title: Explanations for side effect aversion in preventive medical treatment decisions.
abstract: OBJECTIVE
  Many laypeople demonstrate excessive sensitivity to negative side effects of medical treatments, which may lead them to refuse beneficial therapies. This Internet-based experiment investigated three possible explanations for such "side effect aversion." One was derived from mental accounting, one examined the mere presence of a side effect, and one focused on computational difficulties.
  
  
  METHODS
  Participants (N = 5,379) were presented with a hypothetical cancer preventive treatment situation that was or was not accompanied by one or two small side effects. The side effects were either beneficial or harmful. In all conditions, the net absolute risk reduction associated with the treatment was 15%.
  
  
  METHODS
  Participants indicated their willingness to accept treatment and their perceptions of the treatment's effects on their overall cancer risk.
  
  
  RESULTS
  Data were consistent only with the "mere presence" explanation of side effect aversion, the idea that side effects act as a strong negative cue that directly affects treatment appraisal. The number of negative side effects did not influence treatment willingness.
  
  
  CONCLUSIONS
  Side effect aversion is a challenge to informed decision making. Specific mechanisms that produce side effect aversion should be identified.
authors.affiliation: Cancer Prevention Fellowship Program, Office of Preventive Oncology, National Cancer Institute, Bethesda, MD 20892-7365, USA. erika.a.waters@gmail.com
authors.forename: Erika A
authors.initials: EA
authors.lastname: Waters
authors.forename: Neil D
authors.initials: ND
authors.lastname: Weinstein
authors.forename: Graham A
authors.initials: GA
authors.lastname: Colditz
authors.forename: Karen
authors.initials: K
authors.lastname: Emmons
mesh_terms: D000293:Adolescent; D000328:Adult; D000970:Antineoplastic Agents / Q000009:adverse effects* / Q000627:therapeutic use*; D003657:Decision Making; D005260:Female; D006306:Health Surveys; D006801:Humans; D020407:Internet; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000517:prevention & control* / Q000523:psychology*; D010342:Patient Acceptance of Health Care / Q000523:psychology*; D018570:Risk Assessment; D011795:Surveys and Questionnaires; D016312:Treatment Refusal / Q000523:psychology; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents