Accuracy and readability of cardiovascular entries on Wikipedia: are they reliable learning resources for medical students?

Objective To evaluate accuracy of content and readability level of English Wikipedia articles on cardiovascular diseases, using quality and readability tools. Methods Wikipedia was searched on the 6 October 2013 for articles on cardiovascular diseases. Using a modified DISCERN (DISCERN is an instrument widely used in assessing online resources), articles were independently scored by three assessors. The readability was calculated using Flesch-Kincaid Grade Level. The inter-rater agreement between evaluators was calculated using the Fleiss scale. Results This study was based on 47 English Wikipedia entries on cardiovascular diseases. The DISCERN scores had a median=33 (IQR=6). Four articles (8.5%) were of good quality (DISCERN score 40-50), 39 (83%) moderate (DISCERN 30-39) and 4 (8.5%) were poor (DISCERN 10-29). Although the entries covered the aetiology and the clinical picture, there were deficiencies in the pathophysiology of diseases, signs and symptoms, diagnostic approaches and treatment. The number of references varied from 1 to 127 references; 25.929.4 (mean +/- SD). Several problems were identified in the list of references and citations made in the articles. The readability of articles was 14.3 +/- 1.7 (mean +/- SD); consistent with the readability level for college students. In comparison, Harrison's Principles of Internal Medicine 18th edition had more tables, less references and no significant difference in number of graphs, images, illustrations or readability level. The overall agreement between the evaluators was good (Fleiss 0.718 (95% CI 0.57 to 0.83). Conclusions The Wikipedia entries are not aimed at a medical audience and should not be used as a substitute to recommended medical resources. Course designers and students should be aware that Wikipedia entries on cardiovascular diseases lack accuracy, predominantly due to errors of omission. Further improvement of the Wikipedia content of cardiovascular entries would be needed before they could be considered a supplementary resource.