Title: Child marriage and risky health behaviors: An analysis of tobacco use among early adult
and early middle-aged women in India
Version: 2 Date: 04 Jan 2022
Reviewer's report:
This is a strong manuscript linking child marriage with tobacco use among women in India.
It uses nationally representative data (NFHS) from India to show that child marriage increases
the odds of tobacco use among women in India. Furthermore, the authors show that the odds
of tobacco consumption increase proportionately with decreased age at marriage – “the lower
the marital age, the higher the risk of tobacco use (pg. 7)”. The literature review is relevant, the
methods are appropriate, the findings are novel, and the manuscript is well developed and easy
to read. The results section is also clear and the discussion meaningful. I particularly enjoyed
reading the analogy between child marriages and ACEs and the increased risk, therefore, of
risky health behaviour following child marriages. However, the manuscript needs to be revised
before it can be considered for publication.
Abstract: The results present unadjusted odds ratios, and they appear to be misleading as the
adjusted odds ratios (OR) are lower in magnitude. Furthermore, these results exaggerate the
difference between the two age categories – early adulthood and early middle-aged. The ORs for
child marriage across the two age categories are quite similar in magnitude in the adjusted model.
I have also not seen unadjusted ORs being presented as the primary result in the abstract. My
recommendation is that the authors present adjusted ORs or mention that they present unadjusted
ORs. Given systematic differences across the two population groups (child marriage and adult
marriage), adjusted ORs are more appropriate when discussing the association of child marriage
with the outcome.
Literature review: The review is appropriate but misses a critical recently published study
(Vikram 2021). It uses the life course framework and a similar age categorization to find that
child marriage increases the odds of functional limitations and chronic diseases among women
in India in middle age. It also links child marriage with poor self-rated health in youth and middle
age.
Vikram, K. (2021). Early marriage and health among women at midlife: Evidence from India.
Journal of Marriage and Family, 83(5), 1480-1501.
Methods: The sample selection for the study is confusing. The NFHS data include women from
ages 15-49 years. It is not apparent why the authors limited the sample to women aged 22-44. A
justification needs to be provided for this restriction. The primary analyses need to be performed
(and shown in the appendix) on the entire sample as a robustness check.
Additionally, the authors limit the sample to women who were married before the age of 21.
They state this is done because “con#ning marriage age prior to age 22 ensures uniformity of the
study sample; and second, those who were married during youth or late adolescence (between
age 18 to 21 years) were more comparable to those who were married as a child (before age
18 years).”
These sentences need more explanation as the current description is inadequate in conveying
the reasoning for these decisions. How does con#ning marriage age prior to age 22 ensures
uniformity of the study sample? How are women married as children more comparable to women
married during youth or late adolescence? These statements need to be backed up by evidence.
In the same paragraph, the authors state that this marital age restriction does not impact their
results, but they do not show the other results. Those results (without these restrictions) need
to be included in the appendix.
It is not apparent why the authors split the sample into two age categories - early adult and
early middle-age. Given that the odds of tobacco consumption are not remarkably different in
magnitude across the two groups after adjusting for controls, it is not clear what the advantages
are from such a division. A theoretical explanation needs to be provided for this division.
Lastly, another figure should accompany Fig. 2 showing the adjusted margins as these would
present a somewhat different picture of the differences across the two groups. The differences
across the two age groups would be significantly reduced.
The state analyses are unimportant and should be relegated to the appendix.