3. Treatments you will pay as much as possible for. This category may not be distinct from category 2 for a single adult with no family.
4. Treatments which have a high enough out-of-pocket cost, that it is a factor in the consumption decision.
A personal example falls into category 4. Two migraine aborting treatments work for me, rizatriptan in tablet form and sumatriptan in injection form. The first requires about 3 hours for full effect, whereas the second takes under an hour. The differences in cost between insurance an no insuranceare around $25 and $100, respectively.
In the context of missing a full day of work, even the $100 falls into category 2. However, during unemployment, on a weekend or an evening, even $25 is enough that it's not "free," but even the $100 isn't so much that I wouldn't pay for it out of pocket, depending on the circumstances.
These treatments may well reduce my "health" by any objective measure, including lifespan, but they certainly improve my productivity and quality of life, something the article seems to ignore.
1. Marginal treatments, or treatments you will not pay for out of pocket, but will consume if they are free. These comprise 30% or more of treatments.
2. Non-marginal treatments, which you will buy regardless of whether insurance pays for them.
Your son's friend's hemophilia treatments sound like they fall into category 2. The article argues that category 1 treatments are useless (equally likely to harm or help you).