Introduction to Epidemiology

Introduction to Epidemiology

Question 1: [26]
Read the following paper, and answer the questions below: “Vo TM, Tran VTN, Cuu
TNT, Do TTH, Le TM. Domestic violence and its association with pre-term or low
birthweight delivery in Vietnam. International Journal of Women Health 2019:11
501–510”
(a) “What study design does this study employ and identify from the paper
methodological features that support the design you just noted ?” [2 mark]
A: This study employs cross-sectional study design through conducting interviews
among women aged 18-49 years in Vietnam, experienced Domestic Violence, and
having a child less than 2 years. The methodology was followed through selecting
sample size using sampsi command through STRATA, performing data-collection
through WHO generated questionnaire, measuring variables, conducting the study
process and analysing data.
(b) “What is/are the main exposure/s and what is/are the main outcome/s of this study
in operational terms (i.e., you answer should include how the measure was defined)?”
[4 marks]
A: The study was conducted to understand implication of domestic violence on
pregnant women, on pre-term babies, and low birth-weight deliveries. The study
findings were collected through cross-sectional study designs from 1,099 women who
had experienced domestic violence during or before pregnancy. The measurement
data was based on three variables, ore-term babies, low birth-weight, physical,
emotional, sexual violence. The main outcome from the study showed that domestic
violence through emotional, physical and sexual violence raised chances of delivering
pre-term and low-birth-weight babies by 1.44 times, than normal circumstances.
(c) “Do you think the risk of selection bias is high or low? Your answer should be
justified by no more than 60 words!! Too long answer will be penalised ?” [4 marks]
A: There is low selection bias risk as the sample collected is randomly selected
through 10 districts, from initial 24 districts. After alphabetical ordering of 132
communes, systematic random sampling was used to create 32 communes from these

132, through a selection interval of 4. 37 women were randomly selected to improve
sampling size and 80% chances through significance level of 0.05.
(d) “Compute the crude OR for domestic violence (yes/no) and pre-term/low
birthweight from data presented in Table 4 and interpret this in your own words.” [4
mark]
A: Yes, the crude odd ratio for pregnant women suffering from Domestic Violence
and giving pre-mature or low birth-weight babies is 1.44. The most important reason,
which attributed to the effects of pregnancy because of domestic violence, is based on
sexual violence with crude OR 1.5. Moreover, the other two reasons physical and
emotional violence during domestic violence has no major association on the birth
results of babies. Depending on occupation, housing status, economic status,
husband’s age, and husband’s addiction to alcohol, the study found families with less
economic security had high risk of giving pre-term babies. Moreover, women having
husbands addicted to alcohol has OR 1.87, which significantly affects the delivery of
pre-term and low eight babies.
(e) “Was the crude OR differ from the adjusted and if yes why? if no why?” [4
marks]
A: Yes, the crude OR is different from the adjusted prevalence odd ratios in the
measurement of domestic violence impact on pre-term babies and low-birth-weight
babies. In addition, emotional violence physical violence and sexual violence also
leads to the debilitating effects of pregnancy outcomes, which can be seen from the
varied OR and POR. The OR for domestic violence effect in pregnancy outcomes is
1.44, with P-value of 0.029. For emotional violence OR is 1.27 against 1 and P-value
0.250. For physical violence OR is 0.69 against 1, and P-Value 0.237. Lastly, for
Sexual violence OR is 1.49 against 1 and P-value is 0.046. Throughout the study
sexual violence was the most significant cause, leading to negative pregnancy
outcomes.
(f) “What was the prevalence of physical violence in this sample and what was the
adjusted prevalence odds ratio (POR-Table 5) between physical violence and pre
term/low birthweight? Interpret the association in your own words, could it be a result
of some error?” [4 marks, no more than 100 words]