Abstract WP69: Days Alive And Out Of Hospital As A Measure Of Stroke Outcome In Patients Receiving Hyperacute Stroke Intervention

Abstract

Background: Patient outcome after stroke is frequently assessed with the modified Rankin Scale score (mRS), which is a 7-level ordinal scale from 0 - no disability, to 6- dead that is usually obtained by in-person or telephone interviews. The mRS can be prone to bias and can have significant inter-rater variability. Days alive and out of hospital at 90 days (DAOH-90) is an objective, readily available outcome measure that accounts for survival, time spent in hospital or rehabilitation settings, re-admission, and institutionalization. We aimed to assess the criterion, construct and face validity of DAOH. Methods: Consecutive ischemic stroke patients treated with thrombolysis or endovascular thrombectomy were used in this analysis. DAOH-90 was calculated from the national minimum dataset, an administrative nationwide database. mRS at 90 days was assessed with in-person or telephone interviews. Simple descriptive statistics were applied (median [IQR]). The ability of DAOH-90 to distinguish between the commonly applied cut-points of mRS-90 was assessed using the area under the receiver operating curve (AUROC). The associations of DAOH-90 with commonly used stroke prognostic variables were assessed with Spearman’s correlation. Results: 1067 ischemic stroke patients (481 male, median age 69 [58-78], median NIHSS 16 [11-20] were included in this study. Overall, median DAOH-90 was 68 [25-82] and median mRS-90 was 2 [1-4]. There was a strong association between mRS-90 and DAOH-90 (Spearman's rho correlation 0.79, p<0.001). AUROC (95% CI) for predicting mRS>0, mRS>1, mRS>2 were 0.85 (0.83-0.88), AUC 0.88 (0.86-0.90), AUC 0.90 (0.88-0.92) respectively. DAOH-90 was significantly correlated with age (spearman rho -0.37, p=0.002), admission NIHSS (spearman rho -0.37, p<0.001), Alberta stroke programme early CT score (spearman rho 0.23, p<0.001), and admission blood glucose concentration (spearman rho -0.24, p<0.001). Conclusion: DAOH is statistically valid outcome measure in ischemic stroke that strongly relates to mRS at 90 days. DAOH is an objective, patient-centric outcome measure that can be determined from large datasets and therefore its place in stroke research warrants further study.