Title: Major complications after percutaneous biopsy of native or transplanted liver in pediatric
patients: A nationwide inpatient database study in Japan
Version: 1 Date: 20 Jun 2022
Reviewer's report:
The manuscript is well written. As I read it, I had several questions and the answers to some of
these may affect data interpretation:
1. Are patients routinely admitted for liver biopsy in Japan, or does hospital admission correlate
with severe illness that may affect risks? The risks may differ for outpatients.
2. The risks are reported to be lower in transplanted livers, but those patients were also older than
native liver patients. How much of the difference could be attributed to age? Did you compare
outcomes in each group when stratified by age alone, or were other factors age-matched for
comparison, since younger age was a risk factor?
3. Why did you choose +/- 1.28 SD weight to determine over/under weight? Typically the normal
range includes  +/- 2 SD.
4. Was cirrhosis associated with increased bleeding risk? (In kidney biopsies extensive scarring
and fibrosis increases bleeding risk, but I don't know if the same is true for liver biopsies).
Minor:
1. In the background, page 5, end of paragraph 2, should 0.91% OR 1.7% be changed to 0.91%
TO 1.7%?
Title: Major complications after percutaneous biopsy of native or transplanted liver in pediatric
patients: A nationwide inpatient database study in Japan
Version: 1 Date: 20 Jun 2022
Reviewer's report:
The manuscript is well written. As I read it, I had several questions and the answers to some of
these may affect data interpretation:
1. Are patients routinely admitted for liver biopsy in Japan, or does hospital admission correlate
with severe illness that may affect risks? The risks may differ for outpatients.
2. The risks are reported to be lower in transplanted livers, but those patients were also older than
native liver patients. How much of the difference could be attributed to age? Did you compare
outcomes in each group when stratified by age alone, or were other factors age-matched for
comparison, since younger age was a risk factor?
3. Why did you choose +/- 1.28 SD weight to determine over/under weight? Typically the normal
range includes  +/- 2 SD.
4. Was cirrhosis associated with increased bleeding risk? (In kidney biopsies extensive scarring
and fibrosis increases bleeding risk, but I don't know if the same is true for liver biopsies).
Minor:
1. In the background, page 5, end of paragraph 2, should 0.91% OR 1.7% be changed to 0.91%
TO 1.7%?
Please review this paper.
user
Title: Major complications after percutaneous biopsy of native or transplanted liver in pediatric
patients: A nationwide inpatient database study in Japan
Version: 1 Date: 20 Jun 2022
Reviewer's report:
The manuscript is well written. As I read it, I had several questions and the answers to some of
these may affect data interpretation:
1. Are patients routinely admitted for liver biopsy in Japan, or does hospital admission correlate
with severe illness that may affect risks? The risks may differ for outpatients.
2. The risks are reported to be lower in transplanted livers, but those patients were also older than
native liver patients. How much of the difference could be attributed to age? Did you compare
outcomes in each group when stratified by age alone, or were other factors age-matched for
comparison, since younger age was a risk factor?
3. Why did you choose +/- 1.28 SD weight to determine over/under weight? Typically the normal
range includes  +/- 2 SD.
4. Was cirrhosis associated with increased bleeding risk? (In kidney biopsies extensive scarring
and fibrosis increases bleeding risk, but I don't know if the same is true for liver biopsies).
Minor:
1. In the background, page 5, end of paragraph 2, should 0.91% OR 1.7% be changed to 0.91%
TO 1.7%?
assistant