Wikipedia vs peer-reviewed medical literature for information about the 10 most costly medical conditions.

Context: Since its launch in 2001, Wikipedia has become the most popular general reference site on the Internet and a popular source of health care information. To evaluate the accuracy of this resource, the authors compared Wikipedia articles on the most costly medical conditions with standard, evidence-based, peer-reviewed sources.
Methods: The top 10 most costly conditions in terms of public and private expenditure in the United States were identified, and a Wikipedia article corresponding to each topic was chosen. In a blinded process, 2 randomly assigned investigators independently reviewed each article and identified all assertions (ie, implication or statement of fact) made in it. The reviewer then conducted a literature search to determine whether each assertion was supported by evidence. The assertions found by each reviewer were compared and analyzed to determine whether assertions made by Wikipedia for these conditions were supported by peer-reviewed sources.
Results: For commonly identified assertions, there was statistically significant discordance between 9 of the 10 selected Wikipedia articles (coronary artery disease, lung cancer, major depressive disorder, osteoarthritis, chronic obstructive pulmonary disease, hypertension, diabetes mellitus, back pain, and hyperlipidemia) and their corresponding peer-reviewed sources (P<.05) and for all assertions made by Wikipedia for these medical conditions (P<.05 for all 9).
Conclusion: Most Wikipedia articles representing the 10 most costly medical conditions in the United States contain many errors when checked against standard peer-reviewed sources. Caution should be used when using Wikipedia to answer questions regarding patient care.