Review for 10.1186/1471-230X-11-126 (2011)

Reviewer's report
Title:Development of a validated Patient Reported Symptom Metric for Pediatric
Eosinophilic Esophagitis: Qualitative Methods
Version: 1Date:21 July 2011
Reviewer: Emuella Flood
Reviewer's report:
This paper described the development of the PEESS version 2.0, a
patient-reported symptom assessment tool for children with EoE. Given that the
PEESS version 1.0 was developed without patient input, a key step in developing
patient-reported outcomes, the authors performed concept elicitation interviews
with patients and parents to identify any missing content and to draft the PEESS
version 2.0 instrument. Cognitive interviews were then conducted to address
issues with understanding and interpretation, and revisions were made based on
these results.
General Comments:
The authors should note that this is not the first study to assess content validity of
patient and parent-completed symptom assessment tools or EoE. See Flood et
al., Patient and caregiver perspective on pediatric eosinophilic esophagitis and
newly developed symptom questionnaires. Curr Med Res Opin. 2008
Dec;24(12):3369-81. Additionally, with respect to symptom assessment tools,
there is a general move toward daily assessments through electronic diaries, at
least in the trial setting. The one-month recall period is of particular concern. And
finally, per FDA, parent proxy tools are generally not accepted. Parent observer
tools are accepted, but the items can only be symptoms that would be clearly
observed by the parent. Pain, for example, would not be included in a parent
observer tool.
Discretionary revisions
1. Consider replacing “focus interviews” with “concept elicitation interviews”,
which is now the commonly used term in PRO research
Major compulsory revisions
Abstract:
2. Objective should be clarified. As I understand it, your objective was to assess
the content validity of the PEESS and revise it based on patient and parent input,
thereby establishing its content validity.
3. Results section seems to include methods and conclusions and few results.
Second-to-last sentence describes the methods. The last sentence is more of a
conclusion. I would recommend that you report what the patients told you about
symptoms and the specific changes you needed to make after cog debriefing.
Background:
4. First paragraph, last sentence. Not accurate per above.
5. “Proxy” should be replaced with parent “observer” throughout. As noted above,
proxy measures are not acceptable by FDA. Only symptoms that the parent can
observe should be included in the measure (ie, a parent cannot assess pain, or
difficulty swallowing, etc. Only things like vomiting, trouble sleeping, etc., should
be included.)
6. Clarify the objective as noted above. Are you developing a new PRO or
assessing content validity of an existing PRO and updating it based on your
findings?
Results:
7. Need a description of the sample – number per age group, males/females, etc.
8. More details on concept elicitation results would be useful. What symptoms
were reported and how frequently? How were they described by children? Which
ones were considered most severe or most troubling? What symptoms were
missing from PEESS v1? Any differences by age group: 8-12 vs. 13-17?
9. Sample size could be considered low, particularly given the age range and
variability of symptoms. Did you reach information saturation? Assessment of
saturation should be added.
10. Recall period is of particular concern. One month is quite long, particularly for
children, and in trials, symptoms are generally assessed in a daily diary format
with a 24-hour recall period. Was recall explored during cognitive debriefing? If
so, results should be included. Do you have a rationale for a one-month recall
period?
11. There is mention of a VAS, but the graphic doesn’t seem to have a VAS. Do
children provide their responses using a VAS?
12. If you do not want to include the measures themselves, a more detailed
description of the final versions of each would be useful – X items covering the
following symptoms, scored on a Likert? VAS? scale, etc.
Discussion:
13. Discussion is a bit lean. Would add reference to Flood et al and compare
findings with respect to symptoms assessed in the respective measures. Also
perhaps discuss differences by age, if any exist.
14. Need to add study limitations.
Level of interest: An article whose findings are important to those with closely
related research interests
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.