There is an inherent tension between committing the fallacy of argument by authority and blindly trusting the word of someone just because they have an MD or lots of experience, and making the mistake of imagining that anyone who is reasonably intelligent and has access to the Internet can make complex medical decisions reliably (can we coin a new fallacy here; maybe argumentum ad hubris or argumentum ad internetum? ).
I spend most of my time as an advocate for science-based medicine pointing out how fallible doctors are. And I spend much of my time as a clinician wrestling with wacky, nonsensical theories my clients have deduced on their own or read on the internet. Both are legitimate problems in medicine. Doctors are often wrong, and they are more likely to be wrong in direct proportion to how much they rely on personal experience, mentors, and tradition instead of high-quality scientific research to make decisions. However, lay dilletantes who consult Dr. Google and then decide they know more about the causes and appropriate diagnostic or treatment interventions for their disease than their doctors are, I suspect, more often wrong than their doctors are.
I certainly research medical decisions I must make for myself and my family thoroughly, and I grill my doctors pretty hard about their rationale for their recommendations. However, I also give these recommendations a HUGE amount of weight in making my decisions, especially if they provide a rationale that indicates they have researched and thoughfully examined the issue themselves, rather than simply following an algorithm.
Ultimately, the pendulum has swung from the parternalistic days when doctors were inappropriately revered as all-knowing to the other extreme where everybody believs themselves to be as qualified to make medical decisions as their doctor regardless of what their own particular talent or expertise is. While I agree the patient should ultimately make the decisions when possible, since it is their health and life at stake, I think as patients we need at least as much humilty as we need as doctors about the reliability of our individual judgements.
So I’m not convinced “trust your doctor” is always bad advice, despite the bad advice I’ve seen doctors give. Any relationship with a professional specialist, from auto mechanic to tax accountant to surgeon, involves establishing trust in order to allow someone else to make decisions and take actions that have a potentially significant impact on you. There is some giving up of control needed for this to work. Patients should be informed, should ask probing questions, and ultimately should be able to make their own decisions, but they should bear in mind that they wouldn’t need a doctor at all if that person didn’t have knowledge and skills they don’t.