Review for 10.1186/s12876-022-02516-2 (2022)

Title: The 30-day hospital readmission and mortality after surgery in colorectal cancer patients
Version: 3 Date: 10 Jun 2022
Reviewer's report:
This Saudi population-based study tried to analyze 30-day unplanned readmission rates , the
etiology of readmission and mortality in colorectal cancer surgery patients. Though this would
be an important study however the data reflected in this study fails to shed enough light on the
topic. I would recommend rejecting the paper for the following reasons:
1) Results section- paragraph 1-  "The average age was 60.79 years with almost 60% of the
sample being males and more than 78% were married. The average BMI was 27.28 kg/m2and
nearly 70% of the patients did not have any comorbid conditions.”- discussion is about the total
population rather than focus on differences between readmission and nonreadmission
2) Result section- states a positive association between age and readmission, however, there is
no sample size provided in table 1 about the various age categories, that being said the mean age
of the total population is 60.79, unclear about the true association of comparing the various age
categories with those <40, also is statistically insignificant.
3) Result section-Similarly females were said to have a higher association but not statistically
significant
4) Result section- paragraph 3- The sample size of patients readmitted with localized tumor
is 4, it would be inappropriate to use it in Logistic regression model and to state that patients
diagnosed with distant metastatic disease have 4.09 higher odds of readmission (odds ratio
4.09, 95% confidence intervals 1.29-12.98).- the wide confidence interval strengthens the
overestimation of odds ratio by using analysis method.
5) Result section- paragraph 3—Similarly, this again invalidates the statement - "Likewise,
patients discharged to locations other than post-anesthesia care or ICU have 3.75 higher odds of
readmission (odds ratio 3.75, 95% confidence intervals 1.19-11.80)” -  sample size of patients
readmission who were discharged to other was small and again overestimates the odds ratio,
also reinforced by the wide Confidence interval
6) Result section- paragraph 4- "When adjusting for marital status, stage at diagnosis and
discharge location, females were 89% more likely to be readmitted compared to males (odds
ratio 1.89, 95% confidence intervals 1.00-3.58). “- Unclear about the implication of adjusting
for marital status, also is statistically insignificant,
7) Results section- paragraph 4- Line 2 has repetitive information from paragraph 3
8) Result section- paragraph 4- There is no statistically significant difference in the survivability
amongst those readmitted and those not readmitted
9) Table 3- identifies Gastrointestinal as one of the major reasons for readmission but what does
that entail?
10) Discussion section- paragraph 3- "we observed that 24.30% of our metastatic patients were
readmitted”- unclear as to where is this information reflected
11) Discussion section- states that no association between readmission and comorbidities, LOS,
or surgical approach- the sample size was small for comorbidities again invalidates the analysis
used to derive this statement.
12) Discussion section- Authors acknowledged that Socioeconomic status is a known factor that
has affected readmissions, however, this paper claim that its effect would be modest without
providing any data.
11 ) The paper discusses early identification of the CRC rather than the impact of identification
of readmission factors and causes refuting the purpose of this paper.
12) This paper lacks to provide sufficient data to identify the risk factors for readmission, reasons
for readmission or mortality difference between those readmitted and those not.