Health and medical blog content and its relationships with blogger credentials and blog host.

People may utilize various sources when searching for health information, including blogs. This study sought to describe the nature of non-personal journal health and medical blog posts and the frequency of interactive blog feature use within these blogs, as well as to understand the quality of content found within health and medical blogs as determined by blogger expertise and blog host. A quantitative content analysis was performed on 398 blog posts from a constructed 1-week sample of posts in WebMD, Yahoo!Health Expert Blogs, and independently hosted blogs. Results show most health and medical blog posts highlighted and provided commentary pertaining to medical issues found in external media such as books, television, Web sites, magazines, and newspapers, whereas only 16% contained actual health or medical information. In addition, distinct differences in patterns of content were evident between credentialed and noncredentialed bloggers, as well as different blog hosts.