Reviewer's report
Title:Menstrual bleeding patterns: a community-based cross-sectional study
among women aged 18-45 years in Southern Brazil
Version: 1Date:10 August 2010
Reviewer: Sioban Harlow
Reviewer's report:
This paper reports on the prevalence and correlates of heavy menstrual bleeding
in a Brazilian community based study. Few data are available in this population
and careful attention was paid to obtaining a community based representative
sample. However, insufficient attention is paid to biological differences in uterine
bleeding profiles by type of contraception. As only 40% of the study sample is
menstruating in the absence of IUD use or hormonally-mediated endometrial
bleeding, the authors need to reconceptualize and retitle their paper to reflect this
conceptual difference between ‘heavy bleeding” in the context of menstruation
versus hormone or IUD use. Except for the finding on low education, the paper
does not add new information on the correlates of heavy bleeding.
- Major Compulsory Revisions
1. The approach for measuring amount of blood flow is innovative, however, it is
not obvious how valid the approach is or how grams of water compare to units of
blood loss. For example, how many grams of water would correspond to the
quantitative definition of menorraghia? Considerable work has been done on
estimation of amount of blood from reporting of sanitary pad data (additional
citations -- Higham JM, O'Brien PMS, Shaw RW. Assessment of menstrual blood
loss using a pictorial chart. Br J Obstet Gynaecol. 1990;97:734–739)
How does your approach compare to these approaches? A key difference is that
these approaches all consider how full the pads were at the time of changing.
Does your approach really add information over the number of pads or the
frequency of changing pads or the number of super or regular pads. More needs
to be presented in the methods about the validity of this measure. Are multiple
types of pads available to this population?
Also your use of this pad-water weight measure is used solely to argue the
validity of the self-reported intensity of flow. Its presentation in methods and
results should reflect that fact clearly. Please also show distribution of
water-weight by flow amount (eg side by side box plots) so the overlap in values
can be assessed. Although the discussion section discusses these issues at
length, the attention in the discussion in contrast to the main results is not well
justified.
Consider justifying the need to assess correspondence of self report with pad
use in this population. Clarify reasons for using your approach over pad count.
2. 5 days of bleeding is within the range of normal, please report % greater than
7 or 8 or 10 to reflect data more consistent with a definition of “long” potentially
“abnormal” menses.
3. Further exploration of the low education finding is warranted. To what extent
might this finding reflect older age, bmi, or anemia. Is there a possibility of
residual confounding. Is there any evidence of differential reporting/sanitary
product use by very low education. Might contraceptive utilization differences
account for this difference.
4. Given the known impact of hormonal contraceptives (reduce flow and/or
intermenstrual bleeding) and IUD (what type is used in this population? Types
that increase blood flow or types that reduce blood flow?) on blood flow please
present results stratified by contraceptive use type (hormonal (pill + injection),
IUD and none/barrier/tubal. After viewing the stratified results it may be possible
to consider a single regression with interactions, but the data as presented here
to not give this reviewer confidence that the implications of contraceptive use on
bleeding has been adequately considered.
5. DISCUSSION – the discussion should begin with a summary of the major
findings and contributions of the paper, not with a series of limitations. Start the
discussion with the first full sentence on page 11. The main new findings relate to
prevalence in this population (not previously reported) and increased prevalence
in women with little education.
6. In table 3 – clarify what is included in the adjusted model.
7. Given the difference between heavy, normal and very heavy, abnormal
amounts of blood flow (and long normal versus abnormally long duration of flow),
please try to clarify more precisely in your methods, results and discussions
whether your paper addresses heavy normal flow or abnormally heavy bleeding.
Discuss implications of blood flow in the presence of contraception.
8. The discussion can be written more concisely, should present major findings
including findings in context of contraceptive users and barrier/non-users,
followed by comparison to other literature, discussion of validity study (if
retained), discussion of limitations, and major conclusions.
- Minor Essential Revisions
1. “alfa” should be “alpha”
9. Page 5 second to last line == “cranial” is not the correct word here. It is not
clear what you mean.
10. “no-response” should be “non-response”
11. Page 7 “average number of formal” should be “average number of years of
formal”
12. Page 8 it is “surgical”
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 I have no competing interests