title: Symbols were superior to numbers for presenting strength of recommendations to health care consumers: a randomized trial.
abstract: OBJECTIVE
  To compare health care consumers' understanding, evaluations, and preferences for symbols vs. numbers and letters for the representation of strength of recommendations (SOR) and quality of evidence (QOE).
  
  
  METHODS
  Questionnaire study in a randomized controlled design in the setting of a community health education program.
  
  
  RESULTS
  Eighty-four participants completed the questionnaire. For the presentation of the SOR, participants had better objective understanding of symbols than numbers (74% vs. 14%, P<0.001). They also scored symbols positively, and numbers negatively for ease of understanding (mean difference [md]=1.5, P=0.001), clearness and conciseness (md=1.5, P<0.001), and conveyance of the degree of uncertainty (md=0.7, P=0.092). About half (48%) preferred symbols over numbers. For the presentation of the QOE, objective understanding of symbols and letters was similar (91% vs. 95%, P=0.509). Participants scored both symbols and letters positively; the scores for symbols were however lower for ease of understanding (md=-0.7, P=0.019), clearness and conciseness (md=-0.6, P=0.051), and conveyance of the QOE (md=-0.4, P=0.24).
  
  
  CONCLUSIONS
  Symbols were superior to numbers for the presentation of the SOR. Objective understanding was high for both symbols and letters for the presentation of the QOE, but letters conveyed the QOE better than symbols.
authors.affiliation: Department of Medicine, University at Buffalo, NY, USA.
authors.forename: Elie A
authors.initials: EA
authors.lastname: Akl
authors.forename: Nancy
authors.initials: N
authors.lastname: Maroun
authors.forename: Gordon
authors.initials: G
authors.lastname: Guyatt
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Oxman
authors.forename: Pablo
authors.initials: P
authors.lastname: Alonso-Coello
authors.forename: Gunn E
authors.initials: GE
authors.lastname: Vist
authors.forename: P J
authors.initials: PJ
authors.lastname: Devereaux
authors.forename: Victor M
authors.initials: VM
authors.lastname: Montori
authors.forename: Holger J
authors.initials: HJ
authors.lastname: Schünemann
mesh_terms: D000328:Adult; D000368:Aged; D003142:Communication; D003153:Community Health Services / Q000379:methods; D032882:Comprehension; D003258:Consumer Behavior; D019317:Evidence-Based Medicine; D005260:Female; D006266:Health Education / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015397:Program Evaluation; D011795:Surveys and Questionnaires