As many of us know Google makes periodic changes to their search algorithm ostensibly to make search results better. Recently Google updated what they call the "Freshness Algorithm". Basically what this means is that Google is trying to make sure that search results for certain topics are "fresh", and it seems that Google will now be focusing somewhat on newer content. According to the official Google blog post on the subject which you can read here this change only affects 6-10% of searches [see the bottom of the article], but this change reinforces the age-old adage that "content is king".
Only time will tell how this change will affect search results for healthcare websites, and it seems that certain content is destined to be "not-fresh" by definition (you only graduated from dental school/medical school once). But what this change DOES suggest is that it may now be even more important to keep your eyes and ears peeled for the current trends in your field. If you are a dentist or dermatologist and you find that Botox becomes a very hot topic (more than it is already), then a guest article somewhere or a post on your own website or blog (which would be even better) about the subject may have more value now than before.
In summary, however, one thing never seems to change when it comes to Google's algorithm changes: you can't go wrong with well-written, high-quality content -- written, of course, by you!