title: Using icon arrays to communicate medical risks: overcoming low numeracy.
abstract: OBJECTIVE
  Icon arrays have been suggested as a potentially promising format for communicating risks to patients-especially those with low numeracy skills-but experimental studies are lacking. This study investigates whether icon arrays increase accuracy of understanding medical risks, and whether they affect perceived seriousness of risks and helpfulness of treatments.
  
  
  METHODS
  Two experiments were conducted on samples of older adults (n = 59, 62 to 77 years of age) and university students (n = 112, 26 to 35 years of age).
  
  
  METHODS
  Accuracy of understanding risk reduction; perceived seriousness of risks; perceived helpfulness of treatments.
  
  
  RESULTS
  Icon arrays increased accuracy of both low- and high-numeracy people, even when transparent numerical representations were used. Risks presented via icon arrays were perceived as less serious than those presented numerically. With larger icon arrays (1,000 instead of 100 icons) risks were perceived more serious, and risk reduction larger.
  
  
  CONCLUSIONS
  Icon arrays are a promising way of communicating medical risks to a wide range of patient groups, including older adults with lower numeracy skills.
authors.affiliation: Center for Adaptive Behavior and Cognition, Max Planck Institute for Human Development, Berlin, Germany. galesic@mpib-berlin.mpg.de
authors.forename: Mirta
authors.initials: M
authors.lastname: Galesic
authors.forename: Rocio
authors.initials: R
authors.lastname: Garcia-Retamero
authors.forename: Gerd
authors.initials: G
authors.lastname: Gigerenzer
mesh_terms: D000328:Adult; D000368:Aged; D000924:Anticholesteremic Agents / Q000627:therapeutic use; D001161:Arteriosclerosis / Q000188:drug therapy; D001241:Aspirin / Q000627:therapeutic use; D001294:Attitude to Health; D003196:Computer Graphics; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000188:drug therapy; D008297:Male; D008403:Mass Screening / Q000523:psychology; D008433:Mathematics; D008875:Middle Aged; D009203:Myocardial Infarction / Q000517:prevention & control; D010353:Patient Education as Topic / Q000379:methods*; D011337:Probability Learning; D011340:Problem Solving; D040242:Risk Reduction Behavior; D020521:Stroke / Q000517:prevention & control; D013561:Symbolism
chemical_list: D000924:Anticholesteremic Agents; D001241:Aspirin