Reviewer's report
Title:Prevalence and Risk Factors for Inter-Generational Sex: The Transactional
and Inter-Generational Sex (TIGSex) Survey of Barbadian Females Aged 15-19
Version: 2Date:16 August 2013
Reviewer: Neil Andersson
Reviewer's report:
Major compulsory revisions:
1. Justify ignoring clustering, or redo analysis taking clustering into account.
2. Shorten discussion and strengthen section on limitations
Other comments
1. Is the question posed by the authors well defined?
- The question is original in Barbados, important and well defined. The study is
limited to female youth, the pivotal group in HIV generalised epidemics.
2. Are the methods appropriate and well described?
- The cross-sectional design chosen by the authors is perfectly adequate for this
stage of the enquiry
- The statistical analyses is broadly appropriate although makes no allowance for
multiple testing or clustering. There is only so much one should be tempted to do
with a data set of nearly 100 information items and 46 people in the index group
– there are probably around that number of significance tests in this paper.
- The sample: choosing every fifth household within 16 randomly selected polling
districts means the data cannot be treated as a simple random sample,
especially if “all eligible girls within each household were selected for inclusion in
the survey” (p8). This is a cluster sample (by polling district and household) and
results should ideally be adjusted to reflect that. At very least, a note might
explain why they ignore clustering.
3. Are the data sound?
- In general, it seems like a well conducted study.
4. Does the manuscript adhere to the relevant standards for reporting and data
deposition?
- The reporting is adequate if not STROBE level (does BMC Women's Health
require STROBE reporting?).
5. Are the discussion and conclusions well balanced and adequately supported
by the data?
- The discussion is repetitive (first and second para say the same thing)
- This section runs at about 1500 words, fully 1/3 of the overall article. That could
probably be reduced to 750 words without losing core content. The interpretation
stretches the limits for the size and design of the study. The detailed speculation
is interesting but not indispensable.
- The limitations are under-emphasised.
6. Are limitations of the work clearly stated?
- This is a weak section of the discussion.
- The authors could acknowledge the limits of cross-sectional studies and the
assumptions they make about directions of causality (eg self esteem and not
attending religious service could conceivably be a consequence of forced sex or
IG sex).
- Little is made of the fact that these data come from face to face interviews; the
associated multiple biases are not really faced in this section or elsewhere.
7. Do the authors clearly acknowledge any work upon which they are building,
both published and unpublished?
- The study is well situated in the literature, international and regional.
8. Do the title and abstract accurately convey what has been found?
- the title is a bit immodest. “The TIGSex survey” is not an entity of any renown.
Why not just call it “Prevalence of and Risk Factors for Inter-Generational Sex: A
cross-sectional cluster survey of Barbadian female youth aged 15-19 years”
- This inappropriate branding runs insistently through the article, referring
unnecessarily to “TIGSex respondents” and “reported by TIGSex...” -- 10 times in
the course of the article. I can't help feeling this quest for immortality detracts
from what seems otherwise to be a good little study.
9. Is the writing acceptable?
- This is a small study with a LOT of significance testing: 261 young people in 16
clusters; the least the authors can do is to mention n= on EVERY occasion they
use a %, and state negative findings with a degree of modesty.
- Given the study size, the authors could be more cautious where they failed to
show an association: “We could not confirm...” “we could not demonstrate...”
would be more decorous than “there was no association...”
- The persistent use of passive voice makes for difficult reading
- Some unnecessary complexities could be reduced (for example, page 19
second para, ratio of 2/3 to 1/3. Isn't this the same as 2:1?
- Abstract: The abstract could do with some work. move methods (from
Introduction) into methods
10. Are the data presented in the most appropriate manner
- Table 3 and Table 4 show p-value AND confidence intervals. the p-value is
redundant
- I learned little from the figures and would probably find the article equally
informative without them.
Level of interest: An article of importance in its field
Quality of written English: Acceptable
Statistical review: Yes, and I have assessed the statistics in my report.
Declaration of competing interests:
I declare that I have no competing interests