Reviewer’s report
Title: 
Can TSH level and premenstrual spotting constitute a non-invasivemarker
for the diagnosis of endometriosis?
Version: 
0 
Date: 
11 Jun 2021
Reviewer's report:
Dear authors,
I congratulate you on the effort. However, I identify several points that need to
be revised to make the study reproducible. In this way, the interpretation can be
generalized.
# Limitations
# The hypothesis is weakly supported by the literature presented.
# Serum TSH level varies considerably throughout the day. I don't know if there
is a pattern in the collection, especially in a retrospective study.
# Characterization of the sample is poor. What is the stage of endometriosis?
Were only patients with infertility included? And pain? Were women with
infection or other infertility factors excluded? The impossibility of knowing
exactly the stage of the disease seriously compromises the interpretation.
# How was the sample size calculation done? In my view, the number of patients
included is very low and, consequently, the power of the test is very low.
# Authors included patients using levothyroxine. This can bring a great bias to
the study because the patient may have a suppressed TSH value, even if the
value changed in a baseline measurement without medication.
# Categorizing a continuous variable such as TSH level means loss of
information. I recommend using continuous data in a suitable statistical model
with regression.
# The definition of 'spotting' used by the authors also does not seem the most
correct and/or comprehensive. What is the reference for this use?
# Why were patients with visible disease excluded?
# Did the authors lack information on dysmenorrhea in the population of women
with endometriosis in 20% of cases?
# The statistical analysis presented is not adequate.
# Results: format tables properly. Use only lines above, below, and below the
header. Avoid lines between variables and vertical lines. There is no need to say
yes and no. Use only one way to avoid redundancy. I recommend using only one
decimal place for variables of type 'float'. Choose the median and interquartile
range if the distribution is not normal. In these cases, avoid the mean and
standard deviation as measures of central tendency and dispersion. Tables 3, 4
and 5 incorrectly express values. The ideal would be to at least perform a logistic
regression analysis and assess the independent influence of the factors.
Publons Reviewer Recognition
. Springer Nature can send verification of this
review directly to Publons (a subsidiary of Clarivate Analytics). If you would
like to take advantage of this service, please click on the “Yes” option below.
Your name, email address, title of the reviewed manuscript, name of the journal,
and date of your review submission (the “Review Data”) will then be transmitted
to Publons after the final decision on the manuscript has been made. If you have
already registered at Publons, they will notify you of the receipt of this review
and update your profile 
as per your settings and their policy. If you are not
registered with Publons, you will receive an email from them asking you to
register in order for them to be able to recognize your review on your new
profile page. Publons may use the Review Data to generate derivative metadata
for the benefit of Publons and you as a reviewer, carefully considering the
sensitivity of such information. For example, Publons may verify your record as
a reviewer by updating your profile published on its webservice if you have
registered for such service or help editors to identify candidate reviewers. Please
find the details of processing in Publons’ privacy policy
https://publons.com/about/terms
Yes
Declaration of competing interests
Please complete a declaration of competing
interests, considering the following questions:
1
. 
Have you in the past five years received reimbursements, fees, funding, or
salary from an organisation that may in any way gain or lose financially
from the publication of this manuscript, either now or in the future?
2
. 
Do you hold any stocks or shares in an organisation that may in any way
gain or lose financially from the publication of this manuscript, either now
or in the future?
3
. 
Do you hold or are you currently applying for any patents relating to the
content of the manuscript?
4
. 
Have you received reimbursements, fees, funding, or salary from an
organization that holds or has applied for patents relating to the content of
the manuscript?
5
. 
Do you have any other financial competing interests?
6
. 
Do you have any non-financial competing interests in relation to this
paper?
If you can answer no to all of the above, write 'I declare that I have no competing
interests' below. If your reply is yes to any, please give details below.
I declare that I have no competing interests.
Reviewer Publication Consent.
 I agree for my report to be made available
under an Open Access Creative Commons CC-BY License (
http://creativecommons.org/licenses/by/4.0
) if this manuscript is accepted for
publication. Any comments that I do not wish to be included in the published
report have been included as confidential comments to the editor, which will not
be published.
If you are not happy for us to publish this report, please contact the
editorial office before completing the review.
If you wish, you can include your
name in your published report. Please note you must decide whether to include
your name at the start of the process and confirm this decision whenever
prompted. If you change your decision later, we will not be able to publish your
name.
I agree to the terms of the CC-BY 4.0 license; please 
do not
 publish my name
with my report. (default)
Is the study design appropriate to answer the research question (including the use
of appropriate controls), and are the conclusions supported by the evidence
presented?
No
Are the methods sufficiently described to allow the study to be repeated?
No
Is the use of statistics and treatment of uncertainties appropriate?
No
Is the presentation of the work clear?
No
Are the images in this manuscript (including electrophoretic gels and blots) free
from apparent manipulation?
Yes