Perceived risk of tamoxifen side effects: a study of the use of absolute frequencies or frequency bands, with or without verbal descriptors.
OBJECTIVE
To investigate the effectiveness of presenting medicine side effect risk information in different forms, including that proposed by UK guidelines [[1] Medicines and Healthcare products Regulatory Agency. Always read the leaflet-Getting the best information with every medicine. (Report of the Committee on Safety of Medicines Working Group on Patient Information). London: The Stationery Office, 2005.].


METHODS
134 Cancer Research UK (CRUK) website users were recruited via a 'pop-up'. Using a 2x2 factorial design, participants were randomly allocated to one of four conditions and asked to: imagine they had to take tamoxifen, estimate the risks of 4 side effects, and indicate a presentation mode preference.


RESULTS
Those presented with absolute frequencies demonstrated greater accuracy in estimating 2 of 4 side effects, and of any side effect occurring, than those presented with frequency bands. Those presented with combined descriptors were more accurate at estimating the risk of pulmonary embolism than those presented with numeric descriptors only.


CONCLUSIONS
Absolute frequencies outperform frequency bands when presenting side effect risk information. However, presenting such exact frequencies for every side effect may be much less digestible than all side effects listed under 5 frequency bands. Combined numerical and verbal descriptors may be better than numeric only descriptors when describing infrequent side effects.


CONCLUSIONS
Information about side effects should be presented in ways that patients prefer, and which result in most accurate risk estimates.
Knapp
Peter
P
School of Healthcare, University of Leeds, Leeds, UK. p.r.knapp@leeds.ac.uk
Gardner
Peter H
PH
Raynor
David K
DK
Woolf
Elizabeth
E
McMillan
Brian
B
D032882:Comprehension; D054626:Consumer Health Information; D004348:Drug Labeling; D005260:Female; D057220:Health Literacy; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D057240:Patient Preference; D012306:Risk; D018570:Risk Assessment; D013223:Statistics as Topic; D013629:Tamoxifen / Q000009:adverse effects*; D006113:United Kingdom
D013629:Tamoxifen