Assessing the quality, suitability and readability of internet-based health information about warfarin for patients

Warfarin is a high-risk medication where patient information may be critical to help ensure safe and effective treatment. Considering the time constraints of healthcare providers, the internet can be an important supplementary information resource for patients prescribed warfarin. The usefulness of internet-based patient information is often limited by challenges associated with finding valid and reliable health information. Given patients' increasing access of the internet for information, this study investigated the quality, suitability and readability of patient information about warfarin presented on the internet.

Previously validated tools were used to evaluate the quality, suitability and readability of patient information about warfarin on selected websites.

The initial search yielded 200 websites, of which 11 fit selection criteria, comprising seven non-commercial and four commercial websites. Regarding quality, most of the non-commercial sites (six out of seven) scored at least an 'adequate' score. With regard to suitability, 6 of the 11 websites (including two of the four commercial sites) attained an 'adequate' score. It was determined that information on 7 of the 11 sites (including two commercial sites) was written at reading grade levels beyond that considered representative of the adult patient population with poor literacy skills (e.g. school grade 8 or less).

Despite the overall 'adequate' quality and suitability of the internet derived patient information about warfarin, the actual usability of such websites may be limited due to their poor readability grades, particularly in patients with low literacy skills.