史文章、指南、社论、新闻、索引、法律案例、访谈及共识声明等类型。有关出版物特征与研究方法的更多信息，可访问美国国家医学图书馆（National Library of Medicine）官网：http://www.nlm.nih.gov/mesh/pubtypes2008.html。