title: Validity of a Modified Sequential Organ Failure Assessment Score Using the Richmond Agitation-Sedation Scale.
abstract: OBJECTIVE
  The Sequential Organ Failure Assessment and other severity of illness scales rely on the Glasgow Coma Scale to measure acute neurologic dysfunction, but the Glasgow Coma Scale is unavailable or inconsistently applied in some institutions. The objective of this study was to assess the validity of a modified Sequential Organ Failure Assessment that uses the Richmond Agitation-Sedation Scale instead of Glasgow Coma Scale.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Medical and surgical ICUs within a large, tertiary care hospital.
  
  
  METHODS
  Critically ill medical/surgical ICU patients.
  
  
  METHODS
  We calculated daily Sequential Organ Failure Assessment scores by using electronic medical record-derived data. By using bedside nurse-recorded Glasgow Coma Scale and Richmond Agitation-Sedation Scale measures, we calculated neurologic Sequential Organ Failure Assessment scores using the original Glasgow Coma Scale-based approach and a novel Richmond Agitation-Sedation Scale-based approach, converting the 10-point Richmond Agitation-Sedation Scale to a 4-point neurologic Sequential Organ Failure Assessment score. We assessed construct validity of Richmond Agitation-Sedation Scale-based Sequential Organ Failure Assessment by analyzing correlations with established severity of illness constructs (Acute Physiology and Chronic Health Evaluation II and Glasgow Coma Scale-based Sequential Organ Failure Assessment) and predictive validity by using logistic regression to determine whether Richmond Agitation-Sedation Scale-based Sequential Organ Failure Assessment predicts ICU, hospital, and 1-year mortality. We assessed discriminative performance with c-statistics.
  
  
  RESULTS
  Among 513 patients (5,199 patient-days), Richmond Agitation-Sedation Scale-based Sequential Organ Failure Assessment was strongly correlated with Acute Physiology and Chronic Health Evaluation II acute physiology score at enrollment (r = 0.583; 95% CI, 0.518-0.642) and daily Glasgow Coma Scale-based Sequential Organ Failure Assessment scores (r = 0.963; 95% CI, 0.956-0.968). Mean Richmond Agitation-Sedation Scale-based Sequential Organ Failure Assessment scores predicted ICU mortality (areas under the curve = 0.814)-as did mean Glasgow Coma Scale-based Sequential Organ Failure Assessment (0.799)-as well as hospital and 1-year mortality. Admission Sequential Organ Failure Assessment scores, whether using Richmond Agitation-Sedation Scale or Glasgow Coma Scale, were less accurate predictors of mortality; areas under the curves for ICU mortality for Richmond Agitation-Sedation Scale-based and Glasgow Coma Scale-based Sequential Organ Failure Assessment, for example, were 0.622 and 0.608, respectively.
  
  
  CONCLUSIONS
  A modified Sequential Organ Failure Assessment score that uses bedside Richmond Agitation-Sedation Scale when Glasgow Coma Scale data are not available is a valid means of assessing daily severity of illness in the ICU and may be valuable for risk-adjustment and benchmarking purposes.
authors.affiliation: 1Center for Health Services Research, Vanderbilt University School of Medicine, Nashville, TN.2Section of Hospital Medicine, Division of General Internal Medicine and Public Health, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN.3Geriatric Research, Education, and Clinical Center (GRECC) Service, Department of Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, TN.4Division of Critical Care, Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN.5Anesthesia Service, Department of Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, TN.6Department of Urology, Vanderbilt University School of Medicine, Nashville, TN.7Department of Clinical Epidemiology and Biostatistics, Graduate School of Medicine, Osaka University, Osaka, Japan.8Advanced Medical Emergency and Critical Care Center, Yamaguchi University Hospital, Yamaguchi, Japan.9Division of Allergy, Pulmonary, and Critical Care Medicine, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN.
authors.forename: Eduard E
authors.initials: EE
authors.lastname: Vasilevskis
authors.forename: Pratik P
authors.initials: PP
authors.lastname: Pandharipande
authors.forename: Amy J
authors.initials: AJ
authors.lastname: Graves
authors.forename: Ayumi
authors.initials: A
authors.lastname: Shintani
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Tsuruta
authors.forename: E Wesley
authors.initials: EW
authors.lastname: Ely
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Girard
mesh_terms: D003243:Consciousness; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000175:diagnosis* / Q000401:mortality*; D063305:Organ Dysfunction Scores; D011379:Prognosis; D011446:Prospective Studies; D011595:Psychomotor Agitation; D015203:Reproducibility of Results