title: Rapid antigen group A streptococcus test to diagnose pharyngitis: a systematic review and meta-analysis.
abstract: BACKGROUND
  Pharyngitis management guidelines include estimates of the test characteristics of rapid antigen streptococcus tests (RAST) using a non-systematic approach.
  
  
  OBJECTIVE
  To examine the sensitivity and specificity, and sources of variability, of RAST for diagnosing group A streptococcal (GAS) pharyngitis.
  
  
  METHODS
  MEDLINE, Cochrane Reviews, Centre for Reviews and Dissemination, Scopus, SciELO, CINAHL, guidelines, 2000-2012.
  
  
  METHODS
  Culture as reference standard, all languages.
  
  
  METHODS
  Study characteristics, quality.
  
  
  METHODS
  Sensitivity, specificity.
  
  
  RESULTS
  We included 59 studies encompassing 55,766 patients. Forty three studies (18,464 patients) fulfilled the higher quality definition (at least 50 patients, prospective data collection, and no significant biases) and 16 (35,634 patients) did not. For the higher quality immunochromatographic methods in children (10,325 patients), heterogeneity was high for sensitivity (inconsistency [I(2)] 88%) and specificity (I(2) 86%). For enzyme immunoassay in children (342 patients), the pooled sensitivity was 86% (95% CI, 79-92%) and the pooled specificity was 92% (95% CI, 88-95%). For the higher quality immunochromatographic methods in the adult population (1,216 patients), the pooled sensitivity was 91% (95% CI, 87 to 94%) and the pooled specificity was 93% (95% CI, 92 to 95%); however, heterogeneity was modest for sensitivity (I(2) 61%) and specificity (I(2) 72%). For enzyme immunoassay in the adult population (333 patients), the pooled sensitivity was 86% (95% CI, 81-91%) and the pooled specificity was 97% (95% CI, 96 to 99%); however, heterogeneity was high for sensitivity and specificity (both, I(2) 88%).
  
  
  CONCLUSIONS
  RAST immunochromatographic methods appear to be very sensitive and highly specific to diagnose group A streptococcal pharyngitis among adults but not in children. We could not identify sources of variability among higher quality studies. The present systematic review provides the best evidence for the wide range of sensitivity included in current guidelines.
authors.affiliation: Walter Reed National Military Medical Center, Bethesda, Maryland, United States of America.
authors.forename: Emily H
authors.initials: EH
authors.lastname: Stewart
authors.affiliation: University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Brian
authors.initials: B
authors.lastname: Davis
authors.affiliation: The University of Alabama at Birmingham, Huntsville Campus, Huntsville, Alabama, United States of America.
authors.forename: B Lee
authors.initials: BL
authors.lastname: Clemans-Taylor
authors.affiliation: University of Vermont, Burlington, Vermont, United States of America.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Littenberg
authors.affiliation: University of Alabama at Birmingham, Birmingham, Alabama, United States of America; Birmingham Veterans Affairs Medical Center and Veterans Affairs Quality Scholar Program, Birmingham, Alabama, United States of America.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Estrada
authors.affiliation: The University of Alabama at Birmingham, Huntsville Campus, Huntsville, Alabama, United States of America.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Centor
mesh_terms: D002846:Chromatography, Affinity / Q000191:economics / Q000379:methods*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000191:economics / Q000379:methods*; D010612:Pharyngitis / Q000175:diagnosis* / Q000382:microbiology*; D012680:Sensitivity and Specificity; D013290:Streptococcal Infections / Q000175:diagnosis* / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000302:isolation & purification*