title: The effect of numeracy on the comprehension of information about medicines in users of a patient information website.
abstract: OBJECTIVE
  To investigate the relationship between numeracy and the accuracy of side effect risk estimation following the presentation of information about a medicine via the Cancer Research UK (CR-UK) patient information website.
  
  
  METHODS
  591 website users were presented with information in different formats about the risks of side effects from taking tamoxifen. Participants estimated the risk of each side effect, provided other subjective ratings about the information and completed a numeracy task.
  
  
  RESULTS
  Regardless of presentation format, numeracy was correlated with the accuracy of three side effect risk estimates. People with cancer and tamoxifen users showed stronger correlations for all side effect estimates. In addition, numeracy was positively related to the perceived influence of the information on the decision to take the medicine and was negatively related to ratings of satisfaction with the information.
  
  
  CONCLUSIONS
  People with a lower numeracy level make larger errors in interpreting medicines side effect risk information.
  
  
  CONCLUSIONS
  Pharmacists, other health professionals and patient information websites should ensure they provide clear explanations of risk, particularly to people with low numeracy, and assess their understanding of those explanations. Future research into risk communication should take account of numeracy level, to investigate the impact of different formats.
authors.affiliation: Institute of Psychological Sciences, University of Leeds, Leeds, UK. p.h.gardner@leeds.ac.uk
authors.forename: Peter H
authors.initials: PH
authors.lastname: Gardner
authors.forename: Brian
authors.initials: B
authors.lastname: McMillan
authors.forename: David K
authors.initials: DK
authors.lastname: Raynor
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Woolf
authors.forename: Peter
authors.initials: P
authors.lastname: Knapp
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects; D032882:Comprehension; D054626:Consumer Health Information; D004346:Drug Information Services / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D020407:Internet; D008297:Male; D008433:Mathematics; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy; D010465:Perception; D012306:Risk; D018570:Risk Assessment / Q000706:statistics & numerical data; D013629:Tamoxifen / Q000009:adverse effects; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents; D013629:Tamoxifen