Reviewer's report
Title:Frequency Format Diagram and Probability Chart for Breast Cancer Risk
Communication: a Prospective, Randomized Trial
Version: 1Date:18 April 2008
Reviewer: Phyllis Butow
Reviewer's report:
Review
This was a nicely written paper with a careful design, adequate sample size and
thoughtful hypotheses exploring optimal formats of risk presentation to those at
high risk of breast cancer. I have only a few suggestions:
• Major Compulsory Revisions
I feel that understanding of the results would be very much enhanced if the two
figures showing risk perception were altered. Since there were no baseline
differences between the groups, Figure 1 could show the numbers within each
risk category, and the numbers guessing that correctly and incorrectly pre and
post consultation.
The 2nd figure, showing only post-consultation risk perception (correct and
incorrect) could directly compare the bargraph and the bargraph plus 100 person
diagram groups, allowing the reader to much more easily assess these
differences. The number of people in each risk category could be reported in the
legend, or below each pair of bars.
• The authors have neglected to cite a major study in this area:
Feldman-Stewart, D., Kocovski, N., McConnell, B.A., Brundage, M.D. &
Mackillop, W.J. (2000b). Perception of quantitative information for treatment
decisions. Medical
Decision Making, 20, 228-238.
Feldman et al compared the perception of quantitative information (as measured
by accuracy and response speed) in choice and estimate tasks across six
different presentation formats: pie charts, vertical bars, horizontal bars, numbers,
systematic ovals (pictographs with icons highlighted in a systematic manner) and
random ovals (pictographs with icons highlighted randomly). For making a choice
(a simple, ‘gross-level’ comparative task), where the subjects were asked to
identify which amount was bigger or smaller, systematic ovals, vertical bars,
horizontal bars and numbers were equally well perceived; pie charts and random
ovals caused slower and less accurate performances. For estimating differences
between risks or the magnitude of a single risk (a more detailed task), numbers
led to the most accurate estimates, followed by systematic ovals. The other four
formats caused less accurate performances.
Similarly, other papers have explored relevant issues, which should be
incorporated into the literature review and Discussion: e.g.
Fuller, R., Dudley, N. & Blacktop, J. (2002). How informed is consent?
Understanding of pictorial and verbal probability information by medical
inpatients. Postgraduate
Medical Journal, 78, 543-544.
Fuller, R., Dudley, N. & Blacktop, J. (2001). Risk communication and older
people –
understanding of probability and risk information by medical impatient aged 75
years
and older. Age Ageing, 30, 473-5.
Timmermans, D., Molewijk, B., Stiggelbout, A. & Kievit, J. (2004). Different
formats for communicating surgical risk to patients and the effect on choice of
treatment. Patient Education and Counseling, 54, 25-263.
Given that randomized was stratified by age, I wondered if there were age
effects?
Level of interest: An article of importance in its field
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests