Measuring Outcomes as a Function of Baseline Severity of Ischemic Stroke

Abstract

Background: The spectrum of neurological impairments following acute ischemic stroke is broad. The initial stroke severity predicts responses to treatment and outcomes after ischemic stroke. While clinical trials are using baseline severity as an enrollment criterion or a stratified variable, adjustment of outcome measures as a function of initial impairments has not been done. Methods: We developed a responder analysis that defines favorable outcomes at 90 days as influenced by the baseline National Institutes of Health Stroke Scale (NIHSS). Favorable outcome was defined as a modified Rankin Scale (mRS) score of 0 if the baseline NIHSS score was <8, mRS score of 0–1 if the NIHSS score was 8–14, and mRS score of 0–2 if the NIHSS score was >14. The concept stemmed from the data of two European rtPA trials. The analysis is a predefined secondary endpoint in a trial testing abciximab. We also used the analysis to reexamine the Trial of Org 10172 in Acute Stroke Treatment data. Results: The responder analysis did not change the overall results of any of the 3 previous trials, but it did give information about differences in responses among subgroups of patients. Evidence about the potential utility of tPA for treatment of patients with mild stroke appeared from the analysis of the second European trial of rtPA. The analysis also provided a hint of efficacy of abciximab. Conclusions: The responder analysis appears to be a potentially useful way to evaluate outcomes of patients enrolled in clinical trials in stroke. The results of the analysis have clinical relevance and can further explain differences in responses to therapies. In addition, the analysis allows for improved comparisons of results among clinical trials.

Effect of blood pressure on 3-month functional outcome in the subacute stage of ischemic stroke

“…Recently it was suggested that this method is useful for detecting a true signal and improving study power. 30,31 The simple dichotomization of function outcome (mRS scores 0-2 vs 3-5), which was performed as a sensitivity analysis in this study, provided similar results.…”

“…During the acute stage of ischemic stroke, high BP variability may be associated with lesion growth. 4,29 Autoregulation may also be impaired in the subacute stage, 30,31 and a hypoperfused brain is more likely to be affected by systemic BP changes. However, it should be noted that these explanations are speculative.…”

Factors Influencing Clinically Meaningful Recanalization after IV-rtPA in Acute Ischemic Stroke

“…NIHSS was divided into 4 categories of severity as previously published: 0 ϭ NIHSS 0 -7; 1 ϭ NIHSS 8 -14; 2 ϭ NIHSS 15-20; 3 ϭ NIHSS Ͼ20. 21 For occlusion location, proximal occlusions (ICAproximal M1) were scored 1 and distal occlusions (distal M1-M4) were scored 0. The CMR score was the sum of the stratified NIHSS score plus the occlusion score; the total CMR score for each patient ranged from 0 -4.…”

Favorable Influence of Subclinical Hypothyroidism on the Functional Outcomes in Stroke Patients

“…On both the 30 th and 90 th day, stroke outcomes were assessed using two different criteria. In the first outcome model, favorable outcomes [I] were simply defined by mRS scores (≦ 1), while the favorable outcomes [II], a method by Adams et al, were defined as follows: a) a 90-day mRS score of 0, if the baseline NIHSS scores were < 8, b) a mRS score of 0 or 1, if the NIHSS scores were 8-14, c) a mRS score 0-2, if the NIHSS scores were > 14 points [27].…”