Reviewer’s report
Title: Correlates of regret with treatment decision-making among Japanese women with breast cancer:  
Results of an Internet-based cross-sectional survey
Version: 0 Date: 29 Mar 2019
Reviewer: Ann Hamilton
Reviewer's report:
This is an interesting paper on the factors associated with regret in treatment decision making among  
Japanese women with early stage breast cancer. It is based on 467 women recruited through the  
internet, thus the representativeness of the sample is unknown. Aside from that limitation, there are  
some errors that need correcting and some additional data analyses that would enhance the value of the  
study.
Although reported previously, it would be helpful to provide more information on how these women  
were recruited and if any effort was made to assess representativeness of the sample.
Specifically the title of Table 2 should read 'Univariate and Multivariable OR's associated with having  
regret in treatment decision making process'. The title currently reads 'having no regret', which is  
incorrect based on the direction of the OR's and how they are interpreted in the results.
Regarding the preferred and perceived decision making style questions, it would be of interest to see a  
cross  tab  of the  two to  understand  how  decisional  incongruence  is  distributed.  For example  the  
difference between 'active' vs. 'collaborative' may not be that large since both could include patient and  
physician  involvement  according  to the definitions  provided. Perhaps  most  of the discordance  is  
between active vs. passive. 
Additional analyses should be included regarded the treatment decision to receive BCS vs. TM. Women  
receiving a TM had the largest AOR associated with regret. This would seem to be the most regrettable  
experience--which type of surgery they choose. It might be of interest to look at some of the tables  
stratified by type of surgery. In other words, decisional incongruence may play a stronger role related to  
regret for those who received a TM vs. those who received BCS. Also Table 4 may provide some  
additional insights if stratified by surgery type. For example influence on sex life may be especially  
important for those choosing BCS vs. TM. These insights would provide more information to women  
who are faced with making this choice in the future.
With regard to the limitation related to self-reported information, how were the questions asked about  
the type of surgery received? Were these validated questions?
Are the methods appropriate and well described?
If not, please specify what is required in your comments to the authors.
Yes
Does the work include the necessary controls?
If not, please specify which controls are required in your comments to the authors.
Yes
Are the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
Yes
Are you able to assess any statistics in the manuscript or would you recommend an additional  
statistical review?
If  an  additional  statistical  review  is  recommended,  please  specify  what  aspects  require  further  
assessment in your comments to the editors.
I am able to assess the statistics
Quality of written English
Please indicate the quality of language in the manuscript:
Needs some language corrections before being published
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