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:30 August 2013
Reviewer: Anne Cockcroft
Reviewer's report:
This is a useful study about an important topic, particularly in relation to HIV risk.
Major compulsory revisions
1. Analysis. It seems that the authors have adjusted the bivariate associations
found between several factors and the outcomes of (a) having had sex and (b)
having had IG sex (among those who have ever had sex) only for age. But some
of the bivariate associations might be explained when the effects of the other
variables associated with the outcome are taken into account in a multivariate
analysis. The authors should undertake a suitable multivariate analysis. I realise
that their ability to do this might be limited because of the relatively small
numbers in their sample (261 young women in total, and 132 who have ever had
sex). But they should attempt it.
2. Analysis. It is not surprising that the authors demonstrated associations
between the measures of self-esteem, sense of personal power and perceived
peer pressure. The scatter plots are not really helpful or relevant to the point of
this article, however, and could be left out. It could be relevant for the multivariate
analysis recommended above that these factors are associated with one another.
3. Interpretation of associations. Conclusions about causality from a
cross-sectional study should be very cautious. In a cross-sectional study it is not
possible to determine the direction of associations. For example, low self-esteem
might be a reason for early sexual experience or for involvement in IG sex. On
the other hand, early sexual experience and involvement in IG sex might be a
reason for having low self-esteem. Either or both processes might be operating.
The authors should avoid statements like “Low self-esteem is a common driver
for IG-sex and sex with any partner” (Abstract p3) which imply causality. They
should include an acknowledgement about the limitation of interpretation of
associations in cross sectional studies in the paragraph in the discussion on
Limitations.
4. Transactional sex. The rate of transactional sex (55%) is extraordinarily high.
The authors do not give details of the question or questions they asked to
estimate transactional sex, nor do they give a time frame. Is it possible that their
questions could have included gifts from boyfriends that would not normally be
counted as transactional sex? I realise that the dividing line is blurred, but gifts
such as a bunch of flowers or a box of sweets on a date would not usually be
counted as transactional sex. What question or questions did the authors use to
determine involvement in transactional sex? What was the time frame? Was it
“last 12 months” or “ever”? The authors should include these details in the
Methods and Results. They should comment in the Discussion section on the
very high rate of transactional sex they found and discuss this in light of results
from other studies.
5. Tables.
a. Table 1. Add a column on the right with totals.
b. Table 2. It is not clear why there were quite a few missing responses for the
question about IG sex within the last 12 months (234/261 responded among all
the young women and 107/132 responded among the young women who had
ever had sex). This is a missing data rate of 10% among all young women and
19% among young women who had ever had sex. This could affect the
estimated rate of IG sex in the last 12 months. For example, if none of those with
missing data had IG sex, the rate would be reduced to 23.4% (31/132). The
authors should explain and comment on this missing data.
c. Table 3. Expand the title to make it clear the outcome was “ever having had
sex” among all the young women.
d. Table 4. The title is misleading. The analysis in this table is confined to young
women who had ever had sex.
Other revisions
6. In the Abstract it would be helpful to mention rates of IG sex among all the
young women as well as among those who had ever had sex.
7. References. There are a large number of references (86). In many places, the
authors cite multiple references to support the same point. The authors could
consider reducing redundant references.
8. In several places in the text, the authors do not make clear that the rates
quoted are among sexually active respondents; they should go through the text
and add this information where relevant.
9. The authors use the passive voice throughout. These days, most journals
recommend using mainly the active voice. The authors should consider
re-casting the text into the active voice as far as possible.
Level of interest: An article whose findings are important to those with closely
related research interests
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