I'm a little late to this, but Clinical Correlations' Suzanne MacFarland has written an excellent high-level overview of how patient self-diagnosis, often facilitated by search-engine ubiquity, is influencing doctor-patient interactions. She writes:
There is a stranger in the clinic room, and it is not your patient. This stranger is a multifaceted, opinionated entity with likely conflict-of-interest. This new acquaintance has already spoken to your patient and influenced the direction of this visit in the form of health statistics, symptom explanations, and feared complications. Now your patient wants to know what you think. In an age when patients will often have diagnosed their problem before they walk through a clinic door, the provider may start to feel overwhelmed by a third entrant into the patient-provider dialogue: the elusive online source.
MacFarland reminds readers that most U.S. adults conduct health-related searches on the web, and she points out that health information on the web is often inaccurate or incomplete or suffers from a conflict-of-interest. And she offers some potential solutions. If you want a primer on how web-powered self-diagnosis might be affecting doctor-patient conversations, the entry is worth reading.