Title: Epidemiology, Validation, and Clinical Characteristics of Inflammatory Bowel Disease:
The ABIS birth cohort study
Version: 1 Date: 16 Apr 2023
Reviewer's report:
This study aims at describing and validating a regional Swedish database for use primarily
in pediatric IBD research. The study is relevant and the methods sound. I only have a few
comments:
1.  The definition of IBD-U (mix of IBD codes) is in my opinion - and based on the literature -
not valid. A more correct description would simply be "undefined IBD" or "UC+CD".
2. A minor point that is unlikely to markedly change the results: Why use Kaplan-Meier
estimates and not cumulative incidences? The Kaplan-Meier approach is for survival analysis
only.
3. In the third paragraph of the discussion section, you refer to a Danish birth cohort study and
mention differences in IBD incidence rates between two age groups with a significant overlap
(< 18 years and 16-25 years). Must be a typo.
Title: Epidemiology, Validation, and Clinical Characteristics of Inflammatory Bowel Disease:
The ABIS birth cohort study
Version: 1 Date: 16 Apr 2023
Reviewer's report:
This study aims at describing and validating a regional Swedish database for use primarily
in pediatric IBD research. The study is relevant and the methods sound. I only have a few
comments:
1.  The definition of IBD-U (mix of IBD codes) is in my opinion - and based on the literature -
not valid. A more correct description would simply be "undefined IBD" or "UC+CD".
2. A minor point that is unlikely to markedly change the results: Why use Kaplan-Meier
estimates and not cumulative incidences? The Kaplan-Meier approach is for survival analysis
only.
3. In the third paragraph of the discussion section, you refer to a Danish birth cohort study and
mention differences in IBD incidence rates between two age groups with a significant overlap
(< 18 years and 16-25 years). Must be a typo.
Please review this paper.
user
Title: Epidemiology, Validation, and Clinical Characteristics of Inflammatory Bowel Disease:
The ABIS birth cohort study
Version: 1 Date: 16 Apr 2023
Reviewer's report:
This study aims at describing and validating a regional Swedish database for use primarily
in pediatric IBD research. The study is relevant and the methods sound. I only have a few
comments:
1.  The definition of IBD-U (mix of IBD codes) is in my opinion - and based on the literature -
not valid. A more correct description would simply be "undefined IBD" or "UC+CD".
2. A minor point that is unlikely to markedly change the results: Why use Kaplan-Meier
estimates and not cumulative incidences? The Kaplan-Meier approach is for survival analysis
only.
3. In the third paragraph of the discussion section, you refer to a Danish birth cohort study and
mention differences in IBD incidence rates between two age groups with a significant overlap
(< 18 years and 16-25 years). Must be a typo.
assistant