Title: The cost of illness analysis of inflammatory bowel disease
Version: 1 Date: 02 Nov 2022
Reviewer's report:
Thank you for this study assessing costs associated with inflammatory bowel disease in Iran.
Please clarify how this can be a cross-sectional analysis if you are assessing cost over time.
What was diagnostic criteria for confirming a diagnosis of IBD? Did this include only Crohn’s
disease and ulcerative colitis? What about other entities such as microscopic colitis? Was scope
or pathology required for confirmation of diagnosis?
Please define disease progression.
Please provide further detail regarding the calculation of sample volume. How did you calculate
estimates of cost? Where does margin error of 6% come from?
Why is physiotherapy relevant to cost associated with IBD in this situation?
Please justify scaling up by a factor of 4 to extrapolate cost over a 1-year period – ie, does this
mean a patient who underwent colonoscopy or surgery is then calculated to have 4 colonoscopies
or surgeries over the course of 1 year? This does not seem reasonable.
Was there a study protocol that defined the number of phone calls or point of contact required
for the data collection?
Are hours of paid household help considered and IBD-specific cost? What about household help
for people without illness or with alternate illnesses?
Did you obtain wage information for each patient based on occupation? Is absenteeism of
caregiver a cost borne by the patient or does that reflect an alternate caregiver reason for
absenteeism?
Is work productivity loss/absenteeism only related to hospitalization? Why is each
hospitalization assumed to be 14 days? How do you assess cost of hospitalization itself?
How did you define early retirement and assess if early retirement was a consequence of IBD?
Please comment on why aminosalicylates share the highest cost of medication type in
comparison to biologics.
Please include costs of each drug, procedure, surgery etc in a supplementary table.
The analysis conflates cost attributed to patients and estimated costs due to premature death
or cost of illness for country on a population level. It is difficult to understand some of the
conclusions when the cost information is rather opaque. There are significant methodological
questions regarding issues such as data acquisition and cost calculation. This is an important
question to understand with potential impacts at a population level. In the current form, this
study requires substantial revision and re-calculation for a more robust cost analysis.
Title: The cost of illness analysis of inflammatory bowel disease
Version: 1 Date: 02 Nov 2022
Reviewer's report:
Thank you for this study assessing costs associated with inflammatory bowel disease in Iran.
Please clarify how this can be a cross-sectional analysis if you are assessing cost over time.
What was diagnostic criteria for confirming a diagnosis of IBD? Did this include only Crohn’s
disease and ulcerative colitis? What about other entities such as microscopic colitis? Was scope
or pathology required for confirmation of diagnosis?
Please define disease progression.
Please provide further detail regarding the calculation of sample volume. How did you calculate
estimates of cost? Where does margin error of 6% come from?
Why is physiotherapy relevant to cost associated with IBD in this situation?
Please justify scaling up by a factor of 4 to extrapolate cost over a 1-year period – ie, does this
mean a patient who underwent colonoscopy or surgery is then calculated to have 4 colonoscopies
or surgeries over the course of 1 year? This does not seem reasonable.
Was there a study protocol that defined the number of phone calls or point of contact required
for the data collection?
Are hours of paid household help considered and IBD-specific cost? What about household help
for people without illness or with alternate illnesses?
Did you obtain wage information for each patient based on occupation? Is absenteeism of
caregiver a cost borne by the patient or does that reflect an alternate caregiver reason for
absenteeism?
Is work productivity loss/absenteeism only related to hospitalization? Why is each
hospitalization assumed to be 14 days? How do you assess cost of hospitalization itself?
How did you define early retirement and assess if early retirement was a consequence of IBD?
Please comment on why aminosalicylates share the highest cost of medication type in
comparison to biologics.
Please include costs of each drug, procedure, surgery etc in a supplementary table.
The analysis conflates cost attributed to patients and estimated costs due to premature death
or cost of illness for country on a population level. It is difficult to understand some of the
conclusions when the cost information is rather opaque. There are significant methodological
questions regarding issues such as data acquisition and cost calculation. This is an important
question to understand with potential impacts at a population level. In the current form, this
study requires substantial revision and re-calculation for a more robust cost analysis.
Please review this paper.
user
Title: The cost of illness analysis of inflammatory bowel disease
Version: 1 Date: 02 Nov 2022
Reviewer's report:
Thank you for this study assessing costs associated with inflammatory bowel disease in Iran.
Please clarify how this can be a cross-sectional analysis if you are assessing cost over time.
What was diagnostic criteria for confirming a diagnosis of IBD? Did this include only Crohn’s
disease and ulcerative colitis? What about other entities such as microscopic colitis? Was scope
or pathology required for confirmation of diagnosis?
Please define disease progression.
Please provide further detail regarding the calculation of sample volume. How did you calculate
estimates of cost? Where does margin error of 6% come from?
Why is physiotherapy relevant to cost associated with IBD in this situation?
Please justify scaling up by a factor of 4 to extrapolate cost over a 1-year period – ie, does this
mean a patient who underwent colonoscopy or surgery is then calculated to have 4 colonoscopies
or surgeries over the course of 1 year? This does not seem reasonable.
Was there a study protocol that defined the number of phone calls or point of contact required
for the data collection?
Are hours of paid household help considered and IBD-specific cost? What about household help
for people without illness or with alternate illnesses?
Did you obtain wage information for each patient based on occupation? Is absenteeism of
caregiver a cost borne by the patient or does that reflect an alternate caregiver reason for
absenteeism?
Is work productivity loss/absenteeism only related to hospitalization? Why is each
hospitalization assumed to be 14 days? How do you assess cost of hospitalization itself?
How did you define early retirement and assess if early retirement was a consequence of IBD?
Please comment on why aminosalicylates share the highest cost of medication type in
comparison to biologics.
Please include costs of each drug, procedure, surgery etc in a supplementary table.
The analysis conflates cost attributed to patients and estimated costs due to premature death
or cost of illness for country on a population level. It is difficult to understand some of the
conclusions when the cost information is rather opaque. There are significant methodological
questions regarding issues such as data acquisition and cost calculation. This is an important
question to understand with potential impacts at a population level. In the current form, this
study requires substantial revision and re-calculation for a more robust cost analysis.
assistant