Review for 10.1186/1471-230X-8-25 (2008)

Reviewer's report
Title:Quality of health care and patient satisfaction in liver disease: the
development and first results of the QUOTE-Liver questionnaire
Version: 2Date:24 March 2008
Reviewer: Andrew M Garratt
Reviewer's report:
Major compulsory revisions
Overall I am pleased with how the authors have addressed my previous
concerns. One important issue remains though which relates to the results of
principal components analysis (PCA) and how this informs item selection. The
results suggest that three items do not contribute to the interaction/contact with
the physician construct. Hence it is incorrect to simply add these three items to
the other 17. They also have low item-total correlations, one being very low at
0.08. The alpha is quite high but this is only to be expected with so many items. I
am unsure if the QUOTE item summation process outweighs these concerns but
this is something that needs to be addressed. The authors should give
consideration to previous QUOTE work but also to the use of PCA and factor
analysis in the context of decision making relating to item removal within patient
experiences/satisfaction questionnaires and patient-reported outcomes more
generally.
Minor essential revisions
1. In the fourth paragraph of the Background the authors use the term “state of
the art” which I do not consider to be very scientific. I would like to see this term
removed.
2. Slightly further down the page it is stated that “the majority of researchers have
now distinguished these two basic components of patient (dis)satisfaction. Is a
single reference enough here? “Distinguished” is rather vague but given that the
majority of patient experiences/satisfaction instruments do not measure
importance I suggest removing this sentence.
3. I do not feel that the authors adequately justify their use of a four-point
descriptive scale. They do not provide adequate references. Nor do I feel that it
will be possible to justify it using an adequate literature review. When the authors
refer to a Likert scale, are they referring to five-point descriptive scales in general
or a five-point agree-disagree all-point descriptive scale, what is known as a
traditional Likert scale? There is some general evidence to support their
assertion in relation to the latter but one would expect more positively skewed
data with four-point scales than five point scales that use the same end-points.
There has been considerable testing relating to the performance of different
scale types but due to contextual factors generalisability is often limited. So
unless they have specific evidence relating to a comparison of importance ratings
using five- and four-point scales from the QUOTE work I suggest that they simply
state that they have followed the QUOTE family approach to item scaling.
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 declare that I have no competing interests.