This document discusses how to critically appraise a research article. It provides 10 questions to ask when appraising an article, including whether the study question is relevant, if the study design was appropriate, and if the data supports the conclusions. As an example, it summarizes a study that examined the relationship between serum cholesterol levels and exposure to violence in suicide attempters. The study addressed relevant questions, utilized an appropriate cohort study design, and its conclusions were reasonably supported by the collected data.

1. Critical
Appraisal
Presented by
How to critically MOHAMED TAHA appraise MOHAMED
an
Assistant lecturer of psychiatry
article?
Faculty of Medicine - Beni Suef University

2. WHAT IS CRITICAL
APPRAISAL??
▪ Critical appraisal is a systematic process used to
identify the strengths and weaknesses of a research
article in order to assess the usefulness and validity of
research findings.
▪ The most important components of a critical appraisal
are an evaluation of the appropriateness of the study
design for the research question and a careful
assessment of the key methodological features of this
design.

3. ▪ Selection and critical appraisal of
research literature
▪ 10 QUESTIONS TO ASK WHEN
CRITICALLY APPRAISING A
RESEARCH ARTICLE:
1-Is the study question relevant?
2-Does the study add anything new?
3-What type of research question is
being asked?
4-Was the study design appropriate
for the research question?

4. TEN QUESTIONS TO ASK WHEN
CRITICALLY APPRAISING A
RESEARCH ARTICLE: Cont.
5. Did the study methods address the most important sources of
bias?
6. Was the study performed according to the original protocol?
7. Does the study test a stated hypothesis?
8. Were the statistical analyses performed correctly?
9. Do the data justify the conclusions?
10. Are there any conflicts of interest?

6. 1- Is the study question relevant?
▪ Even if a study is of the highest
methodological design… it is of little value
unless it addresses an important topic and
adds to what is already known about It.
▪ This is based on subjective opinion, as what
might be crucial to some will be irrelevant to
others.

7. 1- Is the study question relevant? Cont.
In this study:
The question was to determine The role of serum
cholesterol in the cycle of violence.
And to investigate association between
exposure to violence during childhood And
used adult violence in suicide attempters with
low and high serum cholesterol levels.
Which is considered relevant and crucial to
our field of work.

8. 2-Does the study add
anything new?
▪ Research papers that make a substantial
new contribution to knowledge are a
relative rarity.
▪ For example, a study might increase
confidence in the validity of previous
research by replicating its findings.
Or might enhance the ability to
generalize a study by extending the
original research findings to a new
population of patients.

9. 2-Does the study add anything new?
This study discussed a new subject ,role of serum
cholesterol in the cycle of violence . As was found that a
significant correlation between exposure to violence as a child and
expression of violence as an adult(i.e. cycle of violence),only in the
group with cholesterol levels below the median. Serum cholesterol may
thus modify the effect of the “cycle of violence” and might be of interest
as a biomarker concerning risk of expression of violence in traumatised
Individuals
& increased the confidence in the validity of previous
research by replicating its findings e.g. The link between
cholesterol and violence is hypothesised to be Mainly mediated through
alteration of serotonergic activity. Low Cholesterol is related to low
serotonin and, in turn, linked to violence, suicidal behaviour and
impulsivity ( Wallnerand Machatschke, 2009).

10. 3-What type of research question is being
asked?
▪ The most fundamental task of critical
appraisal is to identify the specific
research question; which will determine
the optimal study design.

11. 3-What type of research question is
being asked? Cont.
▪ A well-developed research question
usually identifies three
components:
1-The group of patients.
2-The studied parameter (e.g. a therapy,
clinical intervention, or a risk factor).
3-The outcomes of interest.

12. 3-What type of research
question is being asked? Cont.
In this study the research question identified the three
important components:
1-The group of patients: 81 patients with a recent suicide
attempt .
2-The studied parameter : Serum cholesterol level, the
exposure to and expression of interpersonal violence as a
child and as an adult .
3-The outcomes of interest: Serum cholesterol may thus modify the
effect of the “cycle of violence” and might be of interest as a biomarker
concerning risk of expression of violence in traumatised Individuals.

13. 4-Was the study
design appropriate
for the research
question?

14. -Studies that answer
questions about
effectiveness have a well-established
hierarchy of
study designs based on the
degree to which the design
protects against bias.
- RCTsprovide the
strongest evidence
followed by non RCT,
cohort studies,
case–control studies &
other observational study
designs .

15. 4-Was the study design appropriate for the
research question? Cont.
In this study :
▪ This study design is
considered appropriate for
the research question.

16. 4-Was the study design appropriate for the
research question? Cont.
Cohort, or longitudinal, studies involve following up two or
more groups of patients to observe who develops the
outcome of interest. Prospective cohort studies have been
likened to natural experiments, as outcomes are measured
in large groups of individuals over extended periods of time
in the real world. Cohort studies can also be performed
retrospectively; such studies usually involve identifying a
group of patients and following up their progress by
examining records that have been collected routinely or for
another purpose, such as medical data, death registry
records and hospital admission databases.

18. Advantages of cohort
studies
▪ The temporal dimension, where by
exposure is seen to occur before outcome,
gives some indication of causality
▪ Can be used to study more than one
outcome
▪ Good for the study of rare exposures
▪ Can measure the change in exposure and
outcome over time
▪ Incidence of outcome can be measured

19. Disadvantages of cohort
studies
▪ Costly (less so for retrospective) and may take a long
time, particularly where onset of the outcome measure
can occur both early and late on in life
▪ Require accurate records for retrospective studies
▪ When studying rare outcomes, a very large sample size
is required
▪ Prone to dropout
▪ Changes in aetiology of disease over time may be hard
to disentangle from changes observed as age increases
▪ Selection bias: a difference in incidence of the outcome
of interest, between those who participated and those
who did not, would give biased results

20. 5. Did the study methods address
the most important potential
sources of bias?
In epidemiological terms:
▪ The presence of bias does not imply a preconception
on the part of the researcher, but rather means that
the results of a study have deviated from the truth.
▪ Bias can be attributed to chance (e.g. a random error)
or to the study methods (systematic bias).
▪ Random error does not influence the results but it
will affect the precision of the study.

21. 5. Did the study methods address the most
important potential sources of bias? cont.
▪ Key methodological points to
consider in the appraisal of a
Cohort, study .
 Is the study prospective or
retrospective?
 Is the cohort representative of a
defined group or population?

22. Key methodological points to consider in the appraisal
of a cross-sectional study. Cont.
▪ Were there important losses to follow-up?
 Were all important confounding
factors identified?

23. 5. Did the study methods address the most
important potential sources of bias? Cont.
 In this study
1- Is the study prospective or retrospective?
the study is retrospective .
2-Is the cohort representative of a defined group or
population?
Yes, study participants (81 patients )were
recruited among patients having recently com-mitted
a suicide attempt and having their
clinical follow-up at the Karolinska University
Hospital..

24. 5. Did the study methods address the most
important potential sources of bias? Cont.
3-Were all important confounding factors identified?
Not really;
Because of a small sample size ,leading to a limitation of
the amount of independent variables that could be used
and Relatively large age span might also some what
confound the results.
4-Were there important losses to follow-up?
there are no important losses to follow up.

25. 6. Was the study performed
according to the original protocol?
▪ One of the most common problems
encountered in clinical research is the
failure to recruit the planned number of
participants written in the protocol.
▪ Other differences to the protocol
include:
-changes to the inclusion and exclusion
criteria,
- or variations in the provided interventions
etc...

26. 6. Was the study performed according to
the original protocol?
▪ In this study:
The study protocols (Dnr 93-211) were
Approved by the Regional Ethical Review
Board in Stockholm, and all patients gave
their written informed consent before
inclusion in the study.

27. 7. Does the study test a stated hypothesis?
▪ A hypothesis is a clear statement of what the investigators
expect the study to find and is central to any research as it
states the research question in a form that can be tested and
refuted.
▪ In this study
There was a clear hypothesis stated.

28. 8. Were the statistical analyses
performed correctly?
▪ Assessing the appropriateness of statistical analyses can
be difficult for non-statisticians.
▪ Yet, research articles should include a segment within
their 'Method' section that explains the tools used in the
statistical analysis and the rationale for this approach.
▪ In this study:
▪ Group differences were computed with one-way ANOVA .
 Tests of parametric correlations were performed using
Pearson0`s and non-parametric correlations using
Spearman`s.

29. 9. Do the data justify the conclusions?
▪ The next consideration is whether the conclusions presented
are reasonable on the basis of the accumulated data.
▪ Sometimes an overemphasis is placed on statistically
significant findings that invoke differences that are too small
to be of clinical value;
▪ Alternatively, some researchers might dismiss important
differences between groups that are not statistically
significant, often because sample sizes were small.

30. 9. Do the data justify
the conclusions?
▪ In this study
▪ The conclusions that the authors presented were
reasonable on the basis of the accumulated data:
▪ There is a significant correlation between expo-sure to
violence as a child and expression of violence as an adult(i.e.
cycle of violence),only in the group with cholesterol levels
below the median.
 Serum cholesterol may thus modify the effect of the “cycle
of violence” and might be of interest as a biomarker
concerning risk of expression of violence in traumatised
individuals.

31. 10. Are there any
conflicts of interest?
▪ Conflicts of interest occur when personal
factors have the potential to influence
professional roles .
▪ In the process of critically appraising a
research article, one important step is to
check for a declaration about the source
of funding for the study.

32. 10. Are there any conflicts of interest?
▪ A main mechanism for
dealing with potential
conflicts of interest is open
disclosure.
 In this study:
There was no declaration
about the source of
funding.