Do potential patients prefer tissue plasminogen activator (TPA) over streptokinase (SK)? An evaluation of the risks and benefits of TPA from the patient's perspective

Background: In patients with acute myocardial infarction, TPA (compared to SK), has been shown to reduce the 30-day mortality rate at the expense of a n increased rate of stroke. The assumption in the literature is that were i t not for cast issues, all patients presenting with a myocardial infarction would choose TPA. Our hypothesis is that, for many informed individuals, r egardless of cost, the increased risk of stroke may deter them from selecti ng TPA over SK. Objective: To assess which thrombolytic drug informed patie nts would prefer and to explore the clinical and economic implications of s uch preferences. Design: Prospective survey. Setting: Tertiary care hospita l, patients: 120 hospitalized patients with cardiac disease who would be "a t risk" for a myocardial infarction. Interventions: Face-to-face interviews utilizing a decision instrument. Measurements: To minimize bias in solicit ing patients' preferences and to standardize the presentation of informatio n we developed a decision instrument which portrays a case scenario of a my ocardial infarction, describes treatment outcomes (survival and stroke rate ), and displays the likelihood of these outcomes with SK and TPA using thre e scenarios: a base stroke risk (all patients data), a lower stroke risk (< 75 years old data), a higher stroke risk (>75 years old data). Outcome data were derived from the published literature (GUSTO study). Results: When pr esented the overall results of the GUSTO study, 60/120 (50%) expressed a pr eference for SK. When presented the outcome data for the subgroups of patie nts <75 years old (lower stroke rate), 37/120 (31%) preferred SK. When pres ented the subgroup data for patients >75 years old (higher stroke risk), 67 /120 (56%) preferred SK. Conclusions: Regardless of the scenario that indiv iduals were presented with, a substantial proportion of individuals (31-56% ) who could potentially require thrombolytic therapy chose SK over TPA. Thi s study should be repeated in other settings to establish the generalizabil ity of our results. Assuming that these results will be consistent, conside ring the patient's perspective has significant implications on clinical dec ision making as well as from an economic perspective: (C) 2000 Elsevier Sci ence Inc. All rights reserved.