Review for 10.1186/s12876-016-0519-z (2016)

Reviewer ’s report  
 
Title: Endoscopic ultrasonography with fine -needle aspiration for histological diagnosis of solid 
pancreatic masses: A meta -analysis of diagnostic accuracy studies  
 
 
Version: 0 Date: 25 Jan 2016  
 
 
Reviewer: Stavros  Antoniou  
 
Reviewer's report:  
 
This is an interesting systematic review and meta -analysis of diagnostic accuracy studies on 
endoscopic ultrasonography for pancreatic masses. The authors have performed a meticulous 
work, the presentation of the article is clear and concise a nd the study delivers a clear message to 
the reader.  
I have several comments, which might improve the quality of this work. Specific attention 
should be given to the quality assessment of the included reports.  
1. Title: The title might be more informative if it would report on the type of the meta -analysis; 
i.e. a meta -analysis of diagnostic accuracy studies.  
2. Materials and methods: Identification of studies: Can you please confirm that all terms listed 
are MeSH terms?  
3. Materials and methods: Eligibilit y criteria: "or a follow -up period of at least 6 months"; How 
was it judged at follow up whether the diagnosis was cancer, if a histological diagnosis was not 
obtained?  
4. Materials and methods: Eligibility criteria: "We excluded  studies with limited data ": needs to 
be specified.  
5. Materials and methods: Study quality assessment; The quality assessment tool needs to be 
referenced. Details on the tool need to be provided: is it validated?  
6. Materials and methods: Statistical analysis: "to computer sensiti vity" needs to be corrected to 
"to compute sensitivity"  
7. Results and discussion: No data on quality assessment are provided.  
8. Results and discussion: The exclusion of non -English articles needs to be commented as a 
limitation and potential source of la nguage bias.  
9. EUS -FNA techniques: Reporting of the size range of the pancreatic mass and the median 
tumor size is unclear. Did the authors calculate the median size from the raw data of each study? 
Was the range 0.8 -14 cm or 0.6 -10 cm?  
10. Safety of EUS -FNA: Although not included in the aims of this study, it would be extremely 
interesting to calculate the weighted pooled procedure -related morbidity of EUS -FNA. this is 
relevant to the scope of this review, since the reader needs to be informed not only on  the 
expected benefit, but also the associated risk.  
11. Pooled results: "summary sensitivity and specificity"; the terms pooled sensitivity and 
specificity may be preferable, also to be consistent with the figures.  
12. Pooled results: "diagnostic odd rati o" needs to be corrected to "diagnostic odds ratio".  
13. Sources of heterogeneity: "The possible sources of heterogeneity in our study included 
publication bias, study design and methodological quality. None of the analyzed variables 
showed statistical sig nificance."; the authors need to be more specific: how were the variables 
divided? for example, prospective/retrospective studies; high/low methodological quality, and 
how it was measured. How was publication bias assessed?  
14. Discussion: "Thus, an import ant strength of our meta -analysis is that it included studies 
performed by operators with different expertise from different centers in different countries."; 
Very good point. Did the authors record the level of experience of EUS operators across studies? 
This factor is most probably poorly reported, but in this case it would be worth mentioning that 
the level of experience should be reported in future studies.  
15. Discussion: "In addition, the diagnostic accuracy of EUS -FNA for pancreatic masses may 
also b e affected by tumor size and location, needle size, and the presence of an on -site 
cytopathologist"; What is the hypothesis behind the presumed increased accuracy of EUS -FNA 
in the presence of an on -site cytopathologist?  
16. Discussion: "In the present stu dy, only 2.2% (39/1760) of cases developed complications"; It 
is recommended to calculate the weighted pooled morbidity, rather than the pooled morbidity.  
17. Conclusion: "Compared with other diagnostic modalities, EUS -FNA is safer and has many 
advantages,  such as the ability to detect a tiny lesion and obtain much more diagnostic 
information."; Since this last sentence is not based upon data of this analysis, it may be suggested 
either to skip it and replace it (for example, report on the robustness of the  evidence provided 
instead), or to be less emphatic (for example: EUS -FNA may be safer and probably provides 
advantages over other modalities, such as...).  
 
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 supporte d 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 spe cify 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:  
 
Acceptable  
 
Declaration of competing interests  
Please comp lete 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 t his 
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose  
financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold or are you currently apply ing 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 for 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?  
 
If you can answer no to all of the above, write 'I declare that I have no competing interests' 
below.  If your reply is y es to any, please give details below.  
 
I declare that I have no competing interests . 
 
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