Reviewer ’s report  
 
Title:  One in five women suffer from pelvic floor disorders in Kersa district Eastern Ethiopia: A 
community -based study  
 
Version: 1 Date: 05 Mar 2018 
 
Reviewer:  Marlene  Egger  
 
Reviewer’s report:  
 
General comments: This paper established the prevalence of certain pelvic floor disorders among 
ever-married women in the Kersa district of Eastern Ethiopia. A strength is that it is the first 
large scale, community -based study to address this in Ethiopia.  Another strength is the authors' 
translation -back -translation of the pelvic floor disorders questionnaire. Another strength is that 
they point out the effects of the age pyramid in different countries on the rates of PFDs: the more 
older women in the stud y/country, the higher the expected cross -sectional prevalence rates.  
 
Although this is an important topic, and the high prevalence of pelvic floor disorders is an 
important finding requiring policy recommendations, some of the methods are troubling.  
 
 
Speci fic comments:  
 
1. This study was restricted to ever -married women. Yet never -married women and 
nullipara can have prolapse and other pelvic floor disorders. This would bias the 
prevalence rates upward, since never -married women and nullipara are excluded. T his 
should be discussed and compared to the methods used by the other studies that the 
authors reference.   
 
2. The authors say that enrollees were selected by a multistage stratified random sample, 
enrolling one ever -married woman at random per household (p. 4 l. 12.) It is not clear 
whether they re -visited households with questionnaires for the current study or whether 
the data were collected at the same time as the rest of the Kersa HDSS. They say on the 
same page that they used the Kersa HDSS database a s a sampling frame and on p. 6 in 
the data analysis paragraph that they calculated a simple, unweighted prevalence. They 
should clarify the sampling procedure and explain whether/why they did or did not use 
sampling weights in the Stata analysis.  
 
3. The authors reference the Lukacz EPIQ questionnaire, although they are careful not to 
say that they used the EPIQ. One of the strengths of the EPIQ as originally developed and 
validated is its VAS scale; another is its criterion validity relative to a clinicia n's 
diagnosis. Literature on instruments addressing other conditions, e.g., pain, shows that 
while a numeric rating scale may be repeatable, it can be biased relative to a VAS version 
of the same instrument. Also, a numeric rating scale is not a ratio meas ure, whereas some 
papers have reported that a VAS scale is a ratio measure.  In fact, the authors did not use 
the EPIQ's VAS scale, but altered the instrument instead to use a 1 -4 bother scale, which 
is then re -weighted to a 0? 25? to 100 scale, similar to  the one in the PFDI/PFIQ. 
However, the present authors did not re -validate their instrument statistically, and this is a 
significant weakness.  
 
Technically, an instrument is considered reliable and valid when used in the same way that it was 
used when it  was validated. The PFDI/PFIQ (to which the authors refer) was validated using a 0 -
4 scale (0 means they don't have the condition; 1 means they have it but there is no bother) 
transformed by multiplying by 25. The EPIQ was validated using a VAS scale. Thus , in order to 
use the EPIQ as the present authors have adapted it, they would have to do new studies to 
determine its reliability and validity. The authors have provided no information about the 
reliability and validity of their adaptation of the EPIQ, nor  did they provide a rationale for not 
using the VAS scale. Thus, the authors have used an instrument that has not been validated.  
 
How much this would affect prevalence rates is unknown, and in part it depends on exactly how 
the authors altered the EPIQ. Is there still a stem question, where the interviewee must respond 
yes/no to a symptom, followed by a separate question about bother? Even if there is still a stem 
question, one might hypothesize that prevalence rates will be similar to those obtained with  the 
original EPIQ, but to be certain, re -validation is required.  
 
Comparison of VAS scales and numeric rating scales for other conditions suggests that the 
altered severity of distress/bother cannot be considered comparable to bother measured on a 
VAS sca le. They authors re -categorize severity of distress as mild, moderate, or severe, p. 6 l. 
19, p. 7 l 21, and in figure 2; but they have not defined these categories numerically. They should 
provide a definition of these categories.  
 
If the authors had a go od reason to alter the EPIQ the way that they have, they should note it in 
the Discussion and comment that future studies are required to re -validate this altered instrument, 
and that the mild, moderate, or severe categories used in this paper cannot be re ferenced to 
similar categories used in validated instruments. Better yet, they could perform this re -validation 
and then this paper would be much stronger.  
 
4. There appears to be a phrase missing between p.10 l. 22 and p. 11 l.1.  
 
Are the methods appropriat e and well described?  
If not, please specify what is required in your comments to the authors.  
 
No 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions  drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
No 
 
Are you able to assess any statistics in the manuscript or would you recommend an 
additional statistical review?  
If an additional statistical review is recommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
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 o r lose financially from the publication of this 
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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 
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5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
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below. If your r eply is yes to any, please give details below.  
 
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