title: Addition of sodium criterion to SOAR stroke score.
abstract: OBJECTIVE
  To examine the usefulness of including sodium (Na) levels as a criterion to the SOAR stroke score in predicting inpatient and 7-day mortality in stroke.
  
  
  METHODS
  Data from the Norfolk and Norwich University Hospital Stroke & TIA register (2003-2015) were analysed. Univariate and then multivariate models controlling for SOAR variables were used to assess the association between admission sodium levels and inpatient and 7-day mortality. The prognostic ability of the SOAR and SOAR Na scores for mortality outcomes at both time points were then compared using the Area Under the Curve (AUC) values from the Receiver Operating Characteristic curves.
  
  
  RESULTS
  A total of 8493 cases were included (male=47.4%, mean (SD) 77.7 (11.6) years). Compared with normonatremia (135-145 mmol/L), hypernatraemia (>145 mmol/L) was associated with inpatient mortality and moderate (125-129 mmol/L) and severe hypontraemia (<125 mmol/L) with 7-day mortality after adjustment for stroke type, Oxfordshire Community Stroke Project classification, age, prestroke modified Rankin score and sex. The SOAR and SOAR-Na scores both performed well in predicting inpatient mortality with AUC values of .794 (.78-.81) and .796 (.78-.81), respectively. 7-day mortality showed similar results. Both scores were less predictive in those with chronic kidney disease (CKD) and more so in those with hypoglycaemia.
  
  
  CONCLUSIONS
  The SOAR-Na did not perform considerably better than the SOAR stroke score. However, the performance of SOAR-Na in those with CKD and dysglycaemias requires further investigation.
authors.affiliation: Epidemiology Group, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: I R
authors.identifier: http://orcid.org/0000-0002-3142-6165
authors.initials: IR
authors.lastname: Adekunle-Olarinde
authors.affiliation: Epidemiology Group, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK.|Nuffield Department of Population Health, University of Oxford, Oxford, UK.
authors.forename: S J
authors.initials: SJ
authors.lastname: McCall
authors.affiliation: Epidemiology Group, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: R S
authors.initials: RS
authors.lastname: Barlas
authors.affiliation: Epidemiology Group, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: A D
authors.initials: AD
authors.lastname: Wood
authors.affiliation: Norwich Medical School, University of East Anglia, Norwich, UK.
authors.forename: A B
authors.initials: AB
authors.lastname: Clark
authors.affiliation: Clinical Informatics, Department of Medicine, University of Cambridge, Cambridge, UK.|Norfolk and Norwich University Hospital, Norwich, UK.
authors.forename: J H
authors.initials: JH
authors.lastname: Bettencourt-Silva
authors.affiliation: Norfolk and Norwich University Hospital, Norwich, UK.
authors.forename: A K
authors.initials: AK
authors.lastname: Metcalf
authors.affiliation: Norwich Medical School, University of East Anglia, Norwich, UK.|Norfolk and Norwich University Hospital, Norwich, UK.
authors.forename: K M
authors.initials: KM
authors.lastname: Bowles
authors.affiliation: Health Services Research Unit, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK.|Academic Department of Medicine for the Elderly, Aberdeen Royal Infirmary, NHS Grampian, Aberdeen, UK.
authors.forename: R L
authors.initials: RL
authors.lastname: Soiza
authors.affiliation: Norwich Medical School, University of East Anglia, Norwich, UK.|Norfolk and Norwich University Hospital, Norwich, UK.
authors.forename: J F
authors.initials: JF
authors.lastname: Potter
authors.affiliation: Epidemiology Group, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK.|Academic Department of Medicine for the Elderly, Aberdeen Royal Infirmary, NHS Grampian, Aberdeen, UK.
authors.forename: P K
authors.initials: PK
authors.lastname: Myint
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D005260:Female; D017052:Hospital Mortality / Q000639:trends; D006760:Hospitalization / Q000639:trends; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012720:Severity of Illness Index; D012964:Sodium / Q000097:blood*; D020521:Stroke / Q000097:blood* / Q000175:diagnosis* / Q000401:mortality
chemical_list: D015415:Biomarkers; D012964:Sodium
keywords: acute stroke; dysnatremia; mortality; prognosis