Review for 10.1186/s12876-015-0253-y (2015)

Reviewer's report
Title:The Prevalence of Gastro-Esophageal Reflux Disease and Esophageal
Dysmotility in Chinese Patients with Idiopathic Pulmonary Fibrosis
Version:2Date:24 October 2014
Reviewer: Edoardo Savarino
Reviewer's report:
Summary and Comments
The article entitled "The Prevalence of Gastro-Esophageal Reflux Disease and
Esophageal Dysmotility in Chinese Patients with Idiopathic Pulmonary Fibrosis”
by Gao et al. is a prospective study designed to evaluate the prevalence of
GERD and esophageal motility disorders in 69 Chinese IPF patients by using
HiRM and impedance-pH monitoring. The main results of the investigation were:
1) GERD prevalence was higher among IPF patients; 2) IPF patients with GERD
had an increased prevalence of weak peristalsis, greater acid exposure
percentage, higher bolus exposure time and more episodes of distal and
proximal reflux than those without reflux; 3) symptoms presence alone were not
good predictor of the 37 presence of reflux due to poor sensitivity and specificity.
The main idea of the study is not original since previous studies have already
assessed this issue (Am J Respir Crit Care Med Vol 179. pp 408–413, 2009; Eur
Respir J 2013; 42: 1322–1331). In the latter investigations it has been shown as
patients with IPF or scleroderma with lung involvement presented less commonly
with typical reflux symptoms (heartburn and regurgitation) than patients without
IPF, higher esophageal acid exposure time, greater number of reflux episodes
(impedance-pH testing was used!) and a positive correlation between severity of
reflux with pulmonary fibrosis. Thus, it appears almost incredible that the authors
did not analysed them in order to compare their results with those observed
previously in Western population by using the same technique. This is a pity
because this study has also few points of strength (use of the state-of-the-art
techniques to assess both reflux disease and esophageal motility, the
prospective design and the number of patients enrolled with IPF) that make this
investigation, although only confirmatory of previous findings, relevant for the
topic (reflux in IPF).
Major Compulsory Revisions:
1. Methods. The period of wash-out PPI therapy before impedance-pH testing is
too short (at least 7 days are necessary for the stomach to restore is capability to
produce acid at pre-therapy level). Please, justify this decision and include them
among the limitations of the study.
2. Methods. There was no control group in this study. Please, comment on that
among the limitations of the study
3. Methods. Reference 11 is inappropriate since no normal values are provided
in that paper.
4. Methods. It is not clear which parameters have been considered for GERD +
and GERD -. Please, clarify on the methods when an IPF was positive for GERD
(i.e. abnormal acid exposure and/or abnomrla number of reflux episodes
and/or…….?)
5. Results. Data on PPI use among subjects have not been provided and
discussed. Please, add this crucial information
6. Discussion. Data on Sens, Spec, PPV and PNV of GERD symptoms should be
provided in the results and then explained and discussed in the Discussion
section
7. Data on bolus transit should be highlighted as they are unique of this study
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a statistician.
Declaration of competing interests:
I declare that I have no competing interests