И это еще не сеIn the second scenario, a young woman age 51 presented to the emergency department with a severe ischemic stroke, NIHSS score of 29. Her systolic blood pressure was 165 mm Hg, serum glucose was 13.1 mmol/L, and after all her examinations, diagnostic tests, and brain imaging were performed, 2 hours had already elapsed since symptom onset. Once again, a critical treatment decision had to be made. The prevailing thought that ran through the mind of the treating physician was that the woman’s prognosis was invariably extremely poor, based on the clinical stroke severity at presentation.10,11 Additionally, the physician was reminded that a very high NIHSS score was at least a relative contraindication to administration of rt-PA. The physician recalled that the stroke severity was an independent predictor of symptomatic intracranial hemorrhage. Most patients with a symptomatic intracranial hemorrhage had experienced a severe stroke (NIHSS score >20). The physician estimated the risk of such a hemorrhage in this woman to exceed 17%.12 After presenting the pros and cons to the family, the collective decision was that rt-PA treatment was probably futile and even potentially harmful. The family grieved but felt that they understood the logic behind withholding rt-PA therapy.
In these fictional examples, the evidence-based and experience-based clinical decision-making is vulnerable to potential errors in judgment. Only some of the available evidence was used by the decision-making parties. Most of the physicians’ predictive estimates of prognosis were nonquantitative, imprecise, and even vague. Even the quoted quantitative estimates of various potential outcomes of effect and harm with or without rt-PA were hard to interpret for patients, family members, and clinicians.
Now imagine the same 2 clinical scenarios with the Stroke-TPI available for use by the treating physician. In the first case, the following patient characteristics were entered into the Stroke-TPI on a handheld computer system: age 77 years, female gender, diabetes, no prior stroke, 140 mm Hg systolic blood pressure, glucose of 15.2 mmol/L, NIHSS score of 5, and a symptom onset to treatment time of 179 minutes. The patient-specific predictions of outcome probabilities were instantly calculated and presented. As the physician had suspected, the probability of a normal or near-normal outcome without rt-PA was already quite good, at 48%, and the probability of having a catastrophic outcome was truly low, at only 13%. What was incredibly valuable was the estimate of a normal or near-normal outcome after administration of rt-PA in this woman, 72%. This quantity could easily be compared with the 48% chance of a good outcome without treatment, yielding an impressive 24% absolute risk difference. It is this risk difference that was formerly falsely perceived, by the decision-making parties, to be low or even negligible. Given this valuable, tailored, applicable, quantitative information, a different conclusion might have been reached—to treat—despite the mild stroke and late symptom onset to treatment time.
In the second case, these patient characteristics were entered: age 51 years, female gender, no diabetes or prior stroke, 165 mm Hg systolic blood pressure, serum glucose of 13.1 mmol/L, NIHSS score of 29, and 122 minutes from symptom onset to treatment time. The patient-specific predictions of outcome probabilities were calculated and presented. It was confirmed that the