Browsing by Author "Prabhakaran, Shyam"

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    Probing the Effective Treatment Thresholds for Alteplase in Acute Ischemic Stroke With Regression Discontinuity Designs.
    (Frontiers in neurology, 2020-01) Naidech, Andrew M; Lawlor, Patrick N; Xu, Haolin; Fonarow, Gregg C; Xian, Ying; Smith, Eric E; Schwamm, Lee; Matsouaka, Roland; Prabhakaran, Shyam; Marinescu, Ioana; Kording, Konrad P
    Randomized Controlled Trials (RCTs) are considered the gold standard for measuring the efficacy of medical interventions. However, RCTs are expensive, and use a limited population. Techniques to estimate the effects of stroke interventions from observational data that minimize confounding would be useful. We used regression discontinuity design (RDD), a technique well-established in economics, on the Get With The Guidelines-Stroke (GWTG-Stroke) data set. RDD, based on regression, measures the occurrence of a discontinuity in an outcome (e.g., odds of home discharge) as a function of an intervention (e.g., alteplase) that becomes significantly more likely when crossing the threshold of a continuous variable that determines that intervention (e.g., time from symptom onset, since alteplase is only given if symptom onset is less than e.g., 3 h). The technique assumes that patients near either side of a threshold (e.g., 2.99 and 3.01 h from symptom onset) are indistinguishable other than the use of the treatment. We compared outcomes of patients whose estimated onset to treatment time fell on either side of the treatment threshold for three cohorts of patients in the GWTG-Stroke data set. This data set spanned three different treatment thresholds for alteplase (3 h, 2003-2007, N = 1,869; 3 h, 2009-2016, N = 13,086, and 4.5 h, 2009-2016, N = 6,550). Patient demographic characteristics were overall similar across the treatment thresholds. We did not find evidence of a discontinuity in clinical outcome at any treatment threshold attributable to alteplase. Potential reasons for failing to find an effect include violation of some RDD assumptions in clinical care, large sample sizes required, or already-well-chosen treatment threshold.
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    Race-Ethnic Disparities in Rates of Declination of Thrombolysis for Stroke.
    (Neurology, 2022-04) Mendelson, Scott J; Zhang, Shuaiqi; Matsouaka, Roland; Xian, Ying; Shah, Shreyansh; Lytle, Barbara L; Solomon, Nicole; Schwamm, Lee H; Smith, Eric E; Saver, Jeffrey L; Fonarow, Gregg; Holl, Jane; Prabhakaran, Shyam

    Background and objectives

    Prior regional or single-center studies have noted that 4% to 7% of eligible patients with acute ischemic stroke (AIS) decline IV tissue plasminogen activator (tPA). We sought to determine the prevalence of tPA declination in a nationwide registry of patients with AIS and to investigate differences in declination by race/ethnicity.

    Methods

    We used the Get With The Guidelines-Stroke registry to identify patients with AIS eligible for tPA and admitted to participating hospitals between January 1, 2016, and March 28, 2019. We compared patient demographics and admitting hospital characteristics between tPA-eligible patients who received and those who declined tPA. Using multivariable logistic regression, we determined patient and hospital factors associated with tPA declination.

    Results

    Among 177,115 tPA-eligible patients with AIS at 1,976 sites, 6,545 patients (3.7%) had tPA declination as the sole documented reason for not receiving tPA. Patients declining treatment were slightly older, were more likely to be female, arrived more often at off-hours and earlier after symptom onset, and were more likely to present to Primary Stroke Centers. Compared with non-Hispanic White, non-Hispanic Black race/ethnicity was independently associated with increased (adjusted odds ratio [aOR] 1.21, 95% CI 1.11-1.31), Asian race/ethnicity with decreased (aOR 0.72, 95% CI 0.58-0.88), and Hispanic ethnicity (any race) with similar odds of tPA declination (OR 0.98, 95% CI 0.86-1.13) in multivariable analysis.

    Discussion

    Although the overall prevalence of tPA declination is low, eligible non-Hispanic Black patients are more likely and Asian patients less likely to decline tPA than non-Hispanic White patients. Reducing rates of tPA declinations among non-Hispanic Black patients may be an opportunity to address disparities in stroke care.