QUALITY: The sociology & economics of practice patterns & decision aids

More from Matthew at the FIMDM conference

David Jones, Harvard medical historian on revascularization

Why do you need a randomized clinical trial (RCT)? From the 1960s surgeons could show that CABGs opened veins (removed plaque) so why was there a need?  As it turns out, it’s not the large plaque in the vein that kills you but instead it’s the smaller “fragile” plaque which ruptures & causes heart attacks—it’s not the big blockage that causes the heart attack. Angioplasty (PCI) doesn’t get that fragile plaque out, so it shouldn’t be used as much as it is. Of course that’s not what happened. We’d already been shown that by Lee Lucas that there was lots more angioplasty when this theory became well known

However in fact the theory about these fragile plaque rupture was in the obscure cardiology pathology literature in the 1960s but didn’t break through to the mainstream cardiologist opinion until the late 1990s.

So the question is, why didn’t that break through earlier? Jones’
theory is that CABG techniques came on at the time that these theories
were being postulated, and the cardiac surgeons believed that the large
plaque blockage was that caused heart attacks. So the practice (esp
after more imaging developments) “informed” the surgeons that it
worked. But the problem is that plaque rupture didn’t fit that model.
Worse the model suggests that every male above 35 have a fragile plaque
just waiting to blow, and you wouldn’t know! It also doesn’t lend
itself well to treatment — so what do you do? So that model leaves a
lot more people in trouble, with not much to do, and (unspoken by
David) cardiac surgeons and cardiologists want to do something!

Meanwhile, no one went to look at impact of neurological dysfunction
caused by the surgery (putting people on a heart-lung machine during
the procedure). In fact this was a really high number—up to 60% having
some neurological problem. But this was recognized very slowly—first
reported in 1954! Only really came out in the late 1990s! By then of
course people are doing surgery on beating hearts, or doing more
angio—early data suggests that this makes little difference to
neurological function. And of course the heart condition is right in
front of the surgeon, while the neuro risk is later.

Then there’s the huge geographic variation in CABGs. How have
cardiac surgeons/ cardiologists responded? Most people say that it’s
just financially driven. But David wants to go deeper and find out more?

Very short, David Meltzer, Univ Chicago, on economics of
decision aids. His research shows that decision aids can increase or
decrease costs—studies are small, but no clear message that they work
to decrease costs, and many of the current aids are on low ticket
items—where the impact cant be that big one way or the other. The
welfare effect of decision aids is much more positive. My guess is that
this isn’t probably the exact message that Health Dialog (which funds
FIMDM) wanted to hear!

David Wennberg, Health Dialog, got onto the topic—does
disease management save any money? The literature sucks, so they did an
RCT on use of decision aids with a couple of health plans—HealthNet and
Highmark Blues in Pennsylvania who found 7 big varied employee groups
with 180K eligble members total. They looked at households, some of
whom got standard care, others got that plus the decision aid
intervention from Health Dialog….all ended up being essentially same
health, risk & cost profiles. They looked at five groups by health
status those with 1) chronic condiitions, 2) preference sensitive (e.g.
back surgery), 3) chronic PLUS preference sensitive, 4) other coachable
stuff (obesity), 5) the rest.

So what happened? For those groups there were reductions in
hospital admissions of between 2.9 – 13.4% reduction in visits. ER
visits was about the same, and marginal change in physician services.
Overall significant reduction in surgical procedure in these groups
(about 30% less PCI). The savings were overall $10 pmpm about 5% of
costs. Of that savings, essentially all the savings were in inpatient
& outpatient surgery, but drug costs went up. So you can
increase drug costs, while reducing over all costs. Of the groups the
chronic and chronic plus groups provided 60% of those cost savings. BUT
these were gross savings—the actual savings were a little lower (about
1% less). So it looks like it worked, and also worked about the same
percentage in different cost regions.

But if you assume that this means you can buy Health Dialog
stock and get rich, sadly British insurer BUPA beat you to it! Of
course,they can still get Pfizer to pay for the next one! (Just

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  1. Just one technical correction about the first part of your good post – the plaque forms in arteries, not veins. The only time it would form in veins in the heart is when it, sometimes, forms in veins used to bypass blocked coronary arteries. As for your comments on the literature, they support the point that things which may seem intuitively obvious in medicine are not necessarily true. This is behind some seemingly inexplicable findings now that we are actually engaging in evidence-based medicine – that lowering LDL cholesterol may NOT be the one necessary and sufficient ingredient for preventing heart disease, for example, or that PCI with stents may improve immediate outcome, but not necessarily long term survival in all groups of patients. These things will take years to sort out. As a poor statistician, I find myself frustrated by reading that seemingly conflicting studies are explained by differences in their statistical power to answer various questions. It seems like the statisticians are the REALLY important people running these studies – or that all medical students should take much more statistics than I did!!