Review for 10.1186/s12876-020-1166-y (2020)

Reviewer’s report
Title: Associations between disease activity, social support and health-related quality of life in
patients with inflammatory bowel diseases: the mediating role of psychological symptoms
Version: 0 Date: 04 Jun 2019
Reviewer: Lea Ann Chen
Reviewer's report:
The study is a single-center, cross-sectional evaluation of various metrics of psychological symptoms,
social support, IBD activity and health-care related quality of life at an institution in China. The
underlying goal was to determine if, and to what extent, mental health (as represented by the Hospital
Depression and Anxiety Scale) mediated the effects of disease activity and/or social support on IBD-
related quality of life (as measured by the IBDQ). The authors found that increased disease activity
correlated with worsened QoL and that this effect was partially mediated by mental health scores. They
also found a positive correlation between social support and QoL, which was completed mediated by
mental health scores. 
The clinical relevance for developing a conceptual model of social support, psychological symptoms,
disease activity and HrQoL is heavily dependent on whether modulation of a mediating variable
actually impacts disease outcome, which seems beyond the scope of the work submitted. Thus while
the applicability of the study results may be limited, there is relatively little data on IBD and especially
IBD-related mental health/QoL concerns in non-Western (e.g. Chinese) populations, thereby increasing
the importance of this study.
Abstract: The correlations between disease activity, psychological symptoms, social support, and IBD
HRQoL is not unknown, as the authors suggest at times, since several studies have addressed these
topics. Rather, the study of these topics in a Chinese population is the novel aspect and can be clarified
in the abstract.
Background: 2nd paragraph - Please provide references for sentence 2 and specify the currency for the
per-patient indirect costs reported.
Broadly the authors state a variety of factors that impact HrQoL (physical, economical, psycho-social,
and potentially demographic), but then they state that the factors that relate to HrQoL need to be
established, which seems conflicting.
Methods: Please provide (and/or move up) reference(s) for validity and reliability of the IBDQ across
cultures/countries.
Regarding disease activity indices: the stated indices may be more commonly known (in the US) as the
SCCAI (Simple Clinical Colitis Activity Index) and the Harvey-Bradshaw Index. 
Unclear if the Chinese versions of HADS and SSRS are validated for the studied population. If so,
please state and reference. If not, please acknowledge this potential limitation.
Although a score of 4 and greater is considered active disease for both the UC and Crohn's disease
activity indices, the range of the scores is potentially different, and it is therefore unclear that the scores
can be considered together in correlative analyses.
Table 2 include "(r)" in title may clarify table contents.
As  the  authors  mention, there are  a number of variables  (i.e. marital  status, income, etc) which
potentially impact social support and appeared to be collected for the study, but were not analyzed. It is
unclear why they were not analyzed.
Several small typos throughout.
Are the methods appropriate and well described?
If not, please specify what is required in your comments to the authors.
Yes
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 recommend additional statistical review
Quality of written English
Please indicate the quality of language in the manuscript:
Needs some language corrections before being published
Declaration of competing interests
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or has applied for patents relating to the content of the manuscript?
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