Review for 10.1186/s12876-024-03379-5 (2024)

Title: Nomogram for assistant diagnosing acute suppurative cholangitis: a case-control study
Version: 0 Date: 06 Jan 2024
Reviewer's report:
The manuscript presents a logistic regression model and a nomogram for diagnosing acute
suppurative cholangitis in patients with acute cholangitis. However, the study's rationale
contains several ambiguities that require further clarification and detailed explanation.
1. Abstract: The conclusion should succinctly highlight the most clinically impactful findings
of the study. It is essential for the readers to grasp the key message from the conclusion
without needing to refer to the entire abstract. I recommend the authors reassess their study to
provide a more substantial conclusion than "The nomogram demonstrated excellent predictive
performance in assisting in diagnosing ASC."
2. Introduction: The assertion that "ASC should be categorized as moderate-to-severe
cholangitis" requires substantiation. Please provide references or evidence supporting this
statement. The relationship between acute cholecystitis and concurrent cholangitis is not
inherently apparent. The follow-up statement about mild cholangitis diagnoses in ASC patients
according to TG18[9-11] is somewhat ambiguous, especially considering the severity grading of
acute cholecystitis/cholangitis is traditionally based on organ failure and inflammation severity,
not necessarily the presence of suppuration. This point warrants clearer explanation.
3. The introduction should also clarify the importance of differentiating ASC from non-
suppurative forms. The current references (1-6), dating from the 1990s to early 2000s, may
be outdated. Given the standardization of interventions for acute cholangitis, recent literature
highlighting prognostic differences or treatment indications between suppurative and non-
suppurative cholangitis would be more appropriate. Ideally, references from the past five years
should be included.
4. Methodology: The process of narrowing down from 650 cases to 401 patients needs more
detailed explanation.
a. A STROBE flow diagram should be provided.
b. The initial inclusion criteria and methods of screening the initial 650 cases should be detailed.
How were these 650 cases initially screened? By ICD-10 diagnosis of electronic medical record?
Are all diagnosis based on TG18?
c. The exclusion criteria and the number of cases excluded per criterion need clarification.
d. The inclusion of 401 patients who underwent biliary drainage should be elaborated. How
many were drained by ERCP? And how many were PTCD?
5. It's crucial to detail the diagnostic criteria for "suppurative" cholangitis, particularly since it
is used as a "Gold standard" in Table 3.
a. The method of diagnosis, such as bile culture, and its application to all cases, should be
clarified.
b. Information on the pathogens identified in "suppurative" bile samples is necessary.
c. The impact of empirical antibiotic treatment on the "suppurative" condition should be
explored. Did the choice and treatment course of empirical antibiotic treatment influence the
"suppurative" condition or not?
6. For the logistic regression models, more information is needed regarding the model selection
process. Specifically, what criteria were used to select factors from univariable to multivariable
analysis should be provided in the Materials and Methods section.
7. Since bile duct diameter, an important factor in the nomogram, is the sole imagine information
used in this study, further details are required.
a. Are all these measures are CBD diameter? If so, it should be specified in the text and tables
b. Are all diameters measured by CT? Did all cases received CT study for diagnosis?
c. The availability and relevance of other imaging features, such as peri-bile duct stranding or
other signs of inflammation, should be addressed.
8. The normogram includes total bile acid, a parameter not routinely measured in clinical
practice. The authors should ensure complete data availability for this parameter across all 401
cases included in the study to avoid issues of data missingness.
9. Regarding the statistical analysis in R Studio, the specific packages used should be mentioned
for clarity and reproducibility.
10. For the results of the nomogram, it is crucial to specify the cut-off value used to achieve the
stated sensitivity and specificity. Without this, the claim regarding this may need modification.
These suggestions aim to enhance the clarity and depth of your manuscript, ensuring that each
section accurately reflects your study's methodology and findings.