title: Field Validation of the Los Angeles Motor Scale as a Tool for Paramedic Assessment of Stroke Severity.
abstract: The Los Angeles Motor Scale (LAMS) is a 3-item, 0- to 10-point motor stroke-deficit scale developed for prehospital use. We assessed the convergent, divergent, and predictive validity of the LAMS when performed by paramedics in the field at multiple sites in a large and diverse geographic region.
  
  
  
  We analyzed early assessment and outcome data prospectively gathered in the FAST-MAG trial (Field Administration of Stroke Therapy-Magnesium phase 3) among patients with acute cerebrovascular disease (cerebral ischemia and intracranial hemorrhage) within 2 hours of onset, transported by 315 ambulances to 60 receiving hospitals.
  
  
  
  Among 1632 acute cerebrovascular disease patients (age 70±13 years, male 57.5%), time from onset to prehospital LAMS was median 30 minutes (interquartile range 20-50), onset to early postarrival (EPA) LAMS was 145 minutes (interquartile range 119-180), and onset to EPA National Institutes of Health Stroke Scale was 150 minutes (interquartile range 120-180). Between the prehospital and EPA assessments, LAMS scores were stable in 40.5%, improved in 37.6%, and worsened in 21.9%. In tests of convergent validity, against the EPA National Institutes of Health Stroke Scale, correlations were r=0.49 for the prehospital LAMS and r=0.89 for the EPA LAMS. Prehospital LAMS scores did diverge from the prehospital Glasgow Coma Scale, r=-0.22. Predictive accuracy (adjusted C statistics) for nondisabled 3-month outcome was as follows: prehospital LAMS, 0.76 (95% confidence interval 0.74-0.78); EPA LAMS, 0.85 (95% confidence interval 0.83-0.87); and EPA National Institutes of Health Stroke Scale, 0.87 (95% confidence interval 0.85-0.88).
  
  
  
  In this multicenter, prospective, prehospital study, the LAMS showed good to excellent convergent, divergent, and predictive validity, further establishing it as a validated instrument to characterize stroke severity in the field.
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K.); Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea (P.-W.C.); Department of Emergency Medicine and Neurology (S.S.), Department of Emergency (F.D.P.), Department of Neurology and Comprehensive Stroke Center (D.S.L., L.S., L.R., M.V.-S., J.L.S.), Neurovascular Imaging Research Core (D.S.L.), and Department of Biomathematics (J.G.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, University of Southern California, Los Angeles (N.S., M.-K.T.); Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.J.S.); Department of Emergency Medicine, Keck School of Medicine of the University of Southern California and Los Angeles Fire Department (M.E.); Los Angeles County Department of Public Health, CA (F.D.P.); National Institutes of Health, National Institutes of Neurological Disorders and Stroke, Bethesda, MD (R.C.); and School of Medicine, Stanford University, Palo Alto, CA (S.H.).
authors.forename: Joon-Tae
authors.initials: JT
authors.lastname: Kim
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K.); Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea (P.-W.C.); Department of Emergency Medicine and Neurology (S.S.), Department of Emergency (F.D.P.), Department of Neurology and Comprehensive Stroke Center (D.S.L., L.S., L.R., M.V.-S., J.L.S.), Neurovascular Imaging Research Core (D.S.L.), and Department of Biomathematics (J.G.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, University of Southern California, Los Angeles (N.S., M.-K.T.); Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.J.S.); Department of Emergency Medicine, Keck School of Medicine of the University of Southern California and Los Angeles Fire Department (M.E.); Los Angeles County Department of Public Health, CA (F.D.P.); National Institutes of Health, National Institutes of Neurological Disorders and Stroke, Bethesda, MD (R.C.); and School of Medicine, Stanford University, Palo Alto, CA (S.H.).
authors.forename: Pil-Wook
authors.initials: PW
authors.lastname: Chung
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K.); Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea (P.-W.C.); Department of Emergency Medicine and Neurology (S.S.), Department of Emergency (F.D.P.), Department of Neurology and Comprehensive Stroke Center (D.S.L., L.S., L.R., M.V.-S., J.L.S.), Neurovascular Imaging Research Core (D.S.L.), and Department of Biomathematics (J.G.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, University of Southern California, Los Angeles (N.S., M.-K.T.); Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.J.S.); Department of Emergency Medicine, Keck School of Medicine of the University of Southern California and Los Angeles Fire Department (M.E.); Los Angeles County Department of Public Health, CA (F.D.P.); National Institutes of Health, National Institutes of Neurological Disorders and Stroke, Bethesda, MD (R.C.); and School of Medicine, Stanford University, Palo Alto, CA (S.H.).
authors.forename: Sidney
authors.initials: S
authors.lastname: Starkman
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K.); Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea (P.-W.C.); Department of Emergency Medicine and Neurology (S.S.), Department of Emergency (F.D.P.), Department of Neurology and Comprehensive Stroke Center (D.S.L., L.S., L.R., M.V.-S., J.L.S.), Neurovascular Imaging Research Core (D.S.L.), and Department of Biomathematics (J.G.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, University of Southern California, Los Angeles (N.S., M.-K.T.); Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.J.S.); Department of Emergency Medicine, Keck School of Medicine of the University of Southern California and Los Angeles Fire Department (M.E.); Los Angeles County Department of Public Health, CA (F.D.P.); National Institutes of Health, National Institutes of Neurological Disorders and Stroke, Bethesda, MD (R.C.); and School of Medicine, Stanford University, Palo Alto, CA (S.H.).
authors.forename: Nerses
authors.initials: N
authors.lastname: Sanossian
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K.); Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea (P.-W.C.); Department of Emergency Medicine and Neurology (S.S.), Department of Emergency (F.D.P.), Department of Neurology and Comprehensive Stroke Center (D.S.L., L.S., L.R., M.V.-S., J.L.S.), Neurovascular Imaging Research Core (D.S.L.), and Department of Biomathematics (J.G.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, University of Southern California, Los Angeles (N.S., M.-K.T.); Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.J.S.); Department of Emergency Medicine, Keck School of Medicine of the University of Southern California and Los Angeles Fire Department (M.E.); Los Angeles County Department of Public Health, CA (F.D.P.); National Institutes of Health, National Institutes of Neurological Disorders and Stroke, Bethesda, MD (R.C.); and School of Medicine, Stanford University, Palo Alto, CA (S.H.).
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Stratton
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K.); Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea (P.-W.C.); Department of Emergency Medicine and Neurology (S.S.), Department of Emergency (F.D.P.), Department of Neurology and Comprehensive Stroke Center (D.S.L., L.S., L.R., M.V.-S., J.L.S.), Neurovascular Imaging Research Core (D.S.L.), and Department of Biomathematics (J.G.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, University of Southern California, Los Angeles (N.S., M.-K.T.); Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.J.S.); Department of Emergency Medicine, Keck School of Medicine of the University of Southern California and Los Angeles Fire Department (M.E.); Los Angeles County Department of Public Health, CA (F.D.P.); National Institutes of Health, National Institutes of Neurological Disorders and Stroke, Bethesda, MD (R.C.); and School of Medicine, Stanford University, Palo Alto, CA (S.H.).
authors.forename: Marc
authors.initials: M
authors.lastname: Eckstein
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K.); Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea (P.-W.C.); Department of Emergency Medicine and Neurology (S.S.), Department of Emergency (F.D.P.), Department of Neurology and Comprehensive Stroke Center (D.S.L., L.S., L.R., M.V.-S., J.L.S.), Neurovascular Imaging Research Core (D.S.L.), and Department of Biomathematics (J.G.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, University of Southern California, Los Angeles (N.S., M.-K.T.); Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.J.S.); Department of Emergency Medicine, Keck School of Medicine of the University of Southern California and Los Angeles Fire Department (M.E.); Los Angeles County Department of Public Health, CA (F.D.P.); National Institutes of Health, National Institutes of Neurological Disorders and Stroke, Bethesda, MD (R.C.); and School of Medicine, Stanford University, Palo Alto, CA (S.H.).
authors.forename: Frank D
authors.initials: FD
authors.lastname: Pratt
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K.); Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea (P.-W.C.); Department of Emergency Medicine and Neurology (S.S.), Department of Emergency (F.D.P.), Department of Neurology and Comprehensive Stroke Center (D.S.L., L.S., L.R., M.V.-S., J.L.S.), Neurovascular Imaging Research Core (D.S.L.), and Department of Biomathematics (J.G.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, University of Southern California, Los Angeles (N.S., M.-K.T.); Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.J.S.); Department of Emergency Medicine, Keck School of Medicine of the University of Southern California and Los Angeles Fire Department (M.E.); Los Angeles County Department of Public Health, CA (F.D.P.); National Institutes of Health, National Institutes of Neurological Disorders and Stroke, Bethesda, MD (R.C.); and School of Medicine, Stanford University, Palo Alto, CA (S.H.).
authors.forename: Robin
authors.initials: R
authors.lastname: Conwit
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K.); Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea (P.-W.C.); Department of Emergency Medicine and Neurology (S.S.), Department of Emergency (F.D.P.), Department of Neurology and Comprehensive Stroke Center (D.S.L., L.S., L.R., M.V.-S., J.L.S.), Neurovascular Imaging Research Core (D.S.L.), and Department of Biomathematics (J.G.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, University of Southern California, Los Angeles (N.S., M.-K.T.); Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.J.S.); Department of Emergency Medicine, Keck School of Medicine of the University of Southern California and Los Angeles Fire Department (M.E.); Los Angeles County Department of Public Health, CA (F.D.P.); National Institutes of Health, National Institutes of Neurological Disorders and Stroke, Bethesda, MD (R.C.); and School of Medicine, Stanford University, Palo Alto, CA (S.H.).
authors.forename: David S
authors.initials: DS
authors.lastname: Liebeskind
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K.); Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea (P.-W.C.); Department of Emergency Medicine and Neurology (S.S.), Department of Emergency (F.D.P.), Department of Neurology and Comprehensive Stroke Center (D.S.L., L.S., L.R., M.V.-S., J.L.S.), Neurovascular Imaging Research Core (D.S.L.), and Department of Biomathematics (J.G.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, University of Southern California, Los Angeles (N.S., M.-K.T.); Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.J.S.); Department of Emergency Medicine, Keck School of Medicine of the University of Southern California and Los Angeles Fire Department (M.E.); Los Angeles County Department of Public Health, CA (F.D.P.); National Institutes of Health, National Institutes of Neurological Disorders and Stroke, Bethesda, MD (R.C.); and School of Medicine, Stanford University, Palo Alto, CA (S.H.).
authors.forename: Latisha
authors.initials: L
authors.lastname: Sharma
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K.); Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea (P.-W.C.); Department of Emergency Medicine and Neurology (S.S.), Department of Emergency (F.D.P.), Department of Neurology and Comprehensive Stroke Center (D.S.L., L.S., L.R., M.V.-S., J.L.S.), Neurovascular Imaging Research Core (D.S.L.), and Department of Biomathematics (J.G.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, University of Southern California, Los Angeles (N.S., M.-K.T.); Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.J.S.); Department of Emergency Medicine, Keck School of Medicine of the University of Southern California and Los Angeles Fire Department (M.E.); Los Angeles County Department of Public Health, CA (F.D.P.); National Institutes of Health, National Institutes of Neurological Disorders and Stroke, Bethesda, MD (R.C.); and School of Medicine, Stanford University, Palo Alto, CA (S.H.).
authors.forename: Lucas
authors.initials: L
authors.lastname: Restrepo
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K.); Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea (P.-W.C.); Department of Emergency Medicine and Neurology (S.S.), Department of Emergency (F.D.P.), Department of Neurology and Comprehensive Stroke Center (D.S.L., L.S., L.R., M.V.-S., J.L.S.), Neurovascular Imaging Research Core (D.S.L.), and Department of Biomathematics (J.G.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, University of Southern California, Los Angeles (N.S., M.-K.T.); Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.J.S.); Department of Emergency Medicine, Keck School of Medicine of the University of Southern California and Los Angeles Fire Department (M.E.); Los Angeles County Department of Public Health, CA (F.D.P.); National Institutes of Health, National Institutes of Neurological Disorders and Stroke, Bethesda, MD (R.C.); and School of Medicine, Stanford University, Palo Alto, CA (S.H.).
authors.forename: May-Kim
authors.initials: MK
authors.lastname: Tenser
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K.); Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea (P.-W.C.); Department of Emergency Medicine and Neurology (S.S.), Department of Emergency (F.D.P.), Department of Neurology and Comprehensive Stroke Center (D.S.L., L.S., L.R., M.V.-S., J.L.S.), Neurovascular Imaging Research Core (D.S.L.), and Department of Biomathematics (J.G.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, University of Southern California, Los Angeles (N.S., M.-K.T.); Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.J.S.); Department of Emergency Medicine, Keck School of Medicine of the University of Southern California and Los Angeles Fire Department (M.E.); Los Angeles County Department of Public Health, CA (F.D.P.); National Institutes of Health, National Institutes of Neurological Disorders and Stroke, Bethesda, MD (R.C.); and School of Medicine, Stanford University, Palo Alto, CA (S.H.).
authors.forename: Miguel
authors.initials: M
authors.lastname: Valdes-Sueiras
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K.); Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea (P.-W.C.); Department of Emergency Medicine and Neurology (S.S.), Department of Emergency (F.D.P.), Department of Neurology and Comprehensive Stroke Center (D.S.L., L.S., L.R., M.V.-S., J.L.S.), Neurovascular Imaging Research Core (D.S.L.), and Department of Biomathematics (J.G.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, University of Southern California, Los Angeles (N.S., M.-K.T.); Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.J.S.); Department of Emergency Medicine, Keck School of Medicine of the University of Southern California and Los Angeles Fire Department (M.E.); Los Angeles County Department of Public Health, CA (F.D.P.); National Institutes of Health, National Institutes of Neurological Disorders and Stroke, Bethesda, MD (R.C.); and School of Medicine, Stanford University, Palo Alto, CA (S.H.).
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Gornbein
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K.); Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea (P.-W.C.); Department of Emergency Medicine and Neurology (S.S.), Department of Emergency (F.D.P.), Department of Neurology and Comprehensive Stroke Center (D.S.L., L.S., L.R., M.V.-S., J.L.S.), Neurovascular Imaging Research Core (D.S.L.), and Department of Biomathematics (J.G.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, University of Southern California, Los Angeles (N.S., M.-K.T.); Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.J.S.); Department of Emergency Medicine, Keck School of Medicine of the University of Southern California and Los Angeles Fire Department (M.E.); Los Angeles County Department of Public Health, CA (F.D.P.); National Institutes of Health, National Institutes of Neurological Disorders and Stroke, Bethesda, MD (R.C.); and School of Medicine, Stanford University, Palo Alto, CA (S.H.).
authors.forename: Scott
authors.initials: S
authors.lastname: Hamilton
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K.); Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea (P.-W.C.); Department of Emergency Medicine and Neurology (S.S.), Department of Emergency (F.D.P.), Department of Neurology and Comprehensive Stroke Center (D.S.L., L.S., L.R., M.V.-S., J.L.S.), Neurovascular Imaging Research Core (D.S.L.), and Department of Biomathematics (J.G.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, University of Southern California, Los Angeles (N.S., M.-K.T.); Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.J.S.); Department of Emergency Medicine, Keck School of Medicine of the University of Southern California and Los Angeles Fire Department (M.E.); Los Angeles County Department of Public Health, CA (F.D.P.); National Institutes of Health, National Institutes of Neurological Disorders and Stroke, Bethesda, MD (R.C.); and School of Medicine, Stanford University, Palo Alto, CA (S.H.). jsaver@mednet.ucla.edu.
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Saver
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000488:Allied Health Personnel / Q000592:standards*; D002140:California / Q000453:epidemiology; D004632:Emergency Medical Services / Q000379:methods / Q000592:standards*; D004634:Emergency Medical Technicians / Q000592:standards; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D020521:Stroke / Q000175:diagnosis* / Q000453:epidemiology*
keywords: Los Angeles Motor Scale; field validation; paramedic assessment; prehospital stroke scale; stroke