Review for 10.1186/1471-230X-11-110 (2011)

Reviewer's report
Title:Feasibility and cost-effectiveness of internet-based exposure treatment for
irritable bowel syndrome in a clinical sample: a randomized controlled trial
Version: 3Date:17 July 2011
Reviewer: Yanda van Rood
Reviewer's report:
The authors have rewritten the manuscript completely and they have answered
the points sufficiently well. However, as the authors state in their final sentence in
reply to the reviewers “…major rewriting … always raises new questions …”
Indeed some major compulsory revisions (MCR) and minor but essential
revisions (MER) still need to be addressed.
MCR
Firstly, the authors are advised to let their manuscript be corrected for English
style and specifically pay attention to the phrasing of sentences and use of
commas. The authors use the personal style (‘we’ / ‘our’ ) often (39 /29 times)
also in parts of the manuscript were a impersonal (academic) style is expected
(methods, analysis and results).
Furthermore, the background and discussion are very long and they both need
structuring; i.e. a paragraph per subject and subjects logically following from
each other. This would improve reading and lead to a reduction of the number of
words since at a number of occasions the authors repeat themselves.
MER: The title includes feasibility and cost-effectiveness but effectiveness is
missing from it.
MCR: In the method section the authors describe how they study effectiveness
and cost-effectiveness but feasibility is not defined. Instead of feasibility the
authors might want to focus on acceptability instead since acceptability and
compliance seem more relevant aspects of the study than feasibility.
Acceptability and compliance to the treatment regime were low as is suggested
by the high dropout rates (also before randomization) and the fact that only 43%
of the patients worked through all the steps of the program.
MER: In the method section, e.g. treatment condition, background information is
given that might be better placed in the background section.
MER: In the analysis section the authors describe that they used all available
data on the assumption of MAR; i.e. missing at random. However, one might
question the randomness of the missing data especially since the data itself give
the impression that the missing of data might be associated with lower
acceptability and/or compliance to treatment of patients with more severe IBS
complaints. The authors might want to describe how this assumption was tested
or made plausible.
DR: Results. The intervention is aimed at breaking the vicious circle by reducing
anxiety and avoidance behaviour. Pearson correlations between the change
scores of IBS symptoms and anxiety and avoidance measures, would give some
insight in the relation between these two aspects and mechanisms that play a
role in the reduction of IBS symptoms (mediators).
<ER: Page 9 first sentences Figure 1 needs to be Table 1. Please check, on 11
occasions Figure is used, were in some instances Table is meant.
DR: In the discussion the authors should present firstly the results concerning
feasibility (or better acceptability), effectiveness and cost-effectiveness before
discussing them. Furthermore, in the discussion the authors might want to refer
to other studies as well as to their own previous study. Specifically studies
showing that certain interventions are most suited for patients with less severe
symptoms.
DR: The results suggest that this specific ICBT intervention is best suited for
patients with less severe IBS complaints, anxiety and avoidance behaviour. In
the discussion the authors might want to bring forward that the intervention could
be a offered as a first step in a stepped care approach and could best be offered
to patients in primary practice who have generally less severe complaints than
patients visiting an outpatient GE clinic. These patients are probably also more
like the self referred and specialist referred patients from the earlier study.
DR: The effect-size observed in the earlier study was large, the effect-size in the
current study was moderate. “Somewhat larger” does not accurately describes
the difference.
Level of interest: An article of limited interest
Quality of written English: Not suitable for publication unless extensively edited
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
'I declare that I have no competing interests'