Reviewer's report
Title:The Confidence and Trust in Delivery Questionnaire (CTDQ): A pilot
validation study.
Version: 1Date:21 March 2011
Reviewer: Heather Rowe
Reviewer's report:
This article reports on the development and preliminary validation of a German
language self-report questionnaire for assessing “confidence and trust” in the
forthcoming delivery in expectant mothers. However there are a number of
conceptual, methodological, analytical and interpretative matters that require
attention prior to publication.
Minor essential revisions and major compulsory revisions
The question posed by the authors requires further justification.
1. Introduction: There is no doubt that confidence in caregivers and feelings of
being involved in decision making during labour are important components of a
woman’s appraisal of her experience of labour. However the authors do not
provide a sufficiently coherent argument about the value of assessing these
constructs prior to the birth. Who would use such a measure? How would the
score be used? What is the proposed mechanism for the link between use of the
questionnaire and improved childbirth outcome for women who complete the
CTDQ?
2. The authors list four existing validated measures that assess similar
constructs. However they do not provide sufficient information to describe the
specific limitations of these measures, why the proposed new measure is needed
or what it will add. Why is confidence and trust in delivery an important construct
in pregnancy? What is the value of assessing these constructs prior to birth? Are
women’s levels of confidence and trust modifiable? How might this be achieved?
Why might it be worthwhile? What is the evidence that changes in these
constructs will improve childbirth experience?
3. Materials and Methods: Please describe the “methodologists” in more detail
and what they contributed to the expert panel.
4. Was approval from a properly constituted ethics committee obtained? Please
state the name of the committee and the date of approval.
5. More details about recruitment are required: Who invited women to
participate? How were women invited? Was recruitment consecutive? Or
according to convenience? Were signed consent forms completed? Who
performed the “comprehensive counselling session? Some of the questions elicit
sensitive information. Where were the questionnaires completed? In private,
public, at home? How were the questionnaires returned to researchers? By post?
In person?
6. Data collection: Questionnaire #3 needs more explanation. Please spell out
SOC acronym and provide a rationale for the use of this scale for the purpose of
validation of the CTDQ. How are the psychological constructs measured in the
two scales related? Why is the SOQ a suitable external validation standard for
the CTDQ?
7. Similarly Questionnaire #4. The VAS rates “pain level”. It is not clear whether
this is current pain, expected pain, or pain in a previous delivery. The authors
need to justify why this is a suitable measure for external validation of the CTDQ.
8. Results: Please state recruitment fraction (221/318 ~70%). Provision of
comparison sociodemographic data in Table 1 would assist the reader to assess
representativeness of the sample. Please provide where possible. A comment
about lack of representativeness is made by the authors in the Limitations
section, but data on which this assertion is based should be provided.
9. Dimensions and internal reliability of CTDQ: The authors assert that the
factors have clinical as well as statistical relevance. Please state what this is here
(eg The factors are interpretable? Meaningful? Are consistent with women’s own
descriptions of what is relevant to them?) and elaborate further in the Discussion.
10. 3rd para of this section: Please provide a reference for the statement that ….,
item-total correlations are in the optimal range……”
11. External validity: This section requires further elaboration. For example a
description of the specific psychological constructs that are (and are not)
correlated, and the distinction between positive and negatively correlated scale
scores. Please provide an overall statement of the strength of evidence for the
external validity of the CTDQ questionnaire provided by these data.
12. Discussion: Para 2: It is not clear that the authors’ conclusions are supported
y the data. Rather than ”clearly indicat(ing) that the core aspects of trust and
confidence in labour are captured….”, the four-factor solution result might
suggest that “confidence and trust in delivery” is not a unitary construct, but
rather a set of items, each of which has its own independent meaning. Similarly it
is not clear whether the evidence for the independence of the CTDQ from the
SOC and “pain perception” measures suggests that the CTDQ is measuring
something meaningful or not. The results provide evidence for what the scale is
NOT measuring rather than for what it IS measuring. Some acknowledgement of
these matters is required n the discussion.
13. Para 3 is unclear. Please re-phrase to make the meaning clear.
14. Para 5: The authors appear to be making a case for the use of the CTDQ as
a “screening instrument” for women who will go on to have a traumatic delivery.
However, the practical implications of its use for this purpose require further
elaboration.
15. Final para: The points that the authors are making about the lack of
association of the CTDQ and the SOC and pain intensity measures are unclear.
This paragraph would benefit from re-phrasing to improve clarity.
16. Limitations: The authors acknowledge that the sample includes women of
mixed parity. It could be argued that prior experience of labour would have an
impact on a women’s expectations of childbirth and therefore on the results of the
study. Please provide some elaboration on the nature and magnitude of effect
that this might have exerted on the results of the study.
17. Conclusion: The authors state that the CTDQ is “well accepted”. Whilst this is
likely to be the case no data are presented to confirm that women or clinicians
found it acceptable or easily completed. Again, the authors state that the CTDQ
is useful, but do not explain how or when the CTDQ might be used, what clinical
or research utility it might have, what might clinicians do when women score high
or low, what dimensions could be modified, how this might be achieved, why this
might be beneficial, or what risks might be associated with its use.
18. The writing is acceptable with the exception of some instances where
re-phrasing would improve clarity (see above).
Minor issues not for publication
• Background para 2 line 9: extend should read extent
• Questionnaire Item 8/Table 2: Please consider whether obstetrician be a better
English translation than gynaecologist?
• Data collection: Questionnaire #2 please spell out EA
• Table 1: ;meaning of MW should be spelt out. It is not a universally understood
abbreviation for mean.
• Table 3 Partners support should read Partner’s support; Add ** p=.05(?)
• Discussion line 1 aims should read aimed
Level of interest: An article of limited interest
Quality of written English: Needs some language corrections before being
published
Statistical review: Yes, and I have assessed the statistics in my report.
Declaration of competing interests:
I declare that I have no competing interests