Title: Development of a scoring model based on objective factors to predict gangrenous/
perforated appendicitis
Version: 1 Date: 01 Feb 2023
Reviewer:  Jun Fujishiro
Reviewer's report:
In this study, the authors developed a prediction model for gangrenous/perforated appendicitis
(GPA). They retrospectively analyzed 151 patients who were diagnosed with acute appendicitis
based on clinical symptoms and CT findings and underwent emergency surgery at their
institution. Objective patient characteristics, clinical preoperative variables, and CT findings
were used for the model development. Only the following objective CT findings were included:
the maximal outer diameter of the appendix (in mm), the presence of appendiceal fecalith, and
the presence of free intraperitoneal #uid.
Their scoring model for predicting GPA included CRP, the maximal outer diameter of the
appendix by CT, and the presence of appendiceal fecalith by CT. ROC analysis for the scoring
model indicated moderate discrimination with an AUC of 0.792 (95% CI, 0.721–0.863).
They concluded that their scoring model using only objective variables can be easily used in
clinical practice in most hospitals and even in difficult settings.
While the methodology of the model development is acceptable, there are the following major
concerns in this manuscript.
1: CT findings used in the study.
The authors used only objective CT findings, namely the maximal outer diameter of the
appendix, the presence of appendiceal fecalith, and the presence of free intraperitoneal #uid,
in the model development. The study did not include other CT findings that are useful for
the discrimination of GPA such as contrast enhancement defect of the appendiceal wall,
extraluminal/intraluminal air, and peri-appendiceal fat stranding. While these CT findings
are not thoroughly objective, most surgeons, radiologists, and other doctors who treat acute
appendicitis can judge these CT findings. Excluding these "not objective" CT findings was not
realistic in clinical settings when a CT scan was examined for patients suspicious of GPA, and
excluding these findings from the model development is not reasonable. The model would be
more predictive with the use of these CT findings.
2: The comparison of the developed model with previously reported ones
The performance of the model developed in the study was not compared with that of the
previously reported models for the discrimination of GPA or complicated appendicitis. The
value of the model or the study will be evaluated with the comparison.
There are the following minor issues in this manuscript.
The main feature of the study, only objective CT findings were used in this model, is not
described in the title and abstract.
Basic clinical practice for acute appendicitis at their institution such as an indication of CT
scan and selection criteria for the treatment (emergency surgery or non-operative management).
These may influence the model in this study. There are apparently more GPA patients (56.3%)
than that is expected in the real world.
Title: Development of a scoring model based on objective factors to predict gangrenous/
perforated appendicitis
Version: 1 Date: 01 Feb 2023
Reviewer:  Jun Fujishiro
Reviewer's report:
In this study, the authors developed a prediction model for gangrenous/perforated appendicitis
(GPA). They retrospectively analyzed 151 patients who were diagnosed with acute appendicitis
based on clinical symptoms and CT findings and underwent emergency surgery at their
institution. Objective patient characteristics, clinical preoperative variables, and CT findings
were used for the model development. Only the following objective CT findings were included:
the maximal outer diameter of the appendix (in mm), the presence of appendiceal fecalith, and
the presence of free intraperitoneal #uid.
Their scoring model for predicting GPA included CRP, the maximal outer diameter of the
appendix by CT, and the presence of appendiceal fecalith by CT. ROC analysis for the scoring
model indicated moderate discrimination with an AUC of 0.792 (95% CI, 0.721–0.863).
They concluded that their scoring model using only objective variables can be easily used in
clinical practice in most hospitals and even in difficult settings.
While the methodology of the model development is acceptable, there are the following major
concerns in this manuscript.
1: CT findings used in the study.
The authors used only objective CT findings, namely the maximal outer diameter of the
appendix, the presence of appendiceal fecalith, and the presence of free intraperitoneal #uid,
in the model development. The study did not include other CT findings that are useful for
the discrimination of GPA such as contrast enhancement defect of the appendiceal wall,
extraluminal/intraluminal air, and peri-appendiceal fat stranding. While these CT findings
are not thoroughly objective, most surgeons, radiologists, and other doctors who treat acute
appendicitis can judge these CT findings. Excluding these "not objective" CT findings was not
realistic in clinical settings when a CT scan was examined for patients suspicious of GPA, and
excluding these findings from the model development is not reasonable. The model would be
more predictive with the use of these CT findings.
2: The comparison of the developed model with previously reported ones
The performance of the model developed in the study was not compared with that of the
previously reported models for the discrimination of GPA or complicated appendicitis. The
value of the model or the study will be evaluated with the comparison.
There are the following minor issues in this manuscript.
The main feature of the study, only objective CT findings were used in this model, is not
described in the title and abstract.
Basic clinical practice for acute appendicitis at their institution such as an indication of CT
scan and selection criteria for the treatment (emergency surgery or non-operative management).
These may influence the model in this study. There are apparently more GPA patients (56.3%)
than that is expected in the real world.
Please review this paper.
user
Title: Development of a scoring model based on objective factors to predict gangrenous/
perforated appendicitis
Version: 1 Date: 01 Feb 2023
Reviewer:  Jun Fujishiro
Reviewer's report:
In this study, the authors developed a prediction model for gangrenous/perforated appendicitis
(GPA). They retrospectively analyzed 151 patients who were diagnosed with acute appendicitis
based on clinical symptoms and CT findings and underwent emergency surgery at their
institution. Objective patient characteristics, clinical preoperative variables, and CT findings
were used for the model development. Only the following objective CT findings were included:
the maximal outer diameter of the appendix (in mm), the presence of appendiceal fecalith, and
the presence of free intraperitoneal #uid.
Their scoring model for predicting GPA included CRP, the maximal outer diameter of the
appendix by CT, and the presence of appendiceal fecalith by CT. ROC analysis for the scoring
model indicated moderate discrimination with an AUC of 0.792 (95% CI, 0.721–0.863).
They concluded that their scoring model using only objective variables can be easily used in
clinical practice in most hospitals and even in difficult settings.
While the methodology of the model development is acceptable, there are the following major
concerns in this manuscript.
1: CT findings used in the study.
The authors used only objective CT findings, namely the maximal outer diameter of the
appendix, the presence of appendiceal fecalith, and the presence of free intraperitoneal #uid,
in the model development. The study did not include other CT findings that are useful for
the discrimination of GPA such as contrast enhancement defect of the appendiceal wall,
extraluminal/intraluminal air, and peri-appendiceal fat stranding. While these CT findings
are not thoroughly objective, most surgeons, radiologists, and other doctors who treat acute
appendicitis can judge these CT findings. Excluding these "not objective" CT findings was not
realistic in clinical settings when a CT scan was examined for patients suspicious of GPA, and
excluding these findings from the model development is not reasonable. The model would be
more predictive with the use of these CT findings.
2: The comparison of the developed model with previously reported ones
The performance of the model developed in the study was not compared with that of the
previously reported models for the discrimination of GPA or complicated appendicitis. The
value of the model or the study will be evaluated with the comparison.
There are the following minor issues in this manuscript.
The main feature of the study, only objective CT findings were used in this model, is not
described in the title and abstract.
Basic clinical practice for acute appendicitis at their institution such as an indication of CT
scan and selection criteria for the treatment (emergency surgery or non-operative management).
These may influence the model in this study. There are apparently more GPA patients (56.3%)
than that is expected in the real world.
assistant