Review for 10.1186/1471-230X-14-121 (2014)

Reviewer's report
Title:Fecal Lactoferrin in Discriminating Inflammatory Bowel Disease from
Irritable Bowel Syndrome: A Diagnostic Meta-analysis
Version:1Date:3 March 2014
Reviewer: Paul Henderson
Reviewer's report:
Major Compulsory Revisions:
1. Other useful biomarkers (especially faecal biomarkers such as calprotectin)
should be mentioned briefly in the introduction.
2. Also MeSH headings are useful they are not always all-encompassing. Did the
authors use other keywords in their electronic search such as enteritis, ileitis etc?
3. Do the authors feel it is necessary to have a test of heterogeneity? As I
understand that the Cochrane review group do not find this a useful test in
studies of diagnostic accuracy?
4. Did the authors make any attempt to obtain thedata needed for the 2x2 tables
in the 4 studies that did not present the data in their paper? Did the authors
contacts the study team by email/letter - this should have been attempted if not.
5. The authors should highlight that the use of heathly volunteers is not
appropriate in tests of diagnostic accuracy as this is not a representative
population.
6. P6/L9 - what does "filtered" mean?
7. Where all the studies looking at the use of lactoferrin at diagnosis? or did
some of the studies look at those who had already had confirmed IBD etc - this
should be explicitly mentioned.
8. I understand that the Cochrane group suggest that although the QUADAS
system is most appropriate in this type of analysis, the sue of individual study
scores is not of use - this should be looked at by the authors.
9. When presenting statistics -should the AUC not be with 95% confidence
intervals, rather than standard error?
10. P9/L4 - obligatory involvement of the rectum is only reliable in adult patients
11. The number of articles excluded should be split up into the individual reasons
for each exclusion (e.g. Not at diagnosis=n, no endoscopic evaluation=n etc)
12. The authors do not mention a useful clinical cut-off value for FL to help guide
clinicians...
13. Was it possible o exclude the 4 studies that used healthy controls to give a
more representative sample? Could the authors of each study have been
contacted to try and achieve this?
14. Can the authors explain why different cut-off values were used in different
studies even though the assay was identical?
Minor Essential Revisions:
1. Although commendable, the manuscript should be proof read by a native
English language speaker.
2. IBD does not affect any part of the GI tract (P3/L1), this refers to Crohn's
disease only - this should be re-written
3. The first reference should be updated to a more recent, relevant review
4. A recent review on IBS should be given (P3/L4) to direct the reader to current
literature
5. P3/L7 - remains challengING
6. Could the authors provide more recent articles for references 3 and 4?
7. FL should be expanded at the first mention (P3/L18)
8. P4/L8 - eligible STUDIES (these are not trials)
9. Elder should be substituted for ADULT (e.g. P4/L14)
10. P4/L25 - was REferred...
Discretionary Revisions
1. The authors should consider restructuring the discussion, e.g. main findings of
their analysis, study strengths, study weaknesses, background of lactoferrin,
other biomarkers, clinical application, conclusions
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Needs some language corrections before being
published
Statistical review: Yes, and I have assessed the statistics in my report.
Declaration of competing interests:
I declare that I have no competing interests