Critical Appraisal of Obesity and Depression Studies in PUBH6005

This report critically appraises three studies investigating the relationship between obesity and depression. The first study is a cross-sectional study examining the association between obesity and depression, the second is a cohort study looking at the impact of socioeconomic status on the relationship between obesity and antenatal depression, and the third utilizes a randomized controlled trial to explore the association of diabetes and depression. Each study is evaluated for its research question, methodology, strengths, and limitations, including sample size, study design, and potential biases. The report analyzes the findings of each study and assesses their relevance, reliability, and validity in the context of public health. The report uses a structured approach to critically evaluate the studies, considering factors such as study design, sample selection, measurement validity, statistical significance, and the potential for confounding factors. The findings from each study are summarized, and their implications are discussed. The report aims to provide a comprehensive overview of the current state of research on the relationship between obesity and depression, and to highlight areas for future research.

Running head: OBESITY AND DEPRESSION
Obesity and Depression
Name of the Student
Name of the University
Author Note

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OBESITY AND DEPRESSION
Critical appraisal refers to the systematic process of analysing any article to examine
its relevance, reliability and validity. In addition to this, critical appraisal will allow to find
out the strengths and limitations of articles ( Marcus, 2014). There are different type of
checklists for analysing different types of study.
Obesity is one of the major contributor global disease burden and this trend of obesity
is enhancing day by day (Seidell & Halberstadt, 2015). In addition to this, it is also reported
that, due to the increasing issue of obesity, the incidents of depression are also enhancing. In
various studies, the association of obesity and depression is identified in a well manner.
However, in multiple studies, it was reported that, there was a significant relationship among
the obesity and depression (Polanka et al., 2017).
According the study of Jokela et al. (2014) it was reported that, onset of depression is
positively promoted by condition of obesity among the subject population of this study. The
study of Lasserre et al. (2014), also reported that there is a significant positive relationship
among obesity and depression.
Research question
Can obesity promote depression?
Methodology
University databases were used to identify the related studies by using key words like
association of obesity and depression, onset of depression due to obesity, onset of depression
among high BMI population. Among all the identified articles, 3 articles were selected that
includes RCT, Cohort study and Cross-sectional study.
Strengths and Limitations

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OBESITY AND DEPRESSION
The primary strengths of the three chosen study is the large sample size and in three chosen
studies, different techniques are used to identify the relationship. However, in one study, the
authors failed to conclude any significant relationship among obesity and depression.
Statements Answers Comments Justification
Did the study address a
clearly focused question
/ issue?
Yes
The objective is to examine the
relation of obesity and mental health
that is depression and anxiety.
The study tries to
identify the
psychological changes
associated with the
obesity.
Is the research method
(study design)
appropriate for
answering the research
question?
Yes
This study aimed to examine the
output of psychological condition of
the patients who are suffering from
obesity.
Cross-sectional study
design examines
exposure and outcome
related to obesity and
depression.
Is the method of
selection of the subjects
(employees, teams,
divisions, organizations)
clearly described?
Yes The data of the sample population
were collected from the outpatient
obesity clinic and none of the subjects
were suffering from any systematic
illness. In addition to this, the subject
population were not addicted to drugs.
The selection process
is clearly mentioned in
the method section of
this study.
Could the way the
sample was obtained
introduce
(selection)bias?
Can’t
tell
All the patients were selected from an
outpatient clinic with a few exclusion
and inclusion criteria. The selected
sample size had a blood test after
having 12h fasting.
There is no conclusive
evidence or information
regarding the sample
selection process of this
study.
Was the sample of
subjects representative
with regard to the
population to which the
findings will be
referred?
Can’t
tell
The study participants belonged to the
different age group and they were
selected from the clinic without
examining the age group of the people.
There is no conclusive
evidence or information
regarding the
representative nature of
the study population.

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OBESITY AND DEPRESSION
Was the sample size
based on pre-study
considerations of
statistical power?
No This study is not based on any
previous study. The author conducted
this study as it was reported that
depression has become one of the
major problem of world and obesity is
highly correlated with depression. In
addition to this, researchers also found
that, anti-depressant drugs are mostly
prescribed to the patients of obesity.
Authors selected the
sample size randomly.
There was not any
references mentioned
regarding the sample
size of the study.
Was a satisfactory
response rate achieved?
Yes In the study, 253 females and 47 males
were recruited. Among the total
sample size, 249 people have a BMI of
> 30 kg/ m2 and 51 have a BMI of >
25 kg/m2.
All of the patient
collected patient’s data
were analyzed in this
study.
Are the measurements
(questionnaires) likely
to be valid and reliable?
Can’t
tell.
The body weight of the patients were
measured by using a digital meter and
the body height was measured by
using the fixed stadiometer. BMI was
measured and categorized by using the
WHO cut-off points for normal
weight. The waist circumference was
measured by using a flexible tape and
then waist –hip ratio was calculated.
For assessing the depression among
the selected subject population the
Beck depression–anxiety scale was
used and it comprised of 21 self-
reported questionnaires.
There is no conclusive
evidence regarding the
validity of the
collection method. Only
the guideline of WHO
was mentioned and
there was no other
information regarding
this.
Was the statistical
significance assessed?
Yes The BMI , waist circumference and
hip- waist ration is very relevant to the
obesity and on the other hand the use
of anxiety-depression measuring scale
also backed the findings of this study.
Statistical analysis was
executed by using the
SPSS program for
windows v. 17.00 and
the baseline data was
were expressed by

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OBESITY AND DEPRESSION
using the mean ±SD.
An independent sample
t-test was used to
examine the differences
between the groups. In
this study, a p value of
p<0.05 was used to
identify the significance
of the study result.
Are confidence intervals
given for the main
results?
No No, confidence interval was
mentioned for the final study result.
Confidence interval was
not calculated or not
mentioned.
Could there be
confounding factors that
haven’t been accounted
for?
No The mood, symptoms and behavior of
the depressed people were mentioned
and it was quite correlating with the
study.
During the survey all of
the probable data was
collected and correlated
with each other to find
the association.
Can the results be
applied to your
organization?
No All the study population was collected
from only one outpatient clinic and
most of the study population were
female. So, it cannot be used in case of
all people.
It may possible that,
the findings of this
study may differ in case
of male population or in
case of equal number of
male and female
population of this study.
Study 1.Association between obesity and depression-Cross sectional- Altunoğlu et al.
(2015)
Study 2

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OBESITY AND DEPRESSION
Molyneaux, E., Pasupathy, D., Kenny, L. C., McCowan, L. M. E., North, R. A., Dekker,
G. A., ... & SCOPE consortium. (2016). Socio-economic status influences the
relationship between obesity and antenatal depression: data from a prospective cohort
study. Journal of affective disorders, 202, 124-127.
Statement Answer Comment Justification
Did the study address
and clear focus
Yes This study clearly addressed the focused
issue that is association of obesity and
depression is dependent on the
socioeconomic status of individuals as
study result showed that among the higher
socioeconomic status, there was no
significant correlation among obesity and
depression.
It is identified in
the study clearly.
Was the cohort recruited
in an acceptable way
Yes The data were collected from the SCOPE
cohort that recruited healthy nulliparous
women with singleton pregnancies from
the study centers of the UK (London,
Leeds and Manchester), New Zealand
(Auckland), Australia (Adelaide), Ireland
(Cork) in between November 2004 and
January 2011. The pregnant women who
had 14-16 weeks’ gestation period were
recruited to this study and follow up was
taken till the delivery period of patients.
Follow up was
taken in a regular
manner to
compare the
study result.

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OBESITY AND DEPRESSION
Moreover, underweight women, women
with previous fetal loss before (22 weeks),
were not recruited in this cohort
(Molyneaux et al., 2016)
Was the exposure
accurately measured to
minimise bias?
Yes The antenatal depression among the
pregnant women was assessed by using the
Edinburgh Postnatal Depression Scale
(EPD). For standardizing the depression
among the pregnant patients, a score of </
13 on the EPDS was selected as standard
level (Meijer et al., 2014). The body mass
index of the patients were calculated from
the height and weight data of patients and
none of BMI data was missing from the
analysis method.
The
socioeconomic
data of the
patients were
collected from
self reported pre
tax income
database for
measuring the
secondary
outcome.
Was the outcome
accurately measured to
minimise bias?
yes All the subject population’s data were
collected by using same tools and the
depression measuring scale was validated
All the
measurements
were same for all
the subject
population.
Have the authors
identified all important
confounding factors?
Yes In this authors have specified all the
required cofounders such as Body Mass
Insex (BMI) for obesity. For correlating
depression authors have identified the
socio economic status of the subject
population.
Moreover, self
reported co-
founders were
also used in this
study. The used
cofounders were
gestation, marital
status,
employment

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OBESITY AND DEPRESSION
status,
education,
ethnicity and
age, pre-
pregnancy
alcohol
consumption,
pre-pregnancy
smoking and
previous
pregnancy loss.
Was the follow up of
subjects complete
enough?
No No the follow-ups of the subject
population was not enough as the subject
population was followed up till their
delivery and after that no information were
collected.
Follow up was
only taken up to
the delivery of
pregnant woman.
Was the follow up of
subjects long enough
Can’t
tell
The subject population was followed from
the 15-16 weeks of gestation and followed
till their delivery. There was no specific
information regarding the adverse outcome
after the delivery. Authors had not
specified anything about the adverse event
after completion of the follow up period.
None of the
subject
population were
reported to leave
the study before
completion.
Can the results be
applied to the local
population?
Yes The study can be applied locally as this
study, tried to found the correlation
between obesity and depression among the
low and high socioeconomic woman of the
society.
Although, the
study is based on
the pregnant
woman, still the
study covered
almost all kind
of people in the
society. So, it
can be said that,

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OBESITY AND DEPRESSION
this study can be
applied to local
population.
Study 3
Ma, J., Yank, V., Lv, N., Goldhaber-Fiebert, J. D., Lewis, M. A., Kramer, M. K., ... &
Blonstein, A. care: A type 1 hybrid design randomized controlled trial. Contemporary
clinical trials, C. (2015). Research aimed at improving both mood and weight clinical
trials, C. (2015). Research aimed at improving both mood and weight (RAINBOW) in
primary 43, 260-278.
In this study a randomized controlled trial method is used to identify the association of
diabetes and depression.
Statement Answers Comments Justification
Did the trial
address a
clearly focused
issue?
Yes The study of Ma et al. (2019), clearly
focused the issue that they identified
previously. The outcome of the study
showed that, the proposed
intervention was valid and had a
significant relationship with the
problem identified by the
researchers.
The objective is
described in this
study.
Was the
assignment of
patients to
treatments
randomised?
Yes Participants of this study were
included in this study from 30th
September, 2014 to 12th January,
2017 from the 4 medical centers of
Sutter Health’s Palo Alto Medical
The study
coordinators asked
patients to take part in
the study who had
previously diagnosed

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OBESITY AND DEPRESSION
Foundation. All the patients’ data
were recorded at the family and
internal medicine department of
these four hospitals. All the adult
patients were eligible for this study
if they had the BMI of 30 or more,
had depressive symptoms as per the
9-item Patient Health Questionnaire
(PHQ-9) score of 10 or more and
they should not had any co-morbidity
issues
depression. Random
selection process was
followed during the
distribution of patients
to the intervention or
control group. Patients
had no information
regarding this
allocation, however
researchers were not
blind about this
allocation process
( Ma et al., 2015).
Were all of the
patients who
entered the
trial properly
accounted for
at its
conclusion?
yes Among the intervention group
patients, it was reported that 35
patients lost to follow up and among
them 21 patients withdrew
themselves from the study due to
their personal reason and 14 patients
were non-responsive to the study
coordinator. On the hand, from the
usual care group, 30 patients
withdrew themselves from the study
and among them 19 patients
withdrew themselves due to personal
reason
40 patients left the
study due to personal
reason.
Were patients,
health workers
and study
personnel
‘blind’ to
treatment?
No The study coordinators and the health
care professionals were not blind to
the treatment.
However, the patients
were blind to the
treatment and they
only received the
treatment.
Were the
groups similar
No From the data of the study
participants’ it was observed that, the
Moreover, differences
were reported in terms

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OBESITY AND DEPRESSION
at the start of
the trial?
number of male and female
population of this study was not
equal.
of education level,
socio-economic level,
marital status
Aside from the
experimental
intervention,
were the
groups treated
equally?
Can’t tell There were no specific information
regarding the additional treatment
process other than the intervention in
this study ( Ma et al., 2015).
It is not described in
this study.
How large was
the treatment
effect?
Large The primary outcome of this study
suggested that at 12 months, the
patients who were in the intervention
group, had significantly better BMI
and SCL-20 scores while comparing
with the usual care patients. In the
intervention group, mean decline of
BMI reported to 35.9 from 36.7. In
case of the control group no change
was reported. In case of SCL score
the mean decline was reported to
1.from 1.5. In the usual care group,
the mean decline was recorded
almost 1.4 which was not
significantly reduced (Previously
1.5). The secondary outcomes of this
showed that, mean weight was also
declined in intervention group at 12
months of the study intervention.
The mean weight was
declined to 100.8 kg
from 103.4 kg. On the
other hand, the usual
care group, had only
slight decrease in the
mean body weight
from 103.4 kg to
103.2 kg. In terms of
SCL scores, there was
almost 50%
improvement among
the intervention group
patients at 6 months.
However, this
outcome was not
reported for the
control group patients.
Reduction of BMI
was also greater
among the males of
the intervention group
while compared to
usual care groups.
However, this

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OBESITY AND DEPRESSION
outcome was not
reported in case of
female subject
population
How precise
was the
estimate of the
treatment
effect?
Significantly
precise
The p value for this study was
estimated at 0.01 and in all the cases
it was observed that confidence
interval (CI) was calculated as 95%
All the study
findings showed that,
study results had the p
value of 0.01 with
95% CI and that
indicated that there
was significant
correlation in between
the intervention and
control group of the
study
Can the results
be applied to
the local
population, or
in your
context?
Yes Although, this overall study was
conducted with 405 sample
population, this study used various
people of different age, sex, and
ethnicity. So it can be said that, this
study can be applied in the local
context.
Can be used in local
region.
Were all
clinically
important
outcomes
considered?
Yes All the possible clinical outcomes
were addressed properly in this study
as it was reported that rate of
prescription generation for anti-
depression medication was reduced
among the intervention group
patients from 47.3% to 42.0% after
randomization.
All the clinical
outcomes are
addressed by the
researchers.
Are the
benefits worth
the harms and
Can’t tell Authors did not specify anything
regarding harms and costs of this
Any information
regarding this topic is

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costs? study intervention not mentioned.