I'll start.
In terms of costs, I think Andrew is going to be able to answer this question much more effectively than I am, but I'll give you an example.
The second most common reason for a drug-related adverse event when a patient presents to an emergency department is an antibiotic-related adverse event. The costs—and the health system costs associated with that—are significant. Unintended consequences, such as Clostridium difficile, the superinfection that can arise with overuse of antibiotics, have significant costs.
I can't necessarily put numbers to those costs. I don't have those off the top of my head. I'm sure Andrew can expand on this, but those are two examples that I'd offer you.