Modest association between the discharge modified Rankin Scale score and symptomatic intracerebral hemorrhage after intravenous thrombolysis

Abstract

Background: Thirty- and 90-day modified Rankin Scale (mRS) scores are used to monitor adverse outcome or symptomatic intracerebral hemorrhage (sICH) in ischemic stroke patients after intravenous (IV) thrombolytic therapy. Discharge mRS scores are more readily available and could serve as a proxy for 30- or 90-day mRS data. Our goal was to evaluate agreement between the discharge mRS score and sICH. Additionally, we tested for correlations between the discharge mRS score and 8 clinical scores developed to predict sICH or adverse outcomes based on 90-day mRS data.

Methods: Clinical data were analyzed from 210 patients receiving IV thrombolysis from January 2009 till December 2013 at the Yale New Haven Hospital. Agreement between sICH and the discharge mRS score was assessed using linear kappa. Eight clinical scores were calculated for each patient and compared with the discharge mRS score by univariate logistic regression. Goodness of fit was tested by receiver operating characteristic (ROC) analysis and by Hosmer-Lemeshow statistics.

Results: We found only modest agreement between sICH and unfavorable discharge mRS scores (mRS ≥ 5), with kappa .22, P = .0001. All 8 clinical scores tested showed good agreement with discharge mRS score of 5 or more (ROC area >.7).

Conclusions: The discharge mRS score shows only modest agreement with sICH and therefore cannot be recommended as a proxy for 30- or 90-day mRS data. However, the discharge mRS score correlates strongly with clinical scores predicting long-term adverse outcome; therefore, assessment of discharge mRS scores may be of some clinical benefit.

Keywords: IV thrombolysis; Ischemic stroke; alteplase; hemorrhagic transformation; modified Rankin scale; symptomatic intracerebral hemorrhage.