Title: Serum creatinine/cystatin C ratio as a surrogate marker for sarcopenia in patients with
gastric cancer
Version: 1 Date: 12 Sep 2021
Reviewer's report:
The authors reported “serum creatinine/cystain C ratio as a surrogate marker for sarcopenica
in patients with gastric cancer”. The authors concluded that serum Cr/CysC ratio can be used
accurately, inexpensively, and easily to evaluate sarcopenia in patients with gastric cancer. Our
study showed that sarcopenia is possible in patients with Cr/CysC <0.67, indicating a poor
prognosis.
There are many critical problems in this paper, I think. Especially from statistical view.
1. The sample size of this cohort is very small. I do not think the results of this study has
robustness.
2. Generally, the range of AUC is from 0.5 (toss the coin) to 1.0 (perfect prediction). I cannot
understand the AUC of CysC is 0.441.
3. I know AUC of ROC is not absolute value. However, I convince the AUC value of 0.665
has no clinical value.
4. The value of correlation coefficient: 0.269 does not have strong correlation,
0.7-1.0: strong correlation, 0.4-0.7; correlation 0.2-0.4; weak correlation
5. The numbers of event of low skeletal muscle mass index is 36 cases. From the statistical
viewpoint, the maximum numbers of covariates that researchers can calculate in multivariate
model is 3 or 4, at most. However, the authors calculate 6 covariates in logistic regression
analysis. This method leads wrong conclusions.
6. The authors perform survival analysis only by univariate model. Multivariable analysis should
be necessary.
7. What is the clinical value of this study? The authors should describe this point at last of
discussion part.
8. The authors did not show the serum creatinine/cystain C ratio when compared other previously
reported factors.
Title: Serum creatinine/cystatin C ratio as a surrogate marker for sarcopenia in patients with
gastric cancer
Version: 1 Date: 12 Sep 2021
Reviewer's report:
The authors reported “serum creatinine/cystain C ratio as a surrogate marker for sarcopenica
in patients with gastric cancer”. The authors concluded that serum Cr/CysC ratio can be used
accurately, inexpensively, and easily to evaluate sarcopenia in patients with gastric cancer. Our
study showed that sarcopenia is possible in patients with Cr/CysC <0.67, indicating a poor
prognosis.
There are many critical problems in this paper, I think. Especially from statistical view.
1. The sample size of this cohort is very small. I do not think the results of this study has
robustness.
2. Generally, the range of AUC is from 0.5 (toss the coin) to 1.0 (perfect prediction). I cannot
understand the AUC of CysC is 0.441.
3. I know AUC of ROC is not absolute value. However, I convince the AUC value of 0.665
has no clinical value.
4. The value of correlation coefficient: 0.269 does not have strong correlation,
0.7-1.0: strong correlation, 0.4-0.7; correlation 0.2-0.4; weak correlation
5. The numbers of event of low skeletal muscle mass index is 36 cases. From the statistical
viewpoint, the maximum numbers of covariates that researchers can calculate in multivariate
model is 3 or 4, at most. However, the authors calculate 6 covariates in logistic regression
analysis. This method leads wrong conclusions.
6. The authors perform survival analysis only by univariate model. Multivariable analysis should
be necessary.
7. What is the clinical value of this study? The authors should describe this point at last of
discussion part.
8. The authors did not show the serum creatinine/cystain C ratio when compared other previously
reported factors.
Please review this paper.
user
Title: Serum creatinine/cystatin C ratio as a surrogate marker for sarcopenia in patients with
gastric cancer
Version: 1 Date: 12 Sep 2021
Reviewer's report:
The authors reported “serum creatinine/cystain C ratio as a surrogate marker for sarcopenica
in patients with gastric cancer”. The authors concluded that serum Cr/CysC ratio can be used
accurately, inexpensively, and easily to evaluate sarcopenia in patients with gastric cancer. Our
study showed that sarcopenia is possible in patients with Cr/CysC <0.67, indicating a poor
prognosis.
There are many critical problems in this paper, I think. Especially from statistical view.
1. The sample size of this cohort is very small. I do not think the results of this study has
robustness.
2. Generally, the range of AUC is from 0.5 (toss the coin) to 1.0 (perfect prediction). I cannot
understand the AUC of CysC is 0.441.
3. I know AUC of ROC is not absolute value. However, I convince the AUC value of 0.665
has no clinical value.
4. The value of correlation coefficient: 0.269 does not have strong correlation,
0.7-1.0: strong correlation, 0.4-0.7; correlation 0.2-0.4; weak correlation
5. The numbers of event of low skeletal muscle mass index is 36 cases. From the statistical
viewpoint, the maximum numbers of covariates that researchers can calculate in multivariate
model is 3 or 4, at most. However, the authors calculate 6 covariates in logistic regression
analysis. This method leads wrong conclusions.
6. The authors perform survival analysis only by univariate model. Multivariable analysis should
be necessary.
7. What is the clinical value of this study? The authors should describe this point at last of
discussion part.
8. The authors did not show the serum creatinine/cystain C ratio when compared other previously
reported factors.
assistant