Title: Clustering of pediatric onset inflammatory bowel disease in Finland: A nationwide
register-based study
Version: 2 Date: 25 Sep 2022
Reviewer:  Mikkel Malham
Reviewer's report:
First of all, thank you to the editors and authors for letting me review this well written paper
elaborating on the increasing incidence of pIBD – more specifically looking at the time and
space clustering. I only have minor comments and no major concerns. However, because I have
not previously worked with the specific statistical tests used, I think this paper should also be
reviewed by someone who has.
In general there are only few language problems, however, the authors should be consisten on
how they punctuate (UK or US and 1000 or 1,000).
Abstract:
- L29P2: “Pediatric inflammatory bowel disease” should be “Pediatric onset inflammatory bowel
disease” as written in the abbreviations section.
- L31P2: Sentence starting with “we evaluated (…)” consider adding “and place of residence
at time of PIBD onset (or diagnosis?)”
- L36P2: I find the sentence starting with “the date of the diagnosis (…)” difficult to understand.
- L37P2: What is a diagnosis address? The subjects address at the time of diagnosis?
Background:
- L70P3: What about the other Nordic countries? The same increasing tendency offers support
for your hypothesis. Consider adding more recent references – maybe “The incidence and
prevalence of paediatric- and adult-onset inflammatory bowel disease in Denmark during a 37-
year period - a nationwide cohort study (1980-2017)” (DOI: 10.1093/ecco-jcc/jjac138).
- L72-3P3: “(…)north than in the south has been reported”. North or south of what? Finland?
Methods:
The good coverage of the Finish SII is well known and well described in the paper. I lack more
knowledge on how the addresses were found and how the coordinates were derived and lastly
how these were translated into distances and compared between cases and controls. In short, I
find it a little difficult to understand the study methodology.
- L91P4The authors state that IBD subtypes are known from 2000 and forth. How was the cases
from 1992-2000 phenotyped?
- L95P4: I would suggest rephrasing the sentence ending with “(…) controls selected for the
case” to “date for the matched controls.”.
- L101P4: I think sex was forgotten in the matching criteria.
- P114P5: I am a little unsure of what the months 2,4,6,12 are a measure of. Time intervals?
Discussion
Generally, I would appreciate a more detailed description of what the study actually found and
why this is important.
- Why does the authors think that only UC should a clustering tendency?
- Can the authors look further into the UC cases where clustering was found – urban or rural
areas?
- Does the authors think the section starting at line 193 is important?
Title: Clustering of pediatric onset inflammatory bowel disease in Finland: A nationwide
register-based study
Version: 2 Date: 25 Sep 2022
Reviewer:  Mikkel Malham
Reviewer's report:
First of all, thank you to the editors and authors for letting me review this well written paper
elaborating on the increasing incidence of pIBD – more specifically looking at the time and
space clustering. I only have minor comments and no major concerns. However, because I have
not previously worked with the specific statistical tests used, I think this paper should also be
reviewed by someone who has.
In general there are only few language problems, however, the authors should be consisten on
how they punctuate (UK or US and 1000 or 1,000).
Abstract:
- L29P2: “Pediatric inflammatory bowel disease” should be “Pediatric onset inflammatory bowel
disease” as written in the abbreviations section.
- L31P2: Sentence starting with “we evaluated (…)” consider adding “and place of residence
at time of PIBD onset (or diagnosis?)”
- L36P2: I find the sentence starting with “the date of the diagnosis (…)” difficult to understand.
- L37P2: What is a diagnosis address? The subjects address at the time of diagnosis?
Background:
- L70P3: What about the other Nordic countries? The same increasing tendency offers support
for your hypothesis. Consider adding more recent references – maybe “The incidence and
prevalence of paediatric- and adult-onset inflammatory bowel disease in Denmark during a 37-
year period - a nationwide cohort study (1980-2017)” (DOI: 10.1093/ecco-jcc/jjac138).
- L72-3P3: “(…)north than in the south has been reported”. North or south of what? Finland?
Methods:
The good coverage of the Finish SII is well known and well described in the paper. I lack more
knowledge on how the addresses were found and how the coordinates were derived and lastly
how these were translated into distances and compared between cases and controls. In short, I
find it a little difficult to understand the study methodology.
- L91P4The authors state that IBD subtypes are known from 2000 and forth. How was the cases
from 1992-2000 phenotyped?
- L95P4: I would suggest rephrasing the sentence ending with “(…) controls selected for the
case” to “date for the matched controls.”.
- L101P4: I think sex was forgotten in the matching criteria.
- P114P5: I am a little unsure of what the months 2,4,6,12 are a measure of. Time intervals?
Discussion
Generally, I would appreciate a more detailed description of what the study actually found and
why this is important.
- Why does the authors think that only UC should a clustering tendency?
- Can the authors look further into the UC cases where clustering was found – urban or rural
areas?
- Does the authors think the section starting at line 193 is important?
Please review this paper.
user
Title: Clustering of pediatric onset inflammatory bowel disease in Finland: A nationwide
register-based study
Version: 2 Date: 25 Sep 2022
Reviewer:  Mikkel Malham
Reviewer's report:
First of all, thank you to the editors and authors for letting me review this well written paper
elaborating on the increasing incidence of pIBD – more specifically looking at the time and
space clustering. I only have minor comments and no major concerns. However, because I have
not previously worked with the specific statistical tests used, I think this paper should also be
reviewed by someone who has.
In general there are only few language problems, however, the authors should be consisten on
how they punctuate (UK or US and 1000 or 1,000).
Abstract:
- L29P2: “Pediatric inflammatory bowel disease” should be “Pediatric onset inflammatory bowel
disease” as written in the abbreviations section.
- L31P2: Sentence starting with “we evaluated (…)” consider adding “and place of residence
at time of PIBD onset (or diagnosis?)”
- L36P2: I find the sentence starting with “the date of the diagnosis (…)” difficult to understand.
- L37P2: What is a diagnosis address? The subjects address at the time of diagnosis?
Background:
- L70P3: What about the other Nordic countries? The same increasing tendency offers support
for your hypothesis. Consider adding more recent references – maybe “The incidence and
prevalence of paediatric- and adult-onset inflammatory bowel disease in Denmark during a 37-
year period - a nationwide cohort study (1980-2017)” (DOI: 10.1093/ecco-jcc/jjac138).
- L72-3P3: “(…)north than in the south has been reported”. North or south of what? Finland?
Methods:
The good coverage of the Finish SII is well known and well described in the paper. I lack more
knowledge on how the addresses were found and how the coordinates were derived and lastly
how these were translated into distances and compared between cases and controls. In short, I
find it a little difficult to understand the study methodology.
- L91P4The authors state that IBD subtypes are known from 2000 and forth. How was the cases
from 1992-2000 phenotyped?
- L95P4: I would suggest rephrasing the sentence ending with “(…) controls selected for the
case” to “date for the matched controls.”.
- L101P4: I think sex was forgotten in the matching criteria.
- P114P5: I am a little unsure of what the months 2,4,6,12 are a measure of. Time intervals?
Discussion
Generally, I would appreciate a more detailed description of what the study actually found and
why this is important.
- Why does the authors think that only UC should a clustering tendency?
- Can the authors look further into the UC cases where clustering was found – urban or rural
areas?
- Does the authors think the section starting at line 193 is important?
assistant