Important drug safety information on the Internet: Assessing its accuracy and reliability

The Internet is becoming increasingly important as a source of health-related information, but the accuracy and reliability of information presented on the world wide web is debated. We aimed to assess whether important, recent drug safety information is accurately reflected on Internet sites. We evaluated whether major warnings issued by the US FDA between October 1, 2000 and September 30, 2001 on severe and life-threatening drug toxicity were mentioned 4-16 months later in the top ten web pages identified for these drugs by each of seven different search engines. We examined predictors of precise mention of the FDA warnings using logistic regressions. Twenty major safety warnings on 21 drugs (including three withdrawals) were eligible for the study. Among 519 different pertinent web pages retrieved (16-32 for each drug), precise mention of the safety issue was made in only 165 (31.8%). Best rates of precise mention were seen in web sites sponsored by attorneys (79.4%), in physician-oriented web pages (65.5%) and for withdrawn drugs (57.9%). In addition to these factors, better coverage of the FDA warnings was independently seen when no other adverse effects from the same organ system was mentioned (p < 0.001), while coverage was worse when there was no date on the site and web page (p = 0.020), and when the site owner could not be classified or was unknown (p = 0.014). Important safety warnings are inadequately covered in the majority of web pages. This deficiency creates a source of potentially harmful misinformation for health consumers.