Research Methodologies in Epidemiology Assignment

Running head: EPIDEMIOLOGY 1
RESEARCH METHODOLOGIES IN EPIDEMIOLOGY
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EPIDEMIOLOGY 2
Question one
a) ``What study design does this study employ``? [1point]
 The study uses a cohort study design. A cohort study depicts a clinical research
study in which individuals who currently have a particular condition or illness or get
a given treatment are followed over time. Normally, different study designs give
information of varied quality (Mark, 2013). This evidently implies that the choice
of the study design by any given researcher influences the quality of the information
generated in the particular study. As such, it is indispensable for any researcher to
be prudent when identifying the most appropriate study design to adequately
address all the necessary study elements.
b) ``Find the methodological aspects mentioned in the paper that convinced you
that is the type of study design, please use dot points`` [2points]
 The data collection aspect. In the research paper, the data involving the national
random sample of 2,645 men and 2,551 women aged between 35 and 74 were
gathered in the years 1988 and 1989 respectively, after which they were perpetually
monitored concerning incident cases of CHD until December 31, 2000. As such,
the duration for data collection was continuous although it was done on the original
sample size.
 The data analysis aspect. As vividly evident in the research paper, the data
collected in the study was analyzed after the completion of the follow-up on the
initial random sample subjects. This implies that the records from the responses to
the interview and questionnaires questions and the follow-up observations on the
study subjects were conclusively analyzed at the end of the study period on
December 31, 2000.
c) ``What justification do the authors give for conducting this study, please use dot
points`` [2points]
 To adequately address the gap of the absence of holistic inclusivity of study subjects
from varied socioeconomic status in the sample in the previous researches. They
argue that in the previous research studies, there has been an overt lack of a
wholesome inclusivity when selecting the study sample. For instance, the authors
argue that a majority of the previous researches on the association between physical
inactivity and CHD have failed to include individuals with low socioeconomic status
(SES). As such, they are seeking to bridge this particular gap by including individuals
from the low socioeconomic status as well as those from other socioeconomic
statuses.
 The need to include both genders, that is, both men and women in the study to counter
the lack of such inclusivity by the previous researchers. According to them, such an
inclusivity of the two genders would produce more reflective and reliable conclusions
in the study. For example, they point out the relative neglect of women in the studies
of CHD epidemiology. Evidently, including both men and women in their study is a
chief reason for motivating them to conduct this particular study.

EPIDEMIOLOGY 3
d) ``What was the proportion of those who (i) do not do any physical activity (ii)
engaged in twice a week vigorous physical activity``? (You are not required to
report 95% confidence intervals) [2points]
 The proportion of the individuals who do not perform any physical activity at all
according to the results table is 9.0%, which represents a sample size of 463 out of the
total sample size of 5191.
 Based on the results table in the research, the proportion of those who took part in
twice a week vigorous physical activity was 10.9%, which reflects a sample size of
563 out of the overall sample size of 5191.
e) ``What is the crude incidence rate of CHD in inactive men and inactive
women``? [2points]
 In this case, the crude incidence rate describes the number of new coronary heart
diseases in both the inactive men and women during a given period, expressed as the
number such cases per 10,000 population at risk. As such, the crude incident rate of
CHD in physically inactive men is 111.
 For the case of women, the crude incident rate is 38.
f) ``What is the crude relative risk of being non-active versus being ``highly
active``(`vigorous physical activity at least twice a week) in men and` women``
[2points]
 For men, it is 111:61
 For women, it is 38:14
g) ``How would you interpret the relative risk in the above section f?`` [2points]
 The relative risk in both the genders exhibits a similar trend. That is, the crude risk is
high for men and women who do not perform any active physical activity at all while,
on the other hand, those who engage in vigorous physical activity twice or more than
twice a week have a lower crude risk. This means that the highly physically active a
person is the higher the possibilities of not suffering from CHD conditions. Similarly,
the opposite is vividly true. Based on this observation, it is therefore advisable for
individuals to engage in physically active and if possible vigorous physical activities
two or more times in a week. This will lower the chances of them having such life-
threatening CHD conditions. This should be encouraged across the board, that is, in
both men and women of all ages.
h) ‘Looking at the sex and age-adjusted RR in Table 3 (the RR is measured by the
Hazard Ratio which is similar) (i) how would you describe the association
between physical activity and CHD” [4 points]
 Men and women who were completely physically inactive have increased chances of
suffering from CHD. This is expressed in the HR=1 as shown in the table. This
implies that such people face a highly possible likelihood of contracting CHD
conditions and this is attributed to the absence of physical activities in their lives.
This illustration should quite serve as a warning to those people who are reluctant or
lazy about performing some active physical activities in their lives. They should see
it as an opportunity to avert such possible chances of getting CHD. Evidently, they
can achieve this by starting with simple regular physical exercises at their home or
work places if possible.