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

Reviewer's report
Title:Delivering internet-based exposure treatment for irritable bowel syndrome
in a clinical setting: a randomized controlled trial.
Version: 1Date:14 March 2011
Reviewer: Melissa Hunt
Reviewer's report:
This manuscript, titled “Delivering internet-based exposure treatment for irritable
bowel syndrome in a clinical setting: a randomized controlled trial” is a nice
extension/replication of the authors previous work on their ICBT intervention for
IBS (16 in their references). The question posed by the authors is well defined –
namely will the intervention work (i.e. be “effective”) in a representative clinical
sample of IBS patients (as opposed to a screened or self-referred sample). The
methods used are appropriate and well described. The data appear to be quite
sound. Indeed, they have used a sophisticated set of appropriate outcome
measures that go well beyond the ludicrously inadequate single question binary
outcome measure of “adequate relief” used in most pharmacological intervention
studies. They have also used a sophisticated data analytic strategy that is
appropriate for the sort of data they have. The introduction is thorough and
reviews the prior work on which they are building. The discussion and
conclusions are well-balanced, adequately supported by the data, and clear
about the limitations of the work. The abstract, however, is MISSING, and needs
to be added to the ms. The writing is acceptable and indeed the ms is better
written than many by American and British authors.
There is only one discretionary revision that I would like to see: the authors point
out that their effect sizes were lower than in their own previous trial, but they do
not make any effort to calculate or report on the clinical significance of their
findings. This is particularly important given the nature of the sample. They point
out that the mean baseline scores on the VSI and the IBS-QOL were “markedly”
less severe than in prior physician referred or self-referred samples. It would be
quite interesting to know several things. First, what percentage of the entire
sample achieved clinically significant symptom reduction. Second, if you divide
the sample into more and less severe groups (based simplistically on a median
split, or better on 1 SD below the mean of the symptom inventories from their
prior study) would the percentage of individuals achieving clinically significant
change look dramatically higher for the individuals who were more impaired to
begin with? That is, simply giving us group means and effect sizes for treatment
versus control doesn’t give us enough detail about actual symptom change
across the range of patients enrolled.
The authors conclude, rightly, that we need more research on which to base
recommendations about which IBS patients stand to benefit from receiving
psychological treatment. Ironically, they may have data from this study which
speaks to that point but which they have not fully exploited. In the US, at least, it
is very difficult to get gastroenterologists to refer for psychological treatment at
all! If we had clear cut clinical guidelines that could foster a better referral
pipeline, all the stakeholders would benefit.
Level of interest: An article of importance in its field
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests