Wednesday, January 20, 2010

More on practice variation: Hypertension

Following up on yesterday's data about practice variation with regard to endoscopies, here is another presentation from Blue Cross Blue Shield of MA regarding treatment of hypertension.

Here's the technical explanation, provided by a colleague at BCBS:

Two medicines -- ACE-inhibitors and Arbs (Angiotensin receptor blockers) are clinically interchangeable.* ACE-inhibitors cost substantially less than Arbs. The very high rate of Arb use (23% on average) is a good example of unexplained practice variation.

We see a wide spread in cost of treatment between the lowest quartile and the top quartile. A significant component of that, 30%, is accountable to the drug cost. And over 40% of the doctors have a use of Arbs that is above the network average.

And now look below at one particular 12-doctor primary care group, where the use of Arbs ranges from 13% to 55% and where three-quarters of the group are above the network average.

I recognize that the data don't tell us everything, but they suggest areas for inquiry. Let's beware, though, of demanding more and more analysis and data before reaching the conclusion that there is no underlying problem of practice variation.

In a comment below, I quote Paul Batalden from a seminar I attended months ago:

Measurement is a reductive act. We measure an aspect of a phenomenon. We often start with one or a few measures. A "natural" reaction is to want a more representative picture of the phenomenon -- hence a "breeder reactor" for measurement.

His point, I think, is that you have to start somewhere and see what you can learn, but if you think you are ever going to satisfy all of the data needs that definitively prove something, you will never reach that point of certainty.

*There is one minor caveat: A small percent of the population has a sensitivity to ACE-inhibitors, such that they develop an annoying (though benign) cough. Most docs suggest that could be about 10 to no-more-than 15% of a patient population. So Arb would need to be used on that small group.


#1 Dinosaur said...

This is the ideal post to illustrate a huge problem I have trying to apply "outcomes research" to primary care: what, exactly, constitutes and "episode" of hypertension? It's an ongoing condition that, I guarantee, if followed long enough will inevitably result in death.

FWIW, I agree that no one should ever be started on ARBs (except perhaps patients of Asian descent, as they tend to have a higher incidence of ACEI-induced cough), but why not just come out and say that?

Anonymous said...

Now this one addresses one of my pet peeves, and that is the use of expensive drugs to treat hypertension when it usually can be treated very cheaply. For this one I would simply ask those docs, why, WHY are you using the expensive drug? (My personal opinion is: drug reps ad faddism.)
My husband, an orthopedic surgeon, treats his own hypertension and you can bet he uses the cheapest drugs available (we have no drug benefit). Works fine. Easy to monitor at home with BP measurement. End of subject.


Anonymous said...

This is interesting. One could argue that there are some generic ARBs out there now, so patients may pay the same for an ARB versus an ACE through insurance. But there aren't really any great reasons to start with an ARB.

Just out of curiosity, does this exclude ACE and ARB combination drugs? Most of the time when I saw ARBs used it was because of some free samples for an ARB/HCTZ combo or something like that. I'm assuming it probably does exclude them.

#1 Dinosaur said...

Anon 2:20: Actually no, there are no generic ARBs yet available.

And Mr. Levy, you have a spam comment above. Anything nonsensical that seems to be trying to make sense (probably written by a non-English speaker) about pain meds is usually a spammy link to "findrxonline" (inserted somewhere in the text).

D Safran said...

In answer to the question about how we classified combination drugs in the analysis, combination medicines are included in the results. Combination medicines that include ARBs are counted as use of ARBs. While combination medicines are often prescribed for improved convenience/adherence and lower patient co-payments, there are equally effective combination medications that are less costly than those including ARBs.

On the issue of generics: there are no generic ARBs available. The first, losartan (Cozaar) is scheduled to come off patent in February, 2010, with others to follow over the 3-4 years. When any brand name medication comes off patent, the patient co-payment for the generic is generally brought down quickly, but the overall cost of the medication doesn’t substantially decrease until there are multiple generic manufacturers (3-4 years).

C. Holesterol said...

Your blog was recently recommended to me, and I have to say that I love it! How did you decide to become a nurse, when you are obviously such an amazing writer?