Avoiding misleading information: A study of complementary medicine online information for cancer patients

Health misinformation can severely affect human behaviour, especially in controversial areas such as that of complementary medicine. A cross-sectional observational study was conducted on 16 web pages to identify different kinds of falsehoods, to estimate the risk of running into deceptive information, and to observe the differences among experts' and one layperson's assessments. Almost all analyzed claims were unfounded. Unexpectedly, the experts agreed more often on considering analyzed scientific statements to be correct rather than incorrect. However, half of the time, the experts did not agree, so that the correctness of some claims remained undefined. A statistically significant risk of running into unfounded information and incorrect or undefined claims was found. There was a low agreement between the expert and layperson evaluation. The results of this study can help consumer health librarians to interpret cues of potentially misleading information about controversial issues and thereby improve their information and communication services.