Centre Cérébrovasculaire PREDICTIVE VALUE OF THE ASTRAL SCORE, THE CHARLSON AND THE ELIXHAUSER COMORBIDITY INDEXES IN ACUTE ISCHEMIC STROKE Kakaletsis Nikolaos 1, Papavasileiou Vasileios 1, Lambrou Dimitrios 2, Eskandari Ashraf 2,Ntaios George 2, Michel Patrik 2 Department of Clinical Neurosciences and Preventive Medicine, Danube University in Krems, Austria 2. Stroke Center, Neurology Service, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland. LARISSA  21 March 2015

Introduction Comorbidity has been shown to be highly prevalent in stroke patients, especially in the older population. The phenomenon of comorbidity is relevant because it often has a negative impact on health outcomes, quality of life, and health care use. There is limited information on the prevalence and impact of comorbidities in stroke patients. Clinical prognostic models in acute stroke would be helpful in predicting outcome in future patients (informing them and their relatives of reasons for treatment and clinical decisions, creating clinical risk groups and stratifying patients by disease severity in clinical trials). Definitions: Comorbidity The medical conditions that exist at the time of diagnosis of the index disease or later, but that are not a consequence of the index disease and it is likely to be a significant factor influencing mortality and resource use in the hospital Guralnik JM. Assessing the impact of comorbidity in the older population. Ann Epidemiol. 1996;6(5):376-80. van den Akker et al. Multimorbidity in general practice: prevalence, incidence, and determinants of co-occurring chronic and recurrent diseases. J Clin Epidemiol. 1998;51(5):367-75. Gijsen R, eta al. Causes and consequences of comorbidity: a review. J Clin Epidemiol. 2001;54(7):661-74. Ording AG, et al. Concepts of comorbidities, multiple morbidities, complications, and their clinical epidemiologic analogs. Clin Epidemiol. 2013;5:199-203. Feinstein AR. The pre-therapeutic classification of co-morbidity in chronic disease. Journal of Chronic Diseases. 1970;23(7):455-68.

Aim - Methods We assessed 3,099 consecutive AIS patients from the Acute Stroke Registry and Analysis of Lausanne (ASTRAL) regarding unfavorable functional outcome, (mRS>2) and mortality at 7 days, 3 and 12 months. C-statistics (AUC: area under the receiver-operating-characteristic [ROC] curve) were calculated as measures of discrimination. 1 indicating perfect prediction and 0.5 indicating chance prediction. 0.7-0.8 can be considered as acceptable 0.8-0.9 as excellent The aim was to evaluate the prognostic value of the Charlson/Deyo and Elixhauser comorbidity indexes (CI) on functional outcome and mortality in patients with acute ischemic stroke (AIS) in short-, medium- and long-term and to test whether they can add further predictive value in addition to the existing clinical predictive model (ASTRAL-score). ASTRAL is the prospective registry of all consecutive patients admitted to the stroke unit or intensive care unit of the Central University Hospital of Vaud (CHUV) with acute ischemic stroke within 24 hours after last proof of well-being.

Charlson’s Comorbidity Index : Elixhauser’s Comorbidity Index: ASTRAL-score: Was introduced recently for the prognosis of functional outcome in patients with AIS It has been externally validated in three independent and ethnically diverse cohorts, showing remarkable consistency on predicting three-month functional outcome Recently, it was validated externally for the prognosis of five-year dependence and mortality Charlson’s Comorbidity Index : A weighted sum of presence or absence of each of the 19 conditions Was developed as a prognostic index to predict 1-year mortality among patients admitted to the medical service of an acute care hospital (treated for primary breast cancer) Two adaptations for use with International Classification of Disease, 9th Revision, Clinical Modification (ICD-9-CM) codes in administrative databases were made by Deyo et al. Elixhauser’s Comorbidity Index: Includes 30 categories of comorbid conditions, and it was developed using administrative data for the prediction of length of stay, hospital charges, and in-hospital death Elixhauser’s Comorbidity Index van Walraven modification Hypertension - Diabetesuncomplicated - Diabetes, complicated – Hypothyroidism - Peptic ulcer disease, no bleeding - AIDS/HIV - Alcohol abuse - Psychosis 2 Peripheral vascular disorders 3 Chronic pulmonary disease – Coagulopathy - Rheumatoid arthritis/collagen vascular diseases 4 Pulmonary circulation disorders - Solid tumor without metastasis 5 Fluid and electrolyte disorders - Renal failure - Cardiac arrhythmias 6 Weight loss Neurodegenerative disorders 7 Congestive heart failure - Paralysis 9 Lymphoma 11 Liver disease 12 Metastatic cancer -1 Valvular disease -2 Blood loss anemia - Deficiency anemia -3 Depression -4 Obesity -7 Drug abuse Charlson’s Comorbidity Index (weighted index of comorbidity) 1 Myocardial infarct Congestive heart failure Peripheral vascular disease Cerebrovascular disease Dementia Chronic pulmonary disease Connective tissue disease Ulcer disease Mild liver disease Diabetes 2 Hemiplegia Moderate or severe renal disease Diabetes with end organ damage Any tumor Together at Deyo-modified CCI Leukemia Lymphoma 3 Moderate or severe liver disease 6 Metastatic solid tumor AIDS Integer-based prognostic ASTRAL-score for the calculation of probability of unfavorable outcome in patients with acute ischemic stroke Covariates Score points Age: for every 5 y a 1 Severity: for every NIHSS point a Time delay from onset to admission>3hb 2 Range of visual field defect c Acute glucose>7.3 or<3.7 mmol/L d Level of consciousness decreased e 3 ASTRAL score Age, Severity, Time delay between stroke onset (or last proof of good health) and admission; R Range of visual field defect; A Acute glucose; and L Level of consciousness; NIHSS NIH Stroke Scale. a. Counted from 0, b. 0 points when onset-to-admission time was 3 hours, c. 2 points for any stroke-related visual field defect; 0 points in the absence of visual field defect, d. 0 points for glucose 3.7 and 7.3 mmol/L, e. 0 points for normal level of consciousness.

RESULTS Conclusions The ASTRAL-score is better predictor of AIS outcome (functional outcome or death) than Charlson/Deyo and Elixhauser CIs in short-, medium- and long-term. It may be statistically improved with the addition of the Charlson/Deyo CI, but this addition is of limited clinically use because of its complex calculation.