Managed Care - June 2008 - (Page 22)

MEDICATION MANAGEMENT tronomically, from 0.1 percent of prescriptions in 2002 to 15.2 percent in 2006. A panel convened by the American Academy of Cardiology stated that because of the trial’s results, “the aggressively marketed drug combination should be used only as a last resort in treating patients to decrease their levels of low-density lipoprotein cholesterol (LDL-C),” according to a report in the May 21, 2008, issue of JAMA. That trial, titled ENHANCE, has led to a congressional investigation examining whether the results of the trial, which began four years ago, had been suppressed by the companies. Controversy Soon after the announcement of the trial’s results, BusinessWeek published a controversial look at whether all statins are overprescribed. “Do Cholesterol Drugs Do Any Good” in the January 28 edition stated that “except among high-risk heart patients, the benefits of statins such as Lipitor are overstated.” The article bases its conclusion — that statins are overprescribed — on a statistical methodology named “number needed to treat (NNT).” Here’s an example, as laid out in the BusinessWeek article: In a newspaper advertisement, Pfizer states that “Lipitor reduces the risk of heart attack by 36 percent. However, an asterisk is attached to that figure, leading to a statement in smaller type that reads ‘That means in a large clinical study, 3 percent of patients taking a sugar pill or placebo had a heart attack compared to 2 percent of patients taking Lipitor.’ “The numbers in that sentence mean that for every 100 people in the trial, which lasted 31⁄3 years, three people on placebos and two people on Lipitor had heart attacks,” continues BusinessWeek. “[That’s] one fewer heart attack per 100 people. So to spare one person a heart attack, 100 people had to take Lipitor for more than three years. The other 99 got no measurable benefit. Or to put it in terms of a littleknown but useful statistic, the number needed to treat for one person to benefit is 100. Compare that with, say, today’s standard antibiotic therapy to eradicate ulcer-causing H. pylori stomach bacteria. The NNT is 1.1. Give the drugs to 11 people, and 10 will be cured.” The most common methodology for describing randomized controlled trials is in terms of relative risk reductions (RRRs), the proportional reduction in rates of bad outcomes between experimental and control participants in a trial. It is calculated by dividing the absolute risk reduction by the control event rate. Absolute risk reduction (ARR) is the decrease in risk of a given activity or treatment in relation to a control activity or treatment. Many epidemiologists believe that RRR can be more useful than the absolute risk reduction in determining an appropriate treatment plan because it accounts not only for the effectiveness of a proposed treatment, but also for the relative likelihood of an incident (positive or negative) occurring in the absence of treatment. NNT, on the other hand, may best convey an idea of an intervention’s possible costeffectiveness, researchers say. But because a drug’s NNT is high, that does not mean it should not be widely prescribed, say some epidemiologists. Brian Strom, MD, is a professor of public health and preventive medicine in the biostatistics and epidemiology department at the University of Pennsylvania School of Medicine and an expert in the use of NNT. “NNT is a way to make clear the relative value of a drug,” says Strom. “It does not address whether a drug works for the reason it was intended and whether it is reasonably safe, both of which are the responsibility of the FDA based on clinical tests.” Very safe Strom says that using NNT to establish the efficacy and effectiveness of statins and other drugs is “mixing apples and oranges.” “NNT is useful in determining the cost benefit of a drug. If an NNT is high, but a drug is not expensive and is considered relatively safe, then it is still valuable,” he says. “Statins have proven themselves to be very safe and remarkably effective.” That’s true, says Brody. “But the issue is statins as a prophylaxis,” he says, “and there is increasing statistical evidence that its widespread use is simply not warranted.” MC 22 MANAGED CARE / JUNE 2008

Table of Contents Feed for the Digital Edition of Managed Care - June 2008

Managed Care - June 2008 Editor’s Memo Contents Viewpoint Letters News and Commentary Legislation & Regulation Medication Management Compensation Monitor Plans Chart Course in Rough Waters A Conversation With Barbara Starfield, MD Smoke Signals from Payers Slow Going for Clinical Decision Support Back Pain and Physical Therapy Formulary Files PlanWatch Outlook

Managed Care - June 2008

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