Title: Clinical application of capsule sponge testing in symptomatic reflux disease: a national
prospective cohort study
Version: 3 Date: 22 Aug 2024
Reviewer:  Sarah K. Thompson
Reviewer's report:
The authors present a retrospective cohort study evaluating the clinical utility of capsule sponge
testing in patients with reflux. I would like to commend the authors on an excellent study. Of
course, I have some questions and concerns but this is a great effort and a valuable addition to
the current literature on the topic.
1. Why is pregnancy a contraindication to capsule sponge testing? Similarly, why is
"oesophageal surgery" a contraindication - I can understand this for malignant oesophageal
surgery but many patients who have had a fundoplication for reflux still need ongoing
endoscopic surveillance.
2. How did the authors define "reflux"? This has not been elaborated. Were they just looking
at typical symptoms?
3. It is a little concerning that only 42% of the cohort were male. This goes against most other
studies looking at reflux and those at risk. Part of the problem might be the inclusion criteria.
It is well documented that many male patients have silent reflux. Perhaps the inclusion criteria
should have been expanded at the outset of the study to include referrals for male, obese, age
range 40-65, etc? Can the authors comment.
4. Clearly, it would have been ideal to follow on with endoscopy for all patients undergoing
capsule sponge testing. Then, it could be compared against the gold standard. This is a major
limitation of the study. Please comment on the decision not to follow on with endoscopy for
this study.
5. I am not sure I agree with a statement in the Discussion stating that endoscopy is not a
perfect test and that 14-24% of cancer cases are post-endoscopy. Can the authors comment on
whether they would follow on with another study designed to evaluate for the presence of missed
pathology.
6. No mention is made in the Discussion re. other technology which could be used to better
stratify patients who need an endoscopy for reflux disease. What about mucosal impedance, for
example?
Title: Clinical application of capsule sponge testing in symptomatic reflux disease: a national
prospective cohort study
Version: 3 Date: 22 Aug 2024
Reviewer:  Sarah K. Thompson
Reviewer's report:
The authors present a retrospective cohort study evaluating the clinical utility of capsule sponge
testing in patients with reflux. I would like to commend the authors on an excellent study. Of
course, I have some questions and concerns but this is a great effort and a valuable addition to
the current literature on the topic.
1. Why is pregnancy a contraindication to capsule sponge testing? Similarly, why is
"oesophageal surgery" a contraindication - I can understand this for malignant oesophageal
surgery but many patients who have had a fundoplication for reflux still need ongoing
endoscopic surveillance.
2. How did the authors define "reflux"? This has not been elaborated. Were they just looking
at typical symptoms?
3. It is a little concerning that only 42% of the cohort were male. This goes against most other
studies looking at reflux and those at risk. Part of the problem might be the inclusion criteria.
It is well documented that many male patients have silent reflux. Perhaps the inclusion criteria
should have been expanded at the outset of the study to include referrals for male, obese, age
range 40-65, etc? Can the authors comment.
4. Clearly, it would have been ideal to follow on with endoscopy for all patients undergoing
capsule sponge testing. Then, it could be compared against the gold standard. This is a major
limitation of the study. Please comment on the decision not to follow on with endoscopy for
this study.
5. I am not sure I agree with a statement in the Discussion stating that endoscopy is not a
perfect test and that 14-24% of cancer cases are post-endoscopy. Can the authors comment on
whether they would follow on with another study designed to evaluate for the presence of missed
pathology.
6. No mention is made in the Discussion re. other technology which could be used to better
stratify patients who need an endoscopy for reflux disease. What about mucosal impedance, for
example?
Please review this paper.
user
Title: Clinical application of capsule sponge testing in symptomatic reflux disease: a national
prospective cohort study
Version: 3 Date: 22 Aug 2024
Reviewer:  Sarah K. Thompson
Reviewer's report:
The authors present a retrospective cohort study evaluating the clinical utility of capsule sponge
testing in patients with reflux. I would like to commend the authors on an excellent study. Of
course, I have some questions and concerns but this is a great effort and a valuable addition to
the current literature on the topic.
1. Why is pregnancy a contraindication to capsule sponge testing? Similarly, why is
"oesophageal surgery" a contraindication - I can understand this for malignant oesophageal
surgery but many patients who have had a fundoplication for reflux still need ongoing
endoscopic surveillance.
2. How did the authors define "reflux"? This has not been elaborated. Were they just looking
at typical symptoms?
3. It is a little concerning that only 42% of the cohort were male. This goes against most other
studies looking at reflux and those at risk. Part of the problem might be the inclusion criteria.
It is well documented that many male patients have silent reflux. Perhaps the inclusion criteria
should have been expanded at the outset of the study to include referrals for male, obese, age
range 40-65, etc? Can the authors comment.
4. Clearly, it would have been ideal to follow on with endoscopy for all patients undergoing
capsule sponge testing. Then, it could be compared against the gold standard. This is a major
limitation of the study. Please comment on the decision not to follow on with endoscopy for
this study.
5. I am not sure I agree with a statement in the Discussion stating that endoscopy is not a
perfect test and that 14-24% of cancer cases are post-endoscopy. Can the authors comment on
whether they would follow on with another study designed to evaluate for the presence of missed
pathology.
6. No mention is made in the Discussion re. other technology which could be used to better
stratify patients who need an endoscopy for reflux disease. What about mucosal impedance, for
example?
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