Background Thousands of web searches are performed related to transarterial chemoembolization (TACE), given its palliative role in the treatment of liver cancer. Objective This study aims to assess the reliability, quality, completeness, readability, understandability, and actionability of websites that provide information on TACE for patients. Methods The five most popular keywords pertaining to TACE were searched on Google, Yahoo, and Bing. General website characteristics and the presence of Health On the Net Foundation code certification were documented. Website assessment was performed using the following scores: DISCERN, Journal of the American Medical Association, Flesch-Kincaid Grade Level, Flesch Reading Ease Score, and the Patient Education Materials Assessment Tool. A novel TACE content score was generated to evaluate website completeness. Results The search yielded 3750 websites. In total, 81 website entities belonging to 78 website domains met the inclusion criteria. A medical disclaimer was not provided on 28% (22/78) of website domains. Health On the Net code certification was present on 12% (9/78) of website domains. Authorship was absent on 88% (71/81) of websites, and sources were absent on 83% (67/81) of websites. The date of publication or of the last update was not listed on 58% (47/81) of websites. The median DISCERN score was 47.0 (IQR 40.5-54.0). The median TACE content score was 35 (IQR 27-43). The median readability grade level was in the 11th grade. Overall, 61% (49/81) and 16% (13/81) of websites were deemed understandable and actionable, respectively. Not-for-profit websites fared significantly better on the Journal of the American Medical Association, DISCERN, and TACE content scores. Conclusions The content referring to TACE that is currently available on the web is unreliable, incomplete, difficult to read, understandable but not actionable, and characterized by low overall quality. Websites need to revise their content to optimally educate consumers and support shared decision-making. Trial Registration PROSPERO International Prospective Register of Systematic Reviews CRD42020202747; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020202747

BACKGROUND Transarterial chemoembolization (TACE) is the reason for thousands of web searches given its palliative role in liver cancer treatment. OBJECTIVE The purpose of our study is to assess the reliability, quality, completeness, readability, understandability and actionability of websites providing information on TACE for patients. METHODS The 5 most popular keywords pertaining to TACE were searched in Google, Yahoo and Bing. General website characteristics as well as presence of Health on the Net (HON) code certification were documented. Website assessment was performed using the following scores: DISCERN, Journal of the American Medical Association (JAMA), Flesch-Kincaid Grade Level (FRES), Flesch Reading- Ease Score (FKGL) and Patient Education Materials Assessment Tool (PEMAT). A novel TACE-specific content score was designed to evaluate website completeness. RESULTS The search yielded 3750 websites. Eighty-one website entities met inclusion criteria. HON code certification was present in 11.5% of website domains. Authorship was absent in 88% of websites, whereas sources were absent in 83% of websites. Medical disclaimer was not provided in 31% of websites. Date of publication or of last update was not listed in 58% of websites. Median DISCERN score was 47 (IQR 40.5 – 54.0). Median TACE-content score was 35 (IQR 27 – 43). Median readability grade level was in the 11th grade. Sixty percent and 16% of websites were deemed understandable and actionable, respectively. Not-for-profit websites fared significantly better on JAMA, DISCERN, and TACE- content scores (p <0.05). CONCLUSIONS The content referring to TACE that is currently available online is unreliable, incomplete, difficult to read, understandable but not actionable, and characterized by low overall quality. Websites need to revise their content in order to optimally educate consumers and support shared decision-making.