There were huge advances in public health in the 19th and early 20th centuries in the West (e.g. better handling of sewage, and reductions in food contamination). In addition, improvements in wealth have eliminated types of risks from everyday life. Again, though, the most visible differences were in the past (indoor plumbing and air conditioning are no longer considered luxury goods in the US). Do you believe that those kind of advances are still significant? If not, then what other factors aside from medicine do you believe are responsible for the fact that the long term trend of increasing life expectancies is continuing unabated as semi-anecdotal information suggests that medicine is improving (e.g. prognoses for patients with heart disease are much improved over the last 20-30 years).

These days, the available incremental public health improvements (e.g. food irradiation) are often rejected by the public which has preferred alternatives which are less likely to make a difference like organic food. Perhaps I’m missing changes, but it’s much harder to see major positive developments in public health in the last 20 years. Increased regulation of the environment, yes, but many of those regulations don’t have a clear and significant connection to health.

For good measure, consumer behavior is probably getting worse (with greater obesity more than offsetting lesser smoking).

(But no one ever seems to follow that sort of reasoning – people seemed wired to be altruistic towards the sick, but never altruistic when sick).

We all need to recognize that we have a strong emotional investment in the idea that doctors have nearly miraculous healing powers. It is extremely comforting to believe that if we get sick, modern medicine can get us well. The role of medicine in society and our social and political views on the topic are subject to bias as well.

Keep in mind that people have had these kinds of attitudes towards their shamen and healers throughout history, even in situations where we would recognize that the actual tools available to healers were extremely limited. These attitudes towards medicine evolved for a purpose but we need to look past our prejudices in order to clearly see the bias involved. I recommend approaching these topics with an uncluttered mind and trying to forget the things that “everyone knows” about doctors and medicine. Many of these commonly accepted beliefs are false or at least unjustified.

Also, preconceptions are often derived from indirectly related information which speaks inconclusively to the situation at hand. In a weak sense they may represent biases if we have a tendency to overrate the strength of indirect relationships. Ignoring that information isn’t right either, though, so the balancing act can be quite tricky.

I know questionning method detail selectively is a bias, and that Telnar has admitted bias, but I do feel it’s the natural question to ask of the study.

The post starts What type of hospital should you use if sick? and then cites a study that says that 1 in 400 people will die in the hospital. Immediately I thought “what are the odds of me dying personally?” – a variant of Telnar’s query, and a relevant one to the rest of the post.

Another question worth mentioning: if there is some initial medical error (or just an uncesseful procedure), then if it doesn’t kill you, it will leave you even more sick, staying in hospital for longer, and at the risk of dying (by a further medical error or just by not being cured). But that further death will be classified under another procedure. So can we say:
If a procdure is kill-or-cure, without any middle-ground, we should consider it relatively safer than those with a middle-ground.

Still, while that bias has the potential to distort the way I handle evidence, not all of this preconception is bias. Medical technology clearly does improve over long periods (life expectancies at birth have been rising by on the order of 1 year for every 5 that pass, of late). The relevant question is how that manifests in the shorter run since (without data that I don’t have) I can’t rule out the possibility that treatments are sorted by quality well after they are first launched. Still, if that scenario were common, I’d expect to have heard more about inferior treatments which were weeded out — if only because of the volume of lawsuits they would generate.

So, how should one approach thinking about bias when it seems to point in the same direction as the available evidence, but that evidence is weak?