Review for 10.1186/1471-230X-13-95 (2013)

Reviewer's report
Title:A Multi-Country Study of Intussusception in Children Under 2 Years of Age
in Latin America: Analysis of Prospective Surveillance Data.
Version: 1Date:1 March 2013
Reviewer: Kong Boo Phua
Reviewer's report:
When assessing the work, please consider the following points:
1. Is the question posed by the authors well defined?
Yes. The study aimed to describe the epidemiology and to estimate the
incidence of IS in Latin American infants prior to new vaccine introduction.
2. Are the methods appropriate and well described?
The methodology is adequately described. However there is one query as
to whether rotavirus vaccine trial had been started during the period from
January 2003 to May 2005. The authors mentioned that ‘the surveillance
ran in parallel to the safety and efficacy trial’. How is one going to resolve
the difference between the aim of estimating the incidence of IS in Latin
American infants prior to new vaccine introduction and estimation of IS
with the ongoing rotavirus vaccine trial?
3. Are the data sound?
The data looks fine.
However, we have two figures. In the ‘Study Population- During the study
period, 476 definite IS cases in children under 2 years of age were
identified’. However, when limiting to definite IS cases living in the study
area the number was down to 385. Any reason to explain why there is
quite a large number of 91 IS children coming to the participating
hospitals from outside the catchment areas?
To be fair, in the text, there is a clear statement that the calculation of
incidence of definite IS is limited to those living in the study area.
4. Does the manuscript adhere to the relevant standards for reporting and
data deposition?
Yes, it does.
5. Are the discussion and conclusions well balanced and adequately
supported by the data?
Can the authors explain how the differences in healthcare access
(unless IS in one area is not seen by medical personnel and thereby
missing the diagnosis) and patient management are likely to play a role
in the country specific incidence rates?
6. Are limitations of the work clearly stated?
Yes.
7. Do the authors clearly acknowledge any work upon which they are
building, both published and unpublished?
Yes.
8. Do the title and abstract accurately convey what has been found?
Yes.
9. Is the writing acceptable?
Certain areas can be improved:
A. Children under 2 years of age representing potential IS cases were
enrolled in 16 centers in 11 Latin American countries from January
2003 to May 2005
B. If definite criteria is not fulfilled, various combinations of major and
minor clinical criteria may define cases as probable IS, possible IS
and suspected cases of IS with insufficient evidence (Table 1).
C. Of the 168 children undergoing conservative primary treatment
(enema and/or ultrasound), 76 (45.5%) did not undergo secondary
surgery. Does the primary treatment includes baruium and air
reduction rather than ultrasound?
D. To ensure that the study procedures conformed across all
investigator centers add to limit potential under-reporting, the
study protocol, case report form and safety reporting were
reviewed with all investigators and other personnel responsible
for the conduct of the study prior to study start and at regular
interval periods.
Major Compulsory Revisions
1. Needs to clarify whether the surveillance and clinical trial were carried out
at the same time. If so, the aim to describe the epidemiology and to
estimate the incidence of IS in Latin American infants prior to new vaccine
introduction is not valid.
2. To explain or justify the statement that the differences in healthcare access
and patient management are likely to play a role in the country specific
incidence rates?
Minor Essential Revisions
To clarify the statement 'conservative primary treatment (enema and/or
ultrasound)'. Normally, one uses barium or air enema rather than ultrasound to
treat IS.
Discretionary Revisions
To add title to the actual Figures.
.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Needs some language corrections before being
published
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I had participated, up to 2010, in research projects where GSK is the sponsor.
Other than that I declare I have no competing interests.