Archive for November, 2008

The Jupiter Study

Posted in Cardiology with tags on November 20, 2008 by jcm9232

Crestor, Guidelines, Rationing and Other CRP
November 13th, 2008 by DrRich

The JUPITER trial, reported this week at the American Heart Association Scientific Sessions and simultaneously published in the New England Journal of Medicine, has created quite a stir in the mass media and in the blogosphere. DrRich would like to do his bit in flaming the controversy.

On its surface the study and its results are pretty straightforward. Nearly 18,000 men and women from 26 countries who had “normal” cholesterol levels but elevated C-reactive protein (CRP) levels were randomized to receive either the statin drug Crestor, or a placebo. CRP is a non-specific marker of inflammation, and an increased CRP blood level is thought to represent inflammation within the blood vessels, and is a known risk factor for heart attack and stroke. Patients randomized to Crestor, after an average treatment period of 1.9 years, had a highly significant 44% reduction in a composite endpoint that included heart attack, stroke, the need for stenting or bypass surgery, and cardiovascular death. Both CRP and cholesterol levels were also significantly reduced in patients taking Crestor.

This study is noteworthy because it is the first large randomized trial to show that Crestor (or any statin) can markedly reduce the incidence of some very nasty cardiovascular outcomes in people who are considered to have “normal” cholesterol levels. (Notably, typical LDL cholesterol levels among primitive hunting/gathering cultures is around 50 mg/dL, instead of the 100 – 120 mg/dL we consider to be normal. These people have an extremely low incidence of cardiovascular disease, so maybe humans’ optimal cholesterol level is much lower than we now think. On the other hand, the low risk of cardiovascular disease among hunters/gatherers may instead be related to the fact that many of them are consumed by bears before they’re 30.)

So here’s what we know from the JUPITER trial: giving Crestor to patients similar to the ones enrolled in this study can be expected to significantly and substantially improve their cardiovascular outcomes, and in a relatively short period of time.

But, as with any clinical trial, this one does not answer all the questions that we would like to have answered.

This trial, for instance, does not tell us whether the beneficial outcome is specific to Crestor, or is a class effect of all statins. (DrRich believes it is very likely to be a class effect, since the statins all tend to behave similarly in virtually every other way.) This trial does not tell us whether reducing CRP levels is beneficial – it only tells us that giving Crestor to people with high CRP levels is beneficial. (As Dr. Centor points out, it is time to begin thinking of statins as plaque-stabilizing drugs instead of cholesterol-lowering drugs; their benefit may not rely on lowering either CRP or cholesterol.) It does not tell us whether using CRP as a screening tool is actually helpful. (Only patients whose CRP was elevated were enrolled in this study. Similar patients – that is, patients who tend to be overweight and have a fairly high incidence of metabolic syndrome and a relatively high incidence of smoking – but with normal CRP levels, might have had the same outcome.) And this trial does not tell us the risks of lifelong Crestor therapy. (DrRich notes, however, that statins have been in widespread clinical use for nearly 20 years, and seem unlikely to hold very many surprises at this point.)

So there’s a lot we still don’t know, and much of what we don’t know would be important to any doctor counseling a patient who wants to reduce their risk of cardiovascular disease.

But still, there should be no controversy here. If medicine were practiced the way it ought to be – where the doctor takes the available evidence, as imperfect as it always is, and applies it to each of her individual patients – then the JUPITER trial would present no special problems. After all, doctors never have all the answers when they help patients make decisions. So, in this case the doctor would discuss the pros and cons of statin therapy – the risks, the potential benefits, and all the quite important unknowns – and place the decision in the perspective of what might be gained if the patient instead took pains to control their weight, exercise, diet, smoking, etc. At the end of the day, some patients would insist on avoiding drug therapy at all costs; others would insist on Crestor and nothing else; yet others would choose to try a much cheaper generic statin; and some would even opt for a trial of lifestyle changes before deciding on statin therapy. In other words, there is a range of reasonable options given the limitations of our knowledge, as there often is in clinical medicine. As time goes by, more scientific evidence is often brought to bear and clinical decisions (hopefully) become more and more effective. But whatever the state of the evidence, doctors and patients can generally get by without violating too severely any ethical or medical precepts that would cause objective and neutral observers to complain very much.

But we don’t practice medicine the way it ought to be. We practice it according to guidelines.

And this makes the stakes very high when it comes to a clinical trial like JUPITER. For guidelines do not generally permit a range of actions tailored to fit individual patients – they generally present a binary answer. In this case, the binary answer yields either no change in clinical practice (and no change in spending), or a change in clinical practice (and an increase in spending, on Crestor, amounting to several billion dollars a year).

So as one might predict, a controversy has broken out.

On one hand, many point out that JUPITER is an important clinical trial which has demonstrated a vital clinical benefit (prevention of heart attack, stroke and death) with a high degree of statistical significance, which meets the high standards demanded by evidence-based medicine, and which therefore obviously demands a change in the clinical guidelines. But on the other hand, many others insist that the JUPITER trial simply does not demonstrate enough of a benefit with Crestor to justify changing the guidelines.

DrRich’s position – that the results of the JUPITER trial are striking and important but incomplete, and ought to change the conversation between, but not dictate the actions of, doctors and patients – does not obtain in the modern era.

So, unable to side with either party, DrRich observes with great interest the debate between those who want to change the guidelines, and those who believe that changing the guidelines would be the greatest of travesties.

Those who want to change the guidelines have, in their favor, the virtue of consistency. For, if one insists that every action by physicians must be supported by evidence-based medicine, then one is pretty much obligated to fully embrace clinical trials like this one that give clear-cut and statistically significant results. Unfortunately, the evidence-based strict-constructionists have painted themselves into a corner when it comes to JUPITER. They will not be able to say, for instance, “Statins are pretty much alike, so we’ll make the guidelines say ’statins’ instead of ‘Crestor.’” For JUPITER did not study “statins,” it studied only Crestor, the most expensive statin on the planet. Expanding the results to all statins (despite a large body of experience that suggests this would be just fine) does violence to the whole concept of evidence-based medicine. It’s just not possible. The strict constructionists have therefore boxed themselves in to advocating a new, multi-billion dollar annual expenditure.

It is even more amusing to observe those who do not want to change the guidelines.

These people fall into two general camps. First, and easier to dismiss, are those who believe that drug companies are the embodiment of evil, and that any clinical trial sponsored by a drug company must be dismissed out of hand. There is furthermore a subset of this group who believe that statins, in particular, are the devil’s work, and represent some sort of effort on the part of the pharmaceutical companies (all of which seem to market a statin of one variety or another) to enslave every American. These people, one can only surmise, would object to statins even if they were proven to cure heart disease, cancer, baldness, obesity AND to produce fine and durable erections upon demand.

DrRich simply points out that the advancement of clinically useful medical science – in America and in the world – is almost entirely dependent on drug companies and other corporate dens of iniquity. That companies must pay for our medical research is the system we’ve invented. Furthermore, our total capitulation to the dictates of evidence-based medicine means that companies must fund large, expensive clinical trials before they are allowed to sell a new product, or create a new indication for an old product. This evidence-based paradigm is inherently a double-edged sword. Sure, it creates a huge barrier to the development and adoption of expensive new therapies (which is the covert rationing dividend of evidence-based medicine), but it also creates opportunities, for companies who manage to successfully complete such trials, to create iron-clad indications for their products. For, once a product has been “proven” in a randomized clinical trial, there is no easy way to legitimately keep that product out of the guidelines and off the shelves. The makers of Crestor have simply figured out the rules. One can whip up anti-corporate emotions by criticizing AstraZeneca for playing the game well, but the fact that the sponsor stands to gain does not negate in any way the results of a well-designed study.

That the anti-pharmaceutical and anti-statin crowds vociferously object to the results of the JUPITER trial is, of course, entirely expected and cheerfully acknowledged. DrRich will merely observe that their position is one of default. It is not dependent on the scientific merit of JUPITER (or any company-sponsored study), and thus it adds no useful information to the debate. We can only note their objections and move on.

The second group of people who object to changing the guidelines are less dogmatic and more open to reason, and indeed (and very interestingly so) claim to be proponents of evidence-based medicine, and thus claim to be willing to follow the data to where it will lead. It seems pretty clear (to DrRich, anyway), that the chief concern of these individuals is cost. That is, this group feels strongly that the implications of the JUPITER trial are simply too costly to follow to their logical conclusion. This, indeed, is a very reasonable position to take.

Unfortunately, the only legitimate way to turn aside the results of a costly but statistically definitive, evidence-based study is by rationing healthcare. (To ration, remember, is to withhold at least some useful medical services from at least some people who would be likely to benefit from those services.) But we can’t do that, because, well, it would be rationing. Because members of this second group are unable to invoke the “r” word, they are therefore forced to find other “reasons” for keeping the guidelines unchanged. This unfortunate situation leaves them little choice but to discover ways in which to impugn the legitimacy of the JUPITER trial.

In short, they find themselves forced to engage in statistical legerdemain in order to diminish the significance of the JUPITER trial. From what DrRich has seen, most of the statistics that have been ginned up to this end have not come directly from the JUPITER trial itself, but instead from an editorial accompanying this study, written by Dr. Mark A. Hlatky.

Most of Dr. Hlatky’s editorial is measured and reasonable. But he has thrown in a key summary sentence that has been greedily grasped by the antialterguidelinetarians, to wit: “The proportion of participants with hard cardiac events in JUPITER was reduced from 1.8% (157 of 8901 subjects) in the placebo group to 0.9% (83 of the 8901 subjects) in the rosuvastatin group; thus, 120 participants were treated for 1.9 years to prevent one event.”

This statement, at least taken at its face value as a stand-alone analysis, is statistically naive and wrong. DrRich will not make anyone wade through the reasons why, because he realizes that one or two of his readers might not enjoy statistical arguments. (Instead he will provide those reasons in this footnote.*) Suffice to say here that Hlatky’s summary statement apparently ignores the appropriately analyzed data which is clearly presented in the JUPITER paper itself, and which documents that the clinical benefit of Crestor was substantially more impressive than this widely-quoted summary statement by Hlatky suggests.

As illegitimate as this summary statement may be, let us accept it for a moment just for the sake of discussion, since that’s the data the antialterguidelinetarians have latched on to. Taking these numbers, the “antis” make the following argument: While the relative reduction in “hard cardiac events” is 50% (1.8 to 0.9), the absolute reduction is only 0.9%, which, anyone would agree, is a pretty small number. So, they conclude, the actual benefit imparted by Crestor is actually quite small.

That’s a very interesting argument. Let’s look at it in a couple of ways.

So we’ve got a population of patients whose risk of heart attack, stroke, bypass surgery/stenting, or death is about 2% at about 2 years, and by giving them a pill we can reduce that risk to about 1%, and we’re arguing that the absolute drop of 1% is not very much to crow about. Well, OK. But what if we found a pill that reduced their risk to zero at 2 years? That is, it completely wiped out the risk of cardiovascular catastrophes. Would that be a good thing? Or would we say, “It’s just a 2% drop, really not much greater than the 1% drop we had with Crestor, so it’s no big deal?” DrRich thinks not. DrRich supposes we would think it’s a very big deal.

When you’re starting at a 2% risk, then any drop in risk is going to be an “absolutely” small number. And if we’re not going to pursue improvements in outcome of such a small magnitude, then why the heck are we worrying about preventative medicine in the first place? Once you get past the big things (drain the swamps, don’t drink the water downhill from the outhouse, etc.) then all preventative medicine tends to consist of small, incremental improvements in outcome. Popular pronouncements to the contrary notwithstanding, preventative medicine is largely the art of spending a lot of money for this kind of incremental improvement. If we decide we shouldn’t do this anymore, then DrRich would find it unfortunate but understandable. But it hardly seems reasonable to arbitrarily focus on this one, particular improvement in preventative cardiology, and (within a healthcare system that insists it is not rationing care) pronounce that this is the one we’re not paying for.

Another way of looking at this “the benefit is too small” argument is by considering that 7.4 million Americans fit the entrance criteria for JUPITER. By giving all these people a statin, we would be preventing about 66,600 major cardiovascular events over a 2 year period. If you’re going to say that 1% is a small number, DrRich will counter that 66,600 is a big number. So do statins offer a substantial benefit or not? It depends on whether you choose to focus arbitrarily on the 1% or the 66,600.

(DrRich understands that many of his readers are not focusing at this moment on the 66,600 cardiovascular catastrophes that could be prevented, but on the 7.4 million people who will be taking a drug that costs $120 per month. But we’re not talking about cost yet, we’re only talking about whether the drug does some good. If we decide it does, then we’ll need to link that “good” to a procedure that measures whether the “good” is worth the money we would need to spend to achieve it. The “antis” try to avoid talking about cost – since that would admit they’re rationing – by insisting that there’s just not enough “good” to bother. DrRich is simply pointing out that such an argument – that preventing 66,600 very bad outcomes is not enough to bother with – is on its face absurd.)

Another argument invoked by the antialterguidelinetarians is based on the “number needed to treat” (NNT) analysis. Again they rely on Hlatky’s unfortunate summary of the data: “120 participants were treated for 1.9 years to prevent one event.” This number – which the “antis” insist is just too high – is misleading for the reasons outlined in the footnote.* The real NNT, based on more legitimate statistical analysis, is plainly laid out in the JUPITER paper itself. It turns out that the longer patients in this trial were treated with Crestor, the lower the NNT became. So: At 2 years, the NNT was 95; at 4 years, it was 31; and at 5 years, it was projected to be only 25. Whether you think it is reasonable to treat 25 people with a pill for 5 years to prevent one of them from having a heart attack, stroke, or death is, DrRich supposes, a matter of opinion. But based on NNT analyses for many widely-accepted therapies in medicine today, it looks pretty good.

All these arguments, of course, are merely distractions. The fact is that JUPITER showed a pretty striking reduction in nasty cardiovascular events, and the only real reason there’s any controversy is because of the cost of Crestor.

That cost is what makes us want to withhold Crestor, even though it is imparting at least some (and, DrRich, argues, quite a bit of) clinical benefit. In other words, the high cost makes us want to ration Crestor. The fact that we can only ration covertly, instead of openly, is what makes us want to bastardize the science and do a Kabuki dance with the statistics.

If we were rationing healthcare openly, then we could do an objective, full-bore cost-benefit analysis on the use of Crestor in JUPITER patients, using legitimate and not ginned-up statistical analysis, and taking into account not only the cost of the drug, but also the cost that would be incurred by failing to stop preventable heart attacks, strokes, etc., and then determining where the overall cost-benefit result fell within our coverage criteria. If it met the criteria we would cover it, if not, not. This decision would not be arbitrary. It would be a fully transparent process, so that if AstraZeneca did not like the results, they would try diligently to find a way to reduce the cost of Crestor (DrRich thinks they would succeed) to a value that would be compatible with their staying in business. (And for the first time, the price of medical products would be determined by a Laffer-like curve, where a price that was too high – like taxes that are too high – would reduce revenue, instead of increase revenue. Companies, being fairly rational, would ratchet their prices down to the optimal price point.)

But since we insist on doing our rationing covertly, DrRich is sorry to say that we’re destined to keep making spurious arguments, and using dumbed down statistical analysis to back them up. The JUPITER trial, while it is imperfect and while it does not answer every question, really is pretty straightforward. That we get so wrapped around the axle trying to fold such clinical trials into our covert rationing paradigm is simply another demonstration of Corollary Four of the Grand Unification Theory of Healthcare: Covert rationing corrupts everything it touches.

*In a long-term clinical study in which the endpoints are events that can occur at any time (such as heart attack, stroke or death), then the probability that an enrolled patient will reach an endpoint in the trial increases the longer he/she has been enrolled in the trial. But in virtually all clinical trials, the length of time different people are enrolled varies greatly. This is because it often takes years to enroll people in clinical trials, so that when the trial ends, some will have been in the trial for many years, others for only a little while. This means that the risk exposure of each research subject is different, and is proportional to the total time they were enrolled. Not uncommonly, the enrollment process is not smooth – there are periods of more rapid enrollment, and periods of slower enrollment – so if all you do is average the enrollment time (as was done here – 1.9 years) you are likely to get skewed results. So it is simply not statistically legitimate to do so.

There is a legitimate way of analysing such longitudinal outcome statistics, and it’s called the Kaplan-Meier method. And indeed, the authors of the JUPITER trial presented in their paper a complete Kaplan-Meier analysis of their data (see Figure 1), and the results look quite a bit different from Hlatky’s summary statement. The Kaplan-Meier analysis reveals that the risk of heart attack, stroke, and death all increase steadily through at least 4 years (5 years was the longest time anyone was enrolled in this study), so that at 4 years, the risk of reaching one of the “cardiovascular event” endpoints was about 8% (not 1.8%). Further, the Kaplan-Meier analysis shows that the protection imparted by Crestor persists through at least 4 years, and that indeed the magnitude of protection (i.e., the difference in outcomes between the treated group and the placebo group) increases for that entire duration. So, at 4 years, the placebo group had roughly an 8% event rate, compared to roughly a 3% event rate for the Crestor group – an absolute difference of about 5% (not 0.9%). This is a far greater benefit than is suggested by Hlatky’s shorthand summary.

JUPITER Crestor CRP clinical guidelines rationing healthcare covert rationing
Posted in General Rationing Issues, Cardiology Topics, Guidelines, Abuse of, Evil Drug Companies

Acute Lumbar Disk Pain

Posted in Ortho with tags on November 20, 2008 by jcm9232

http://www.aafp.org/afp/20081001/835.html

Syncope Evaluation and Management

Posted in Cardiology with tags on November 20, 2008 by jcm9232

http://www.mayoclinicproceedings.com/inside.asp?AID=4827&UID=

Evaluation of Dipstick Hematuria

Posted in Uncategorized with tags on November 20, 2008 by jcm9232

How to evaluate ‘dipstick hematuria’: What to do before you refer
PRAVIN KUMAR RAO, MD
Glickman Urological and Kidney Institute, Cleveland Clinic
J. STEPHEN JONES, MD*
+Author Affiliations

Vice Chairman, Glickman Urological and Kidney Institute, Cleveland Clinic; Associate Professor of Surgery, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University
ADDRESS: J. Stephen Jones, MD, Glickman Urological and Kidney Institute, A100, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195; e-mail joness7@ccf.org.
Abstract

Although major health organizations do not support screening for hematuria by dipstick testing, millions of patients without symptoms are tested yearly. Since urinary dipstick tests for hematuria have a high false-positive rate, patients with positive dipstick results require microscopic urinalysis before the diagnosis of hematuria can be made. Primary care physicians can help protect patients from the anxiety, costs, and risks of an unnecessary urologic workup by adhering to the principles of early hematuria management.

KEY POINTS
Dipstick tests by themselves do not confirm that hematuria is present; thus, “dipstick hematuria” is a potential misnomer. Patients without symptoms who have a positive dipstick test and negative microscopic urinalysis are better described as having dipstick pseudohematuria, a clinically insignificant finding.

Significant hematuria is defined as three or more red blood cells per high-power field in a properly collected and centrifuged urine specimen; this is the definition that should dictate which patients require further urologic evaluation.

Since the evaluation for hematuria usually includes cystoscopy and imaging studies, it is crucial to confirm that hematuria is truly present before initiating an invasive and costly evaluation.

FULL ARTICLE http://www.ccjm.org/content/75/3/227.full