Dataset Information

Application of beta regression to analyze ischemic stroke volume in NINDS rt-PA clinical trials.

ABSTRACT:

Background and purpose

Ischemic stroke lesion volumes have proven difficult to analyze due to the extremely skewed shape of their underlying distribution. We introduce an extension of generalized linear models, beta regression, as a possible method of modeling extremely skewed distributions as evidenced in ischemic stroke lesion volumes.

Methods

The NINDS rt-PA clinical trials measured ischemic stroke lesion volume as a secondary trial outcome. Three-month lesion volumes from these trials were analyzed using beta regression. A multi-variable regression model associating explanatory variables with ischemic stroke lesion volumes was constructed using accepted model building strategies and compared with the previously published volumetric analysis.

Results

Beta regression produced a similar model when compared to the previous analysis published by the study group. All previously identified variables of importance were detected in the model building process. The age by treatment interaction described in previous studies was also found in this analysis, confirming the strong effect age has on stroke outcomes. Further, a treatment effect was elicited in terms of odds ratios, yielding a previously unknown quantification of the effect of rt-PA on lesion volumes.

Conclusions

Beta regression proved adept in modeling ischemic stroke lesions and offered the interpretation of covariates in terms of odds ratios. Beta regression is seen as a legitimate alternative to analyze ischemic stroke volumes.

SUBMITTER: Swearingen CJ

PROVIDER: S-EPMC3186717 | biostudies-literature | 2011

REPOSITORIES: biostudies-literature

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Publications

Application of beta regression to analyze ischemic stroke volume in NINDS rt-PA clinical trials.

Swearingen Christopher J CJ Tilley Barbara C BC Adams Robert J RJ Rumboldt Zoran Z Nicholas Joyce S JS Bandyopadhyay Dipankar D Woolson Robert F RF

Neuroepidemiology 20110901 2

<h4>Background and purpose</h4>Ischemic stroke lesion volumes have proven difficult to analyze due to the extremely skewed shape of their underlying distribution. We introduce an extension of generalized linear models, beta regression, as a possible method of modeling extremely skewed distributions as evidenced in ischemic stroke lesion volumes.<h4>Methods</h4>The NINDS rt-PA clinical trials measured ischemic stroke lesion volume as a secondary trial outcome. Three-month lesion volumes from thes ...[more]

PMID: 21894044

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Project description:Background and purposeSince Food and Drug Administration approval of intravenous tissue-type plasminogen activator (tPA) for treatment of acute ischemic stroke in 1996, it has become clear that several criteria used for exclusion from therapy were not based on actual data or operationally defined for use in clinical practice. All eligibility criteria from the National Institute of Neurological Disorders and Stroke (NINDS) recombinant tPA Stroke Study were adopted within the alteplase package insert as contraindications/warnings. Many clinicians have expressed the need for clarification and better definition of these treatment criteria.MethodsA group of investigators who also practice as stroke physicians convened a collaborative endeavor to work toward developing more clinically meaningful and consensus-driven exclusion criteria for intravenous tPA. The first of these exclusion criteria chosen was rapidly improving stroke symptoms (RISS). We reviewed and clarified the historical context and intention with the original investigators, held e-mail discussions, convened an in-person RISS Summit, and obtained the understanding of experienced stroke physicians broadly.ResultsHistorically, the intent of this exclusion criterion within the NINDS recombinant tPA Stroke Trial was to avoid treatment of transient ischemic attacks-who would have recovered completely without treatment. There was unanimous consensus that, in the absence of other contraindications, patients who experience improvement of any degree, but have a persisting neurological deficit that is potentially disabling, should be treated with intravenous tPA. This statement is supported from the methods established for the original NINDS trial, on the basis of detailed discussions and interviews with the former NINDS trialists. It was agreed that improvement should only be monitored for the extent of time needed to prepare and administer the intravenous tPA bolus/infusion. An explicit operational definition of RISS was developed by consensus to guide future decision making in acute stroke. There was unanimous agreement that all neurological deficits present at the time of the treatment decision should be considered in the context of individual risk and benefit, as well as the patient's baseline functional status.ConclusionsA structured framework and quantitative approach toward defining RISS emerged through expert opinion and consensus. The term, RISS, should be reserved for those who improve to a mild deficit, specifically one which is perceived to be nondisabling. This is recommended to guide decision making on intravenous tPA eligibility going forward, including the design of future studies. An additional study of patients with rapid improvement to nonmild deficits is not justified because these patients should be treated.

Project description:ObjectiveTo evaluate the clinical efficacy of intravenous thrombolysis with recombinant tissue-type plasminogen activator (rt-PA) for acute ischemic stroke.MethodsA total of 76 patients with acute ischemic stroke admitted to the Encephalopathy Dept. of Zhecheng Hospital of Traditional Chinese Medicine between February 2021 and June 2022 were recruited in this prospective trial (ClinicalTrials.gov, NCT03884410) and patients were randomized 1:1 to receive either aspirin plus clopidogrel (control group) or aspirin plus clopidogrel and rt-PA intravenous thrombolytic therapy (experimental group), with 38 cases in each group. The treatment efficiency, National Institute of Health stroke scale (NIHSS) scores, daily living ability, coagulation function, serum Lipoprotein-associated phospholipaseA2 (Lp-PLA2), homocysteine (HCY), hypersensitive C-reactive protein (hsCRP) levels, adverse events, and prognosis were evaluated and compared between the two groups.ResultsIntravenous thrombolysis with rt-PA resulted in a better treatment outcome of patients versus aspirin plus clopidogrel (P<0.05). Patients with rt-PA exhibited better improvement in neurological function than those with aspirin plus clopidogrel, as shown by the lower NIHSS scores (P<0.05). Intravenous thrombolysis with rt-PA resulted in a better quality of life of patients than aspirin plus clopidogrel, indicated by the higher Barthel Index (BI) levels (P<0.05). The lower von Willebrand factor (vWF) and Factor VIII (F) levels indicated better coagulation function of patients with rt-PA versus those with aspirin plus clopidogrel (P<0.05). The lower serum concentrations of Lp-PLA2, HCY, and hsCRP suggested patients with rt-PA had milder inflammatory responses versus those without rt-PA (P<0.05). There was no significant difference in the incidence of adverse events in the two groups (P>0.05). Intravenous thrombolytic therapy with rt-PA better enhanced the prognosis of patients than with aspirin plus clopidogrel (P<0.05).ConclusionCompared with conventional pharmacological regimens, additional rt-PA intravenous thrombolytic therapy improves the clinical outcome of patients with acute ischemic stroke, promotes neurological recovery, and enhances patient prognosis without increasing the risk of patient-related adverse events.

Dataset Information

Application of beta regression to analyze ischemic stroke volume in NINDS rt-PA clinical trials.

Background and purpose

Methods

Results

Conclusions

Publications

Application of beta regression to analyze ischemic stroke volume in NINDS rt-PA clinical trials.

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