PHILADELPHIA—Administering t-PA to patients with mild stroke could save costs or be highly cost-effective, according to economic analyses presented at the 66th Annual Meeting of the American Academy of Neurology.
The cost-effectiveness of t-PA depends on the therapy’s ability to increase the proportion of nondisabled patients by 2%. The efficacy of t-PA in patients with mild stroke remains uncertain, however. “Controlled clinical trials are necessary to definitively establish the clinical and economic value of t-PA in this patient population,” said Gregory F. Guzauskas, PhD, from the Center for Genomics and Healthcare Equality at the University of Washington, Seattle.
Dr. Guzauskas and colleagues developed a decision analytic model to simulate the outcomes of patients with mild stroke who were treated with t-PA versus patients who were untreated. The researchers derived estimates of t-PA’s effectiveness in patients with mild stroke from a subset of participants in the Third International Stroke Trial (IST-3) and from results of the Acute Stroke Accurate Prediction (ASAP) study. IST-3 was a randomized controlled trial comparing patients who received t-PA with untreated patients. ASAP was a prospective cohort of consecutive patients with mild deficits (NIH Stroke Scale score of 5 or less) presenting within 24 hours of stroke onset and without baseline disability.
Nondisabled patients were defined as having a modified Rankin scale score of 0 to 1 at 90 days. In the subset of patients in IST-3 with mild stroke, 9% more patients who received t-PA within three hours were nondisabled at study completion, compared with untreated patients. The researchers applied this 9% difference in outcome to the ASAP observational arm to derive the t-PA arm of their analysis. Dr. Guzauskas and colleagues assumed that the treatment arms would have equal mortality rates and that the distribution of mRS outcomes would be the same as in the IST-3 subset.
The researchers estimated that treatment with t-PA would result in an increase of 0.35 quality-adjusted life years per patient and a cost savings of $20,700, compared with remaining untreated. The factors that most influenced this result were the effectiveness of t-PA, health care costs for disabled patients, and quality of life for nondisabled patients. Nondisabled patients have greater quality of life and lower annual health care costs than disabled patients. Probabilistic sensitivity analyses indicated that t-PA is 88% likely to be cost-effective.
—Erik Greb