Review for 10.1186/s12876-017-0667-9 (2017)

Reviewer ’s report  
 
Title: The diagnostic value of pepsin detection in saliva for gastro -esophageal reflux disease: a 
preliminary study from China  
 
Version: 0 Date: 24 May 2017  
 
Reviewer: YoenYoung Chuah  
 
Reviewer's report:  
 
Du and colleagues submitted their work entitled "The diagnostic value of pepsin detection in 
saliva for gast ro-esophageal reflux disease: a preliminary study from China" to the BMC 
Gastroenterolgy. This study aimed to determine the diagnostic value of salivary pepsin detection 
for GERD and concluded that salivary pepsin test had moderate diagnostic value for GER D. It 
may be a promising tool to replace the use of currently invasive tools with advantages of non -
invasive, easy to perform and cost effective.  
This paper is interesting and well -written but i have some concerns. This is the first study of the 
relation of pepsin level in saliva and its correlation to GERD in the Eastern countries. There 
seems to have correlation of pepsin positivity in GERD patients. However due to its high 
specificity of 88.3%, it may serve as a good tool to exclude those with GERD symp toms who are 
either inappropriate or unwilling to undertake upper gastrointestinal surveillance. One of the 
weak point of this study is the disproportion number in both groups, smaller number in healthy 
asymptomatic group. It will be better to recruit more  number in healthy asymptomatic group to 
make the data more convincing as like the study from Hayat et al.  
 
Comments:  
1. As you have mentioned that only small number of healthy asymptomatic subjects were 
enrolled if compared to GERD group in limitation of your study. Will this lead to bias? And 
how do youcorrect this bias?  
2. In Page 13, the citation of "In the study by SaritasYuksel [43], "it should be reference [42], 
please revise  
3. How was the conclusion of moderate diagnostic value for GERD be reached? It is because of 
moderate positivity in correlation to DeMeester score in Table 6. How does it show 
promising role in its moderate degree of diagnostic rate to replace other invasiv e tools.  
4. In your study, the Sensitivity rate is 73% and specificity 88.3% at the cut off value of 
76ng/ml; And the most similar study by Hayat et al with the sensitivity 78.6% and specificity 
64.9% at cut off value of 237 ng/ml (hypersensitivity esophagu s group) and 121 
ng/ml(GERD group) of Pepsin level. Yet I have not seen any data from Hayat et al showing 
the cut off value 203ng/ml on page 14 line 17. Can you show where does it come from?  
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 t o the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
No 
 
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 manusc ript: 
 
Acceptable  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an  
organisation that may in any way gain or lose financially from the publication of this  
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financially from the publication of this  manuscript, either now or in the future?  
 
3. Do you hold or are you currently applying for any patents relating to the content of the  
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization that 
holds  or has applied f or patents relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
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below.  If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests  
 
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