Review for 10.1186/s12876-022-02364-0 (2022)

Title: A self-assessment tool for predicting discomfort and tolerance in Chinese patients
undergoing esophagogastroduodenoscopy
Version: 2 Date: 28 Dec 2021
Reviewer's report:
In their comprehensive  study Ou et al.  developed and validated a self-assessment prediction
tool for  discomfort and tolerance in Chinese patients undergoing esophagogastroduodenoscopy
(EGD).
Here, the authors recruited 1522 patients undergoing routine diagnostic EGD without sedation
and evaluated discomfort and tolerance with a 5-point visual analogue scale. Further, they
developed logistic regression predictive models based on the first 2/3 of participants, and
evaluated the calibration and discrimination of the models in the later 1/3 of patients (of the
same cohort).
The predictive factors in the model for discomfort included sex, education, expected level of
discomfort, and anxiety before endoscopy. The model for tolerance included income, expected
level of discomfort, and anxiety before endoscopy.
The authors found that 30.2% and 23.0% participants reported severe discomfort or poor
tolerance to EGD, respectively.
The authors conclude that they could develop and temporally validated two tools for predicting
discomfort and tolerance to unsedated EGD based on readily available data.
Overall, the present study is an interesting investigation on a very large study cohort.
As EGD is a common endoscopic examination, it is important to identify patients at risk who
require special attention.
However, while the study contains methodologically interesting aspects, it is not entirely clear
to the reviewer what benefit the study results have for everyday clinical practice.
Before a publication of the mansucript should be considered, the manuscript should be
thoroughly revised and the following aspects should be adequately addressed.
Introduction:
The authors provide a good introduction into the topic.
Methods:
What does upper second-class hospital mean? Please address.
Results:
The mean age of the cohort is surprisingly young at around 37.8.
From the reviewer's point of view, it would be  important to implement an overview of the
reasons for the  EGD examinations ?
( e.g.  reflux, dysphagia, hema emesis, pain, routine check up et cetera).
The respective indications for the examinations should be implemented either separately or in
the baseline characteristics table.
From the reviewer's point of view, it seems possible that people with EGD indications due to
severe symptoms perceive the examinations differently than patients with only mild symptoms.
How do the authors take this aspect into account in their predictive analysis?
Discussion:
Within their discussion, the authors state the following:
"...these models can be directly and conveniently used by patients and clinicians."
What is meant by this? An outlook should be implemented here.
Should all patients in the future be routinely evaluated for discomfort and tolerance, and then a
decision made as to whether or not to perform an EGD with or without sedation ?
Within the discussion, the authors also state:
"The associations were reasonable as both anxiety before EGD and the outcomes were closely
related to the emotional status of patients."
What should be the practical consequences of this observation in clinical practice? How can
anxiety be reduced?
Here, the authors discuss oral midazolam, music, and written educational material.
Which is the most promising approach? Does studies comparing different apporaches exist ?
The limitations are described comprehensively. From the reviewer's point of view, the greatest
weakness of the study is that no validation took place on an external cohort, which the authors
address.