Assignment about What is Cohort?

Part A
Table 1 Cohort Study (Mulugeta, Zhou, Power, & Hyppönen, 2018)
Paper for appraisal and reference: Mulugeta, A., Zhou, A., Power, C., & Hyppönen, E. (2018).
Obesity and depressive symptoms in mid-life: a population-based cohort study. BMC
Psychiatry, 18.
Appraisal
question
Yes No Can’t tell
1. Did the study
address a clearly
focused issue?
The study presents a
focused issue as the title
mentions the population,
intervention. It also
mentions the type of study
that is cohort study, which
helps in search through the
database.
2. Was the cohort
recruited in an
acceptable way?
The data was used
from 1958 British
birth cohort, so, the
recruitment of the
cohort was not done
in an appropriate
manner as it was
done for the purpose
of the study to be
undertaken.
3. Was the
exposure
accurately
measured to
Clinical Interview
Schedule-Revised (CIS-R)
and Mental Health
Inventory − 5 (MHI-5) were

minimise bias? used to investigate the
depressive symptoms. Both
of which have justifiable
validity.
4. Was the outcome
accurately
measured to
minimise bias?
Weight, height and waist
circumference (WC) were
measured by skilled nurses
via Tanita solar scales,
stadiometer and body
tension tape, waist
circumference respectively.
BMI was calculated.
5. (a) Have the
authors
identified all
important
confounding
factors?
Authors took into account
risk sociodemographic and
lifestyle factors and
existence of symptoms of
depression at baseline.
(b) Have they
taken account of
the confounding
factors in the
design and/or
analysis?
Yes confounding factors
such as sex, region, and
social class and various
lifestyle factors were taken
into account.
7. (a) Was the
follow up of
subjects
complete
enough?
Yes
(b) Was the
follow up of
Yes, it followed up for 5
years.

subjects long
enough?
9. What are the
results of this
study?
At 45 years, nearly 25% and
35% respondents were
categorized as having
general obesity and central
obesity, respectively.
Incidence of depression
8.4% at 45 years and 12.4%
at 50 years.
Sociodemographic and
certain lifestyle aspects that
were related to increased
incidence of general and
central obesity were also
related to increased
incidence of depressive
symptoms.
10. How precise are
the results?
Results were precise as per
the CI ranges.
11. Do you believe
the results?
Results are believable as the
support the findings of
previous studies.
12. Can the results
be applied to the
local population?
No, because,
representativeness is
a limitation of the
study as the
demographic
structure of the
current UK
population has more

diversity than
included in this
study. So, the
results may not be
generalizable.
13. Do the results of
this study fit
with other
available
evidence?
Yes, it did correspond with
previous researches.
14. What are the
implications of
this study for
practice?
The study implicates that
while managing depression,
obesity and other lifestyle
factors could be one of the
management approaches.
Table 2 Case control study (Koski & Naukkarinen, 2017)
Paper for appraisal and reference: Koski, H. M., & Naukkarinen, H. (2017). The Relationship
between Depression and Severe Obesity: A Case-Control Study. Open Journal of
Psychiatry, 7(4), 276-293. doi:10.4236/ojpsych.2017.74024
Appraisal question Yes No Can’t tell
1. Did the study address a
clearly focused issue?
The population
included in the
study is retired
individual which
is not mentioned
in the title of the
study.

2. Did the authors use an
appropriate method to
answer their question?
Yes
3. Were the cases recruited
in an acceptable way?
Cases were based
on people who
were getting a
disability pension
because of
obesity.
4. Were the controls
selected in an acceptable
way?
The controls were
chosen by random
sampling and
matched with
cases as per the
residence and sex.
5. Was the exposure
accurately measured to
minimise bias?
A personal
psychiatric
interview and the
Beck Depression
Inventory were
used to measure
the prevalence of
depression.
6. (a) Aside from the
experimental
intervention, were the
groups treated equally?
There is no
mention of non-
experimental
treatment.
(b) Have the authors
taken account of the
potential confounding
factors in the design
The study group
was effectively
matched with the
control group with

and/or in their analysis? matching
occupational and
social statuses.
The impact of the
cases’ life
situation was
minimized as
individuals in the
control group had
also been getting a
pension for the
similar duration.
7. How large was the
treatment effect?
Subject group
demonstrated
increased
diagnosis of
depression as
compared to
control group as
per the psychiatric
interview. On the
basis of
conditional
logistic linear
model, people
having severe
obesity had
increased
likelihood of
depression as
compared to the