Online health self-assessments are gaining in popularity. Not because I've seen a stat, but instead I see hospitals and other health organizations tweeting links more and more often. I also expect we will see increasing popularity of these offerings as individuals take a more active role in their healthcare and innovative organizations meet the evolving needs of their consumers.
Here are a few good ones. If you know of others, please leave a comment and include a link.
Banner Health Snakebite Quiz
Canadian Mental Health Association Mental Health Test Your Knowledge
Chester County Hospital Cardiac Risk Assessment