Title: Optimal Endoscopy Timing in Elderly Patients Presenting with Acute Non-Variceal
Upper Gastrointestinal Bleeding.
Version: 7 Date: 12 Aug 2024
Reviewer:  Riccardo Marmo
Reviewer's report:
The primary endpoint of the study was 30-day mortality; but this event occurred in 50 patients
(10,7%). Please use the death rate as the baseline reference for your sample size calculation.
The statement “Taking the effect size as 0.4, #=0.05, and power (1-#) =0.80, the study population
was determined as 66 patients at a 95% confidence level” seems unrealistic; the effect of the age
(> or < 65 years) should impact the mortality rate to such an extent that in the higher mortality
group the estimate mortality could be of 50.7% (.40 + .107).
In the table 2 the mortality in the two groups was 4.8% vs 15.4%; I suggest to use the mortality
rate described in literature as a reference (reporting the literature) and to consider the impact
that the age >= 65 can lead on the mortality risk. For example, if the reference mortality is 10%
and age >= 65 impacts for an increase of the relative risk of 50% , the absolute difference is
(.10 ±.05) - .10 i.e .05.
I suggest to re-evaluate your sample size “ considering the mortality rate of xxx and taking the
effect size as xxx  of absolute difference, #=0.05, and power (1-#) =0.80, the study population
was determined as xxx patients at a 95% confidence level”.
On table 1 the two group are significantly different for many variables
Gender, Comorbidities,PPI usage,  Previous history of GIS surgery, Medication,
Antiaggregants,    Anticoagulants, Hgb level on admission, Urea level on admission
INR on admission ,Serum albumin level on admission
Use the primary end point as a dependent variable, include the variables significantly different
between the two groups in a multivariate logistic regression and evaluate their independent role
predicting the primary  outcome. Include also the two age groups as independent factor.
Title: Optimal Endoscopy Timing in Elderly Patients Presenting with Acute Non-Variceal
Upper Gastrointestinal Bleeding.
Version: 7 Date: 12 Aug 2024
Reviewer:  Riccardo Marmo
Reviewer's report:
The primary endpoint of the study was 30-day mortality; but this event occurred in 50 patients
(10,7%). Please use the death rate as the baseline reference for your sample size calculation.
The statement “Taking the effect size as 0.4, #=0.05, and power (1-#) =0.80, the study population
was determined as 66 patients at a 95% confidence level” seems unrealistic; the effect of the age
(> or < 65 years) should impact the mortality rate to such an extent that in the higher mortality
group the estimate mortality could be of 50.7% (.40 + .107).
In the table 2 the mortality in the two groups was 4.8% vs 15.4%; I suggest to use the mortality
rate described in literature as a reference (reporting the literature) and to consider the impact
that the age >= 65 can lead on the mortality risk. For example, if the reference mortality is 10%
and age >= 65 impacts for an increase of the relative risk of 50% , the absolute difference is
(.10 ±.05) - .10 i.e .05.
I suggest to re-evaluate your sample size “ considering the mortality rate of xxx and taking the
effect size as xxx  of absolute difference, #=0.05, and power (1-#) =0.80, the study population
was determined as xxx patients at a 95% confidence level”.
On table 1 the two group are significantly different for many variables
Gender, Comorbidities,PPI usage,  Previous history of GIS surgery, Medication,
Antiaggregants,    Anticoagulants, Hgb level on admission, Urea level on admission
INR on admission ,Serum albumin level on admission
Use the primary end point as a dependent variable, include the variables significantly different
between the two groups in a multivariate logistic regression and evaluate their independent role
predicting the primary  outcome. Include also the two age groups as independent factor.
Please review this paper.
user
Title: Optimal Endoscopy Timing in Elderly Patients Presenting with Acute Non-Variceal
Upper Gastrointestinal Bleeding.
Version: 7 Date: 12 Aug 2024
Reviewer:  Riccardo Marmo
Reviewer's report:
The primary endpoint of the study was 30-day mortality; but this event occurred in 50 patients
(10,7%). Please use the death rate as the baseline reference for your sample size calculation.
The statement “Taking the effect size as 0.4, #=0.05, and power (1-#) =0.80, the study population
was determined as 66 patients at a 95% confidence level” seems unrealistic; the effect of the age
(> or < 65 years) should impact the mortality rate to such an extent that in the higher mortality
group the estimate mortality could be of 50.7% (.40 + .107).
In the table 2 the mortality in the two groups was 4.8% vs 15.4%; I suggest to use the mortality
rate described in literature as a reference (reporting the literature) and to consider the impact
that the age >= 65 can lead on the mortality risk. For example, if the reference mortality is 10%
and age >= 65 impacts for an increase of the relative risk of 50% , the absolute difference is
(.10 ±.05) - .10 i.e .05.
I suggest to re-evaluate your sample size “ considering the mortality rate of xxx and taking the
effect size as xxx  of absolute difference, #=0.05, and power (1-#) =0.80, the study population
was determined as xxx patients at a 95% confidence level”.
On table 1 the two group are significantly different for many variables
Gender, Comorbidities,PPI usage,  Previous history of GIS surgery, Medication,
Antiaggregants,    Anticoagulants, Hgb level on admission, Urea level on admission
INR on admission ,Serum albumin level on admission
Use the primary end point as a dependent variable, include the variables significantly different
between the two groups in a multivariate logistic regression and evaluate their independent role
predicting the primary  outcome. Include also the two age groups as independent factor.
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