If you didn't care to know anything about finance, and you hired a financial adviser (paid hourly, not through commissions, of course) you would be happy to have him simply tell you to invest all of your assets into a Vanguard life cycle fund. But you may then be surprised that a different adviser told one of your contemporaries that the approach was oversimple and that you should have several classes of assets in your portfolio that are not included in the life cycle funds, such as gold or commodities. In light of the discrepancies, you may conclude that to make the best economic choices for yourself, you need to understand finance and the data upon which the advisers are basing their recommendations.Making medical decisions optimally is akin to making economic decisions and is founded on a simple framework: EUT, or Expected Utility Theory. To determine whether to pursue a course of action versus another one, we add up the benefits of a course multiplied by their probability of accruing (that product is the positive utility of the course of action) and then subtract the product of the costs of the course of action and their probability of accruing (the negative utility). If utility is positive, we pursue a course of action, and if options are available, we pursue the course with the highest positive utility. Ideally, anybody helping you navigate such a decision framework would tell you the numbers so you could do the calculus. Using the finance analogy again, if the adviser told you "Stocks have positive returns. So do bonds. Stocks are riskier than bonds" - without any quantification, you may conclude that a portfolio full of bonds is the best course of action - and usually it is not.
I regret to report that that is exactly what clinical practice guideline writers do: provide summary information without any numerical data to support it, leaving the practitioner with two choices:
- Just do as the guideline writer says
- Go figure it out for herself with a primary data search
