"As many as 98,000 people die in hospitals each year as a result of medical errors" - doesn't feel implausible, but a quick Google for US annual death rate - it turns out to be twice the death rate for suicide. This document seems to contradict the finding, I'd check out the reference
This number may not only include US data.
Indeed. And how do we find that out?
What I'm trying to figure out is, how to I determine whether a source I'm looking at is telling the truth? For an example, let's take this page from Metamed: http://www.metamed.com/vital-facts-and-statistics
At first glance, I see some obvious things I ought to consider. It often gives numbers for how many die in hospitals/year, but for my purposes I ought to interpret it in light of how many hospitals are in the US, as well as how many patients are in each hospital. I also notice that as they are trying to promote their site, they probably selected the data that would best serve that purpose.
So where do I go from here? Evaluating each source they reference seems like a waste of time. I do not think it would be wrong to trust that they are not actively lying to me. But how do I move from here to an accurate picture of general doctor competence?