Title: A cross-sectional study of women’s Autonomy and Modern Contraception Use in Zambia
Version: 2 Date: 20 May 2022
Reviewer's report:
At first, I am extremely sorry for being late. Many thanks to offer me to review this paper.
The authors cover an important area; however, I did not see any new findings that the authors
presented in this paper. Most importantly, I do not think that the authors analysed data properly
as I found several serious errors in reported prevalence and variable making procedures. Among
these the most important issues were:
• I was first surprised to see that the modern contraception prevalence in Zambia is only 8.8% that
the authors reported in this study. However, when I checked with the Zambia Demographic and
Health Survey (ZDHS) report, which data authors analysed in the current study, I found it is 43%
for sexually active unmarried women and 48% for sexually active married women. Since the
authors considered partnered women, it should be both sexually active married and unmarried
women, therefore the true prevalence would be between 43% to 48%. I am not sure why such a
huge variation occurred in the reported prevalence. This is probably because of errors in making
the relevant variable during analysis. If this is true, then all analyses in this paper are WRONG.
• In the ZDHS, contraception use or non-use data were collected from 13683 partnered women.
Therefore, the authors need to analyse this sample. However, the authors analysed data of 6727
women which is not correct. Excluding this higher number of respondents from the analysis
without any good reasons is not justifiable.
•  I am also concerned about one of the inclusion criteria that the authors used: not planning
for pregnancy. It is not mentioned in the manuscript what time the authors considered for this
inclusion criteria. Usually, two-year time is considered.
• The authors created the Women's autonomy variable by adding 12 variables under the three
broad headings: Women's participation in decision making, Women's attitude toward wife-
beating, and Women’s household Status. I have several concerns over this variable making
procedure.
a. It is not a good idea to generate the mean score using simple average for this case. I am talking
as some respondents can have missing data for any variables included in the analysis. If this is the
case then the average would produce a wrong result as the authors need to adjust the denominator
accordingly which is not possible in the current way of analysis. I would recommend authors to
use factor analysis here to generate the autonomy score.
b. I am happy with the 10 variables under the headings Women’s participation in decision
making, Women’s attitude toward wife beating to be included to make the autonomy variable.
However, it is not a good idea to consider whether women have their own house or own land to
be considered in making the autonomy variable. Many women, particularly poor women, do not
have their own land or house, but they still need contraception. Even many rich and educated
women do not have their own house or land. This is very common in developing countries as
well as developed countries.  Therefore, this is not right to add this variable to make women’s
autonomy variable.
c. The ZDHS survey data is hierarchical and clustered, therefore, multivariate analysis is not
the best approach here. The authors need to use the multilevel mixed effect model to analyse
this study data. I would prefer a multilevel mixed-effect Poisson regression model for more
appropriateness.
Please see chapter 7 of the ZDHS report for details. Many thanks!