title: Validation of a Short, 3-Item Version of the Subjective Numeracy Scale.
abstract: Efficiency in scale design reduces respondent burden. A brief but reliable measure of numeracy may provide a useful research tool eligible for integration into large epidemiological studies or clinical trials. Our goal was to validate a 3-item version of the Subjective Numeracy Scale (SNS-3).
  
  
  
  We examined 7 separate cross-sectional data sets: patients in the emergency department (n = 208), clinic (n = 205), and hospital (n = 460; n = 2053) and patients with chronic kidney disease (n = 147), with diabetes (n = 318), and on hemodialysis (n = 143).
  
  
  
  Internal reliability of the SNS-3 was assessed with Cronbach's α. Criterion validity was determined by nonparametric correlations of the SNS-3 with SNS-8 and other measures of numeracy; construct validity was determined by correlations with measures of health literacy and education.
  
  
  
  The SNS-3 had good internal reliability (median Cronbach's α = 0.78) and correlated highly with the full SNS (median ρ = 0.91). The SNS-3 was significantly correlated with other measures of numeracy (e.g., median ρ = 0.57 with the Wide Range Achievement Test 4), health literacy (e.g., median ρ = 0.35 with the Shortened Test of Functional Health Literacy in Adults), and education (median ρ = 0.41), providing good evidence of criterion and construct validity.
  
  
  
  The SNS-3 is sufficiently reliable and valid to be used as a measure of subjective numeracy.
authors: Department of Emergency Medicine (CDM), Vanderbilt University, Nashville, TN, USA
authors: Candace D
authors: CD
authors: McNaughton
authors: Department of Internal Medicine (KLC, SK, RLR), Vanderbilt University, Nashville, TN, USA|Vanderbilt Center for Kidney Disease (KLC), Vanderbilt University, Nashville, TN, USA
authors: Kerri L
authors: KL
authors: Cavanaugh
authors: Department of Internal Medicine (KLC, SK, RLR), Vanderbilt University, Nashville, TN, USA
authors: Sunil
authors: S
authors: Kripalani
authors: Department of Internal Medicine (KLC, SK, RLR), Vanderbilt University, Nashville, TN, USA
authors: Russell L
authors: RL
authors: Rothman
authors: School of Nursing (KAW), Vanderbilt University, Nashville, TN, USA.
authors: Kenneth A
authors: KA
authors: Wallston
mesh_terms: D000046:Academic Medical Centers; D054058:Acute Coronary Syndrome; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus; D004521:Educational Measurement / Q000379:methods* / Q000592:standards*; D004636:Emergency Service, Hospital; D057220:Health Literacy / Q000379:methods* / Q000592:standards*; D006761:Hospitals; D006801:Humans; D006973:Hypertension; D008433:Mathematics; D011594:Psychometrics; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic; D015203:Reproducibility of Results
keywords: health literacy; numeracy; psychometric models; scale development