Published in the December 2004 issue of Today’s Hospitalist
Low-molecular-weight heparin costs more than unfractionated heparin, but can it be safer “and ultimately less expensive “than more traditional anticoagulants in the acute care setting? Recent research uncovered data that may not only help answer that question, but provide some insight into how physicians can better prescribe drugs known for troublesome side effects.
To get a handle on how different types of anticoagulants affect both costs and adverse events, researchers examined prescribing patterns before and after hospitals implemented guidelines to help physicians choose the most appropriate anticoagulant for their inpatients. The bottom line? After implementing the guidelines, hospitals saw their overall costs for treating these patients drop.
While that result was significant, it was only the beginning. Researchers found that when physicians followed the guidelines, which are based on well-established evidence about how to prescribe anticoagulants, there were other major changes. Physicians changed not only the types of anticoagulants they prescribed, but the types of patients to whom they gave the drugs.
Concerns about risk, costs
The project began when a group of pharmacists was asked to examine how anticoagulation therapy guidelines could help reduce costs and adverse events like bleeding for initial use of anticoagulants in the acute care setting. Mercy Resource Management Inc., a group purchasing organization that at the time included about 100 Catholic hospitals, was interested in the topic for several reasons, according to the study’s lead author, Glen T. Schumock, PharmD, MBA, director of the Center for Pharmacoeconomic Research at the College of Pharmacy at the University of Illinois in Chicago.
One pressing concern, he explains, was the number of adverse reactions associated with anticoagulants. “You have a number of possible adverse effects,” Dr. Schumock says, “including bleeding and recurrent thromboembolism, especially with warfarin and heparin.”
Cost was another consideration. At the time the study began in the late 1990s, low-molecular-weight heparin accounted for a huge portion of the purchasing group’s pharmacy budget.
Finally, researchers felt that there was some confusion among physicians about exactly which type of anticoagulant to prescribe for individual patients. Because each of the three low-molecular-weight heparins then on the market had been approved for very specific indications, researchers worried there was confusion among physicians about exactly when to prescribe each. Further complicating matters, Dr. Schumock explains, was the fact that each of the low-molecular-weight heparins required different dosing regimens.
To help sort through all of these concerns, the purchasing group asked the researchers to answer a basic question: Are low-molecular-weight heparins worth their additional expense when compared to unfractionated heparin, particularly when you consider the costs of monitoring patients and treating adverse effects?
Researchers started the process by surveying the community hospitals that were part of the purchasing group. While most of the hospitals said they didn’t have any prescribing guidelines for anticoagulants, most said they would implement the guidelines if the purchasing group shouldered the work of creating them.
Dr. Schumock says that at the time, there was relatively little in the way of guidelines for physicians. While groups like the American College of Chest Physicians and the American Heart Association had released guidelines for the use of anticoagulants for particular patient populations, he explains, the guidelines did not provide specific recommendations on dose or length of therapy.
Because prescribing anticoagulants in the inpatient setting requires a fairly complex decision-making process, researchers decided to give physicians a fair amount of information in the guidelines. The guidelines, for example, compare the overall costs of prescribing different drugs on a scale of one to three. With intravenous heparin, the guidelines factor in the costs of the pump to administer the drug and the costs of monitoring the patient.
The guidelines also compared the convenience of different therapies on a scale of one to three. A once-a-day drug, for example, received a higher score in terms of convenience than a therapy that must be taken more often.
Same indication, different patients
While the guidelines were sent to all of the 100 or so hospitals that belonged to the purchasing group, researchers examined their impact on a much smaller group of 15 facilities.
Researchers found that more anticoagulants were prescribed appropriately after the new guidelines were implemented (86.9 percent) than before (59.8 percent). That told them that physicians at the 15 hospitals that had modified their prescribing patterns to follow the guidelines’ advice.
Dr. Schumock says that before the guidelines were implemented, researchers had identified several common problems. Physicians often didn’t prescribe a high enough dose of a certain anticoagulant, for example, or they weren’t prescribing the correct number of doses in a given day (they were prescribing Q8 instead of Q12).
But the guidelines clearly influenced more than just physicians’ choice of dosages. Dr. Schumock says that in hospitals that took part in the study, researchers found that physicians began prescribing more low-molecular-weight heparin than unfractionated heparin.
While the guidelines called for prophylaxis before general surgery, for example, they urge physicians to avoid using heparin in the highest risk patients. They instead suggest prescribing low molecular-weight heparins to these patients.
After the guidelines had been implemented, more patients received enoxaparin or dalteparin subcutaneously every 24 hours. Fewer patients received heparin subcutaneously every 12 hours. Dr. Schumock says this change occurred primarily among patients being treated prophylactically after surgery or during an acute illness.
Before the guidelines were implemented, anticoagulation was most commonly used for prophylaxis of deep vein thrombosis/ pulmonary embolism and treatment of acute coronary syndrome. While that remained the No. 1 indication for anticoagulation after the guidelines were implemented, researchers found that physicians had started giving anticoagulants to a slightly different group of patients.
After the guidelines were implemented, physicians were writing more orders for prophylaxis in medically ill patients and individuals who had suffered trauma. Fewer orders, by comparison, were written for prophylaxis in patients about to undergo general surgery.
Adverse events and costs
Those changes had a clear effect on both adverse events and overall costs. Before the guidelines, hospitals in the study had documented 22 adverse events such as bleeding or recurrent thromboembolism. After the guidelines were implemented, that number dropped to 14. (See “Inpatient anticoagulant guidelines and the effects on adverse events,” below for more information.)
Overall, Dr. Schumock says, the risk ratio of hospitals in the study dropped to 0.64. While that number was not statistically significant, he thinks it depicts an encouraging trend.
“You can say there was a definite trend toward fewer adverse events,” Dr. Schumock acknowledges, “but our population was small. If we had treated more patients, we would have clearly seen statistically significant results.”
Dr. Schumock says that in large part because of that drop in adverse events, hospitals participating in the study saw their costs of caring for patients on anticoagulants drop. “When you look at the costs of adverse events compared to the costs of the drugs,” he explains, “the drug costs are rather insignificant.”
The research included the costs of treating an adverse event like bleeding or recurrent thromboembolism and factored those costs into the equation. Overall hospital costs came in at $194,965 before the guidelines. Afterwards, hospitals spent $145,119, for a savings of just under $50,000 for a group of 264 patients.
While the numbers may be impressive, the study questions how it will be received by hospitals. The paper notes that because hospital budgets are “compartmentalized,” pharmacy directors may feel pressure to hold down the budget for drugs “even if that means that overall hospital costs are higher.
While that may be the case, the purchasing group has decided that the model was a success, and it has begun applying it to other drugs. Researchers have already completed a project examining the use of IV proton pump inhibitors, and another team is completing research examining a new treatment for acute decompensated heart failure in the ER.