Review for 10.1186/s12876-021-01677-w (2021)

Reviewer’s report
Title: 
Epidemiological Survey to Determine the Prevalence of
Cholecystolithiasis in Uyghur, Kazakh, and Han Ethnic Groups in the Xinjiang
Uyghur Autonomous Region of China- 
cross-sectional studies
Version: 
0 
Date: 
01 Apr 2020
Reviewer's report:
The paper describes a large screening study for cholecystolithiasis, with more
than 5000 residents participating. This may become a very cited paper as it
provides baseline data for the management of gallstone disease on the population
level. I am not convinced that it may provide a basis for prevention as suggested
in the abstract, but it improves our understanding of the gallstone disease since
the actual prevalence is poorly known. These data may provide the
"denominator" when assessing the impact of the disease on the population and
the actions taken to treat the disease.
Comments:
1. My greatest concern is the sampling process. Typical case sampling and
multistage stratified random sampling methods were used. Both techniques may
lead to selection bias. The uneven gender distribution (35.7% males and 64.3%
females) indicates that the sampling may have lead to a selection. Were all adult
members of each selected household invited? Could there have been a
confounding factor leading to a greater participation for residents with history of
gastrointestinal symptoms?
2. How were residents who had already undergone gallstone surgery treated in
the analyses?
3. How were residents of mixed ethnic background categorized?
4. Under 2.2.1 (Characteristics of subjects) it is stated that 5454/6024 met the
inclusion criteria. I assume they mean that 5454 agreed to participate in the
study. The authors should be congratulated for this high rate, it corroborates the
validity of the study.
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.
Yes
Are the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
Yes
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:
Acceptable
Declaration of competing interests
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