Like medical errors and hospital-acquired infections-both so-called adverse events that strike fear in the hearts of hospital administrators and clinicians alike-just being in a hospital puts patients at substantial risk for deep vein thrombosis. But unlike medical errors and hospital-acquired infections, DVT, as it is commonly called, can be avoided more than half the time with some proven preventive treatments.
Victor Tapson, an associate professor of medicine at Duke University Medical Center in Durham, N.C., and the co-lead investigator of a national study of patients at risk for DVT, was asked what was the most cutting-edge advancement in preventive treatment for this life-threatening condition.
"At the present time, awareness is crucial," Tapson says. "March was DVT Awareness Month. That was a step in the right direction."
Medical advances aren't always rocket science.
The condition, caused by the formation of a blood clot in the deep leg vein, can lead to permanent damage to the leg, known as post-thrombotic syndrome, or if the clot travels, to a deadly pulmonary embolism in the lung, blocking the flow of blood. The blood clots form as a result of illness, injury or inactivity, according to the Society of Interventional Radiology, and the condition can be exacerbated by dehydration. Hospitalized patients, who in this day and age of intensive hospital care are frequently immobile, are by definition at risk.
A common killer
In the U.S., 600,000 new cases of DVT are diagnosed each year, and one in every 100 people who develop it dies, according to the radiological society. It's what killed NBC newscaster David Bloom after hours of driving through the hot Iraqi desert, crunched up in an army vehicle. Pulmonary embolisms kill more than 100,000 people in the U.S. each year-more than breast cancer, traffic fatalities and AIDS combined, Tapson says.
As part of its healthcare cost and utilization project, the federal Agency for Healthcare Research and Quality estimates that 72,700 patients developed DVT and pulmonary embolism in U.S. hospitals in 2000. Meanwhile, as part of a study on excess lengths of stay, charges and mortality attributable to medical injuries, researchers from the AHRQ calculated that DVT resulted in 5.36 extra days and $21,709 in extra charges per case as well as 6.56% more deaths in 2000. (The study was published in the October 2003 issue of the Journal of the American Medical Association.) Based on a cost-to-charge ratio of 0.55, those charges are equal to about $11,940 in excess costs, says Roxanne Andrews, senior health services researcher for the healthcare cost and utilization project at the AHRQ. Multiplied by the 72,700 cases, DVT and pulmonary embolism collectively cost U.S. hospitals an extra $868 million in 2000, Andrews estimates.
Tapson says he believes preventive measures result in self-evident cost savings. "It doesn't take too many blood clots that you haven't prevented to pay for prophylactic treatment," he says. Estimates are that post-thrombotic syndrome costs $200 million annually in the U.S., he says.
The study by researchers at Duke and at Brigham and Women's Hospital in Boston encompassed 5,000 patients with DVT, half of whom were hospitalized. Of those approximately 2,500 inpatients, only 42% received prophylactic therapy before their diagnosis-even if they had had previous episodes of DVT, Tapson says. Perhaps more alarming, he says, doctors often failed to prescribe the most proven effective drugs for treating the disorder in patients with DVT, opting for older treatment methods instead.
The study was funded by Aventis, a pharmaceutical company that manufactures low molecular weight heparin, or LMWH, a drug that can both treat and prevent DVT. Tapson is a paid consultant for Aventis.
"Clearly, there is a disconnect between evidence and execution as it relates to DVT prevention and treatment," Tapson says. He believes every hospitalized patient should be considered for preventive measures. "At the very least, everyone coming in the door should be screened," he says.
No known studies have been undertaken to quantify the cost of DVT to the healthcare system vs. the potential cost of preventing it. For reasons that are not all that clear, the incidence of DVT has increased in the past 10 years, by perhaps twice as much, says George Martin, a physician and senior director of clinical consulting for hospital cooperative VHA. Risk of DVT depends on the age and medical history of the patient. Patients who are immobile-post-surgical patients most often fall in this category-are at higher risk as well. In general, 25% of all post-surgical patients are at risk of getting DVT, and if they get it, as many as 5% of them are at risk of dying from it, he says.
There are several preventive treatment options for DVT in moderate- to high-risk patients, Martin says. Drug therapy options include the blood-thinner heparin, which costs pennies per dose and can be administered by needle three times a day. Alternatively, physicians can opt for LMWH, a subset of heparin, which can be administered by needle just once a day, has fewer side effects than heparin but costs about $18 per dose. Mechanical preventive treatments offer three choices: compression devices to the knee, compression devices to the thigh and simply getting the patient up and out of bed, Martin says. The last alternative, of course, is easier said than done, he adds.
Compression devices, which are single-use only and can cost as much as $200 per pair for the knee-high version and twice as much for thigh-highs, seem to benefit patients only when used in conjunction with drug therapy, Martin says. Drug therapy alone can reduce the risk by as much as 60%, and when a compression device is added, the risk is further reduced another 3% to 5%, he says.
Apart from the acquisition costs of the drugs and mechanical devices, there are other administrative costs to consider, Martin says. Standard heparin is a complicated drug with side effects, and it carries a lot of associated laboratory costs. Martin says he can understand why administrators might prefer using pure heparin because of its lower acquisition costs while physicians would prefer the LMWH because nurses like its easy administration. When nurses are happy, doctors are happy, he says.
"The whole other cost is not doing anything," Martin adds. "I think there are probably still a fair amount of places that are not choosing to stratify (patients) and provide prophylactic treatment to moderate- and high-risk patients-probably more by habit than by choice."
Weighing in on the heparin vs. LMWH debate, consulting firm Aon has been analyzing the costs of the two as part of a clinical effectiveness initiative. The overall goal of the initiative is to produce the kind of evidence both clinicians and administrators need to make medical decisions that are good for both the patient and the hospital. The results in this first program focused on DVT-also underwritten by an unrestricted grant from Aventis-have been counterintuitive to what hospital financial people might think. To date the 15 hospitals that are participating at this time have collectively saved $8.4 million a year-an average $536 per case-by prescribing LMWH instead of heparin, says Randy Vogenberg, senior vice president of Aon's consulting life sciences practice. Vogenberg adds that most hospitals are doing nothing to prevent DVT. "That's a problem," Vogenberg says. "If you do nothing, it is costing more money than you would think."
Tapson guesses there are a number of reasons why DVT risk is being ignored in hospitals. Doctors focus so hard on taking care of the diagnosis at hand, they "tend to forget about something that hasn't really happened yet," he says. Others perhaps worry about the side effects of the drugs, primarily bleeding, but he says the bleeding rates with LMWH are quite low. Also, it's a condition that crosses all service lines in a hospital-from cardiology to oncology to orthopedics.
"It's kind of everybody's disease and therefore not anyone's disease," Tapson says.
Even if DVT prevention hasn't yet hit the radar screens of many hospitals, organizations that measure quality and performance are starting to take notice. Evaluation of all hospital patients for risk of DVT upon admission is one of 30 safe-practice standards for all healthcare organizations that have been endorsed by the National Quality Forum. The standard also stipulates that organizations should "utilize clinically appropriate methods to prevent" DVT.
Though the Joint Commission on Accreditation of Healthcare Organizations has no standards addressing the issue, DVT is under consideration for a measure in the disease-specific care certification program for stroke, says Charlene Hill, a JCAHO spokeswoman. The draft measure stipulates that stroke patients who are nonambulatory should start receiving heparin, LMWH or compression stockings by the end of the second day of their hospital stay. Hill also notes the JCAHO may not require hospitals to screen patients for DVT risk, but if a hospitalized patient were to die from a pulmonary embolism, the JCAHO would consider it a sentinel event.
To get a handle on what hospitals are doing about DVT, Premier hospital alliance looked at practices at the 30 top-volume hospitals participating in its Perspective comparative database, a fee-for-service repository that collects monthly clinical and financial data from hospitals. The study examined preventive treatments, including drugs, compression devices and combinations of both, and concluded that hospitals were all over the map in what they employed, says Hunter Kome, a Premier spokesman.
Preventing DVT doesn't take much effort, as Martin illustrates in a story he tells of an unidentified South Carolina hospital he consulted with several years ago. In redesigning orthopedic care at the hospital, a too-high occurrence of urinary tract infections was noted among postoperative hip- and knee-implant patients-the patients at the highest risk for DVT, he says.
The decision was made to remove catheters within hours of surgery rather than the two or three days that they had been left in before the redesign. As a result, patients were out of bed and walking with assistance to the bathroom more quickly, which lowered the urinary tract infection rate dramatically. The rate had been more than 17% before the redesign and plummeted to less than 5%. But also, there was an unexpected consequence: The DVT rate, which had been running at 40% among that patient population, declined to 15%-just by getting patients out of bed.
"It was a great win at the time, and in retrospect, we should have expected it," Martin says.