Review for 10.1186/s12876-020-01557-9 (2020)

Reviewer’s report
Title: 
Analysis of gastroscopy results among healthy people undergoing a
medical checkup: A retrospective study
Version: 
0 
Date: 
20 May 2020
Reviewer: 
Ian Beales
Reviewer's report:
The authors have provided data on the results of endoscopic examination of
apparently healthy people. The results are potentially of interest in that they give
is an insight into the prevalence of findings in asymptomatic people. Of course
endoscopy is usually limited to symptomatic patients, so further insights into
disease and abnormality prevalence are welcome. However there are several
issues with the presentation and reporting of the study that deserve further
comments, otherwise it is very difficult to draw any useful conclusions.
Major points.
1. Throughout the paper, including the abstract it would be preferable to
distinguish "endoscopic findings" from "disease." It is difficult to argue that a
finding in 95% of an asymptomatic population is a disease. The endoscopic
findings of both "gastritis" and "duodenitis" are notoriously unreliable as
predictors of significant disease and whilst they may well be true endoscopic
appearances, it is unclear whether they are really diseases.
2. The abstract should contain more definitive data on the important prevalence
data. Currently the abstract is too vague.
3. More detail is required on patient recruitment and flow. How exactly did
subjects get into this programme? Where they all volunteers, self-referrals? In
which case is this a potential source of bias, perhaps those actually with
symptoms were more likely to volunteer? This is seen in other screening
programmes. How do the authors know these subjects were asymptomatic? How
rigorous was the screening procedure? Please provide the exact criteria for
inclusion? it would seem that those with symptoms were excluded from the
study but presumably they also had an endoscopy? It would be very informative
to learn of the distribution of disease / findings in that group? Was it different
from the asymptomatic group? The background prevalence of smoking, use of
NSAIDs and other medications and previous endoscopy are all relevant data and
should be included.
4. The reported prevalence of disease is apparently very high. To place this in
context some more information about the research site (eg is this a primary care
unit or a tertiary care gastroenterology unit?). What about the demographics of
the surrounding population?
5. There should be some more details on the endoscopy procedure. Equipment
used, sedation etc. Was there a specific protocol for biopsies (this and the H
pylori screening seems rather hit and miss)? What, if any quality control was
applied to the reporting and endoscopy, such as central review of findings etc? It
would be helpful to know the definitions of the diseases used in this study. For
example either no subjects had erosions (which seems unlikely) but were these
classified into ulcers or gastritis? Additionally are there possible cultural or
financial issues which may have influenced the reporting of findings? I just
wonder as in other insurance-based systems, it has been reported that an
increased number of diagnoses and diagnostic codes are generated. In some
systems a single fleck of erythema in the gastric antrum would be regarded as
normal, in others it would be diagnosed with gastritis.
6. The first paragraph on page 3 (lines 1-19) is not particularly evidenced based.
Whilst physical examination is a traditional part of the medical encounter,
accumulating evidence shows the utility, especially in the asymptomatic is very
low. At the same time, most data (L 36) show that significant upper GI disease
increasing in prevalence with increasing age and even in symptomatic patients
the overall yield of clinically significant disease is low. Hence the move towards
non-invasive screening and avoiding endoscopy in younger patients. Whilst
clearly this is population and geography dependant, this rather contradicts lines
22-46 on page 3.
7. Page 4, line 7, what is an electronic gastroscopy?
8. A retrospective study like this may not require individual patient's consent but
it does require some institutional governance oversight concerning the use of
data. This should be addressed.
9. In the results when the authors consider gastritis, are they talking about
endoscopic or pathological gastritis? The definition of mild gastritis is very
vague, how many nuetrophils in the lamina propria are required? one or two or
how many?
10. Whilst the reported high-prevalnece of gastropathy, epsecially with a
relatively low prevalnce of H pylori is striking, the more important issue when
considering the role of screening is whether significant pre-malignant disease
was detected? The authors have not included any data on atrophic gastritis or
intestinal metaplasia? This would be very ineresting. At the same time, around
the world there is much debate about the accuarcy of endoscopic diagnosis of
these premalignany lesions and the authors may well actually have the data to
further inform these discussions.
11. Page 8 line 29. What does detection rate mean here? The rate of peptic ulcer
in those with H pylori infection or the rate of H pylori in those with peptic
ulcers? Overall it would be helpful if the authors provided the distributon of
findings clearly defined by H pylori-status.
12. I accept that the international nomeclature of gastric polyps is somewhat
controversial. However I do think many readers will be confused by the terms
used here. The generally accepted terms are fundc glandular, hyperplastic and
adenomatous polyps (with a 
few much rarer causes). It would be helpful if the
authors defied their polyps in such terms.
13. In table 1, what gastric rention mean? what does maga-esophagus mean? Is it
possible to use more clear diagnostic terminology? The prevalnce of glycogenic
acanthosis is remarkaly low, certainly conpared to studies in western
populations, presumably this is under-reporting? The absence of any cases of
cervical inlet patch is also striking given that many studies suggest a prevance of
2-10%. Do the authors feel that this is failure of detection or genuine absence in
this population?
14. Tables 2,3, 4 and 5 are hard to read. These data would seem to be easily
represented in graphical terms which may be prefrable. The presentation of the
distribution of polyps is also very confusing in the lower part of table 3. It would
be preferable to use the same age-bands as used in the top part of table 3. Does
table 6 add anything to the paper? The overal numbers in each group are small
and there are already lots of published data on the topographical distribution of
gastic polyps and are the current data and different?
Are the methods appropriate and well described?
If not, please specify what is required in your comments to the authors.
No
Does the work include the necessary controls?
If not, please specify which controls are required in your comments to the
authors.
Unable to assess
Are the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
Unable to assess
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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