ANAHEIM, Calif., Feb. 8 -- Clot-dissolver tissue plasminogen activator (TPA) can reduce the disability of people who survive an ischemic stroke, one caused by a clot that blocks an artery carrying blood to the brain. But given the drug's cost of over $2,000 a dose, are the benefits worth the money?
Yes, according to a new study that found using TPA not only provides a cost benefit, but saves a significant sum of money overall. "The use of TPA for eligible patients with acute ischemic stroke appears to be a 'win-win' situation, with improved patient outcomes accompanied by a net cost savings to the health care system," said Susan C. Fagan, Pharm.D., associate professor of pharmacy practice at Wayne State University College of Pharmacy in Detroit.
She reported the new findings here today at the American Heart Association's annual conference on stroke research.
In 1993, strokes cost $18 billion in direct health-care expenditures. According to the American Heart Association estimates the cost of stroke in 1997 to be $40.9 billion.
Ischemic strokes, which account for 70-80 percent of all strokes, will strike some 500,000 Americans in 1997. However, Fagan and her colleagues could not estimate how many of them might benefit from TPA because few stroke patients arrive in the emergency room within three hours after symptoms begin. TPA must be given within this time frame to be safe and effective.
Fagan and her co-workers used data gathered during the National Institute of Neurological Diseases and Stroke TPA Stroke Trial, a study of 624 acute ischemic stroke patients at nine medical centers. Half of the patients received TPA and the other half got a placebo (an inert substance).
Reported in 1995, the study found that at three months after a stroke, TPA significantly improved functional outcome but increased the risk of brain hemorrhage 10-fold (6.4 percent in the TPA group vs. 0.6 percent in the placebo group). There was no significant effect on mortality (17 percent in the drug group vs. 21 percent for placebo).
As a result of these findings, Fagan said, she and others who conducted the NINDS TPA study were frequently asked "whether it's worth it to use this expensive therapy in ischemic stroke patients."
So the investigators used data from the study, including as-yet-unpublished outcome results, and did a cost analysis using a set of reasonable assumptions. All patients, for example, were assumed to be 67 years old, the mean age of the patients in the NINDS TPA trial, and the cost of the TPA was set at $2,230, the mean price of the drug at seven Detroit-area hospitals. The yearly cost for nursing-home care was assumed to be $40,000.
The new study provides some outcome data not previously reported. The mean length of hospitalization immediately after the stroke was significantly longer for the placebo patients -- 12.4 days vs. 10.9 days for the TPA patients. "This finding was not explained by differences in the frequency of stroke subtypes between the two groups," Fagan said.
A significantly greater number of TPA patients went directly home after their initial hospitalization, rather than being discharged to a rehabilitation unit or a nursing home -- 151 (48 percent) vs. 112 (36 percent)e health care system for the 1,000 patients," Fagan and her colleagues noted. for the placebo group.
Both of these results proved major factors in the overall cost saving attributed to TPA by the study. "The treatment group did not require expensive post-hospital care as often as the placebo group," Fagan noted.
Using a computer model, she and her colleagues calculated that for every 1,000 ischemic stroke patients treated, using TPA would increase hospital costs by $2 million. However, the drug would decrease the cost of nursing home care by $4.8 million and rehabilitation costs by $2 million after the patient's initial hospitalization for stroke.
"The overall impact on both acute and long-term costs is a net decrease of almost $5 million to the health care system for the 1,000 patients," Fagan and her colleagues noted.
"In order to eliminate the overall cost savings, the length of hospital stay of the TPA group would have to exceed the placebo group by 2.6 days, or the nursing home cost per year would have to drop to near zero," Fagan said.
Given that no other effective therapy exists for ischemic stroke, the use of TPA is justified on its health benefits alone, the researchers concluded. The savings that result from using TPA offer an even greater incentive for its rapid administration to stroke patients.
"If this treatment is used properly, within three hours of onset of symptoms, it can actually save the health system money when you look at total health care costs," Fagan said.
Co-authors with Fagan were Lewis B. Morgenstern, M.D.; Antonio Petitta, R.Ph.; Richard E. Ward, M.D.; Barbara C. Tilley, Ph.D.; Steven R. Levine, M.D.; John R. Marler, M.D.; Michael D. Walker, M.D.; Joseph P. Broderick, M.D.; Thomas G. Kwiatkowski, M.D.; and Michael Frankel, M.D.