Critical Appraisal of the Impact of Yoga on Depression and Anxiety in Women

This critical appraisal evaluates the impact of yoga on depression and anxiety in women. The study used a case-control design and personal information questionnaire, Beck Depression Inventory, and State-Trait Anxiety Inventory test for evaluation. The result suggested that yoga reduces anxiety and depression in women. However, the study has limitations such as population bias and confounding factors. Recommendations are provided to improve internal and external validity.

Running head: CRITICAL APPRAISAL
Name of the student:
Name of the university:
Author note

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CRITICAL APPRAISAL
Question 1:
The study aims to evaluate the impact of yoga on female experiencing anxiety and
depression. Javnbakht, Kenari and Ghasemi (2009), focused on the effect of yoga on the
depression and anxiety of women since Yoga has been considered as an effective stress
management tool which can assist in the reduction of depression as well as anxiety disorders.
Question2:
The author used the case-control study to study the impact of yoga on the depression and
anxiety where twice a week, for 90 minutes 34 participants receive yoga and the control group
received an intervention (Javnbakht, Kenari & Ghasemi, 2009). Ioannidis et al. (2015), suggested
that case-control study is the most suitable study design for evaluating the relationship between
the exposed group and outcome.
Question 3:
The researchers randomly divided into an experimental and a control group, indicating
no selection bias are present in the study. The study only included the patients with the anxiety
and depression and excluded the patients with a history of psychiatric disorders and experience
of yoga (Javnbakht, Kenari & Ghasemi, 2009). The time frame of the study includes July 2006 to
July 2007. The sample size was not adequate since more participants can be recruited by
considering the duration of the study (Lewis, 2015).

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Question 4:
The control participants are also randomly selected to evaluate the impact of the
intervention by comparing exposed and unexposed group (Javnbakht, Kenari & Ghasemi, 2009).
The sample included new patient referrals who willing to take part in yoga without any history
of mental illness. Experimental as well as control groups were matched for demographic details
and both groups were exhibited similar scores in the depression as well as anxiety (Baumberg,
2016).
Question 5:
For minimizing the potential bias, all new cases were evaluated using a personal
information questionnaire, Spielberger (State-Trait Anxiety Inventory) test and Beck depression
inventory objective measurement. The exposure was clearly defined and the measurement
method was similar for case and control.
Question 6 (a):
Apart from the experimental group, the other group such as control group was treated
equally since all the new cases were assessed with proper intervention tools followed by
categorized into the experimental group and control group. Hence, no bias was observed in this
case.
Question 6(b):
The researchers considered confounding factors such as the history of psychiatric
disorders, experience of yoga but excluded while diving the experimental group and control
group. However, the researchers did not mention the economic factors which can influence the

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intervention. Kyriacou and Lewis (2016), highlighted that economic factor can trigger
depression, anxiety and it influences the impact of yoga on the exposed group. Moreover,
another cofounding factor, in this case, is the participation in the new communal group which
further impact the intervention.
Question 7:
The result of the study suggested that yoga reduces strait and trait anxiety. It is also
effective in the reduction of obsessive-compulsive disorder. Yoga encourages individuals to
increase awareness of body tension and potential management of it. It improves autonomic
activity. While it is effective in reducing the depression, depression may require therapeutic
period (Javnbakht, Kenari & Ghasemi, 2009). However, while no direct treatment effect was
mentioned, the authors highlighted that depression was present in 44% of the cases before
intervention which reduced to 32% after the intervention (Javnbakht, Kenari & Ghasemi, 2009).
This result indicated that the treatment effect can be 12% on the intervention group. The
researchers also mentioned that this result is not statistically significant. In case of the anxiety,
pretreatment score was 41% which dropped to 20.6% of cases, signified a statistically significant
data where treatment effect can be 21% (Javnbakht, Kenari & Ghasemi, 2009). The study also
indicated that the score of anxiety and depression was similar at the beginning of the study and
changes observed after the intervention.
Question 8:
Considering the p value of the study, it can be said that the treatment effect of the patient
of anxiety is precious compared to depression. In case of anxiety, after the intervention, the p-
value is 0.03, indicating effective intervention. Considering state anxiety, the treatment effect is

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excellent where the p-value is 0.001. Hence, in case of anxiety, it is effective in terms of
improving self-control of the study whereas depression may require a greater therapeutic period
since no significant difference was observed (Polit, 2017).
Question 9:
The result is reliable since yoga has an important therapeutic role in addition but not a
replacement of the medication. While the result of the study was effective, the study is effective
for the reduction of depression and anxiety in women (Javnbakht, Kenari & Ghasemi, 2009).
This result further highlighted the presence of population bias. Hence, this can further impact the
validity of the study.
Question 10:
Due to population bias present in the study, the study is inappropriate to apply on the
gender neutral local population which is a potential limitation of the study (Claydon, 2015). To
implement it on the local population, the effect of yoga on the other population is required to
consider.
Question 11:
The result of the study can be fit with evidence since significance number of researchers
conducted an observational study in order to evaluate the impact of yoga on the depression and
anxiety and it can be used in the clinical setting as an additional intervention with medication.

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Summary of the measurement of the study:
The researchers used a personal questionnaire for gathering demographic information’s.
For evaluating the depression, researchers used the Beck Depression Inventory and for
evaluating the anxiety, researchers used the state-trait anxiety inventory test. () personal
information questionnaire is the most practice, suitable and inexpensive way of gathering the
demographic data and hence it is the appropriate measurement (Choi, Lee & Sohn, 2017).
Considering the Beck Depression Inventory, Bringmann et al. (2015), suggested that it is
considered as reliable questionnaire for determining depression in normal populations along with
measuring the intensity. It also detects symptoms from the previous week and rates it
accordingly, highlighting its appropriateness. Hence, this measurement scale improves the
internal validity of the study.
Considering
the State-Trait anxiety inventory (Spielberger questionnaire), it is also most suitable method for
assessment symptoms of anxiety. It has 20 pieces for state anxiety and 20 eliment for trait
anxiety (Renner et al., 2018). The advantage of the measurement scale is used to discriminate
whether a patient is experiencing anxiety or depression.
All participants including interventions and controls were used considering these measurements
and in each case, both groups were equally treated. Leung (2015), suggested that manipulation of
measurement parameters where the response of both the group differs impact the internal validity
of the study. In this case, since all groups were treated using the same measurement tools, it
improved internal validity. Hence, the result of the study is reliable for implementing it in the
research.

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Potential threats to the internal and external validity of the research:
Considering the internal validity of the study, the study used randomization to select the
participants, indicating a reduction of the selection bias. Since selection bias is absent, it
improves the validity of the study (Leung, 2015). However, population bias impacted the internal
validity of the study. In the study, the interventions were solely given to the women in order to
improve depression and anxiety, the impact of the intervention on men was considered,
indicating population bias (Javnbakht, Kenari & Ghasemi, 2009). Hence, population bias further
impacted the internal validity of the study because the yoga may or may not have an excellent
impact on men. The research has two confounding factors such as economic factors and
participation in a new communal group which further threat internal validity of the research since
economic factors trigger depression and anxiety and communal participation improve the impact
of yoga (Heale & Twycross, 2015). However, while randomization is present, no blinding was
mentioned in the research which further impacted the internal validity of the study as the result
can be different from blinding.
Considering the external validity of the study, the researchers conducted a case-control
study which is the most suitable research design for evaluating the relationship between the
outcome and exposed group. The researchers also used exclusion and inclusion criteria for
selecting the participants which improve the external validity of the study (Leung, 2015).
However, the sample sizes could be longer which impacted external validity since small size can
reduce the reliability of the research (Leung, 2015). The communal group participation and
gender are sample features which further impact the generalizability of the study.

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Recommendation for avoiding internal and external validity:
For avoiding population bias which impacted the internal validity, the experiment should
be conducted by recruiting the general population or male population in order to evaluate the
impact of the intervention on the population (Javnbakht, Kenari & Ghasemi, 2009). For avoiding
confounding factors, economic factor and participation on the communal group are required to
consider while giving the intervention. It will improve the internal validity of the study.
Moreover, for improving internal validity, the blinding should be introduced so that no personal
factor can influence the impact of the intervention (Leung, 2015).
Considering the external validity of the study, the sample size should be increased for gathering
the adequate response of the intervention. External validity also can be improved by
incorporating other characteristics of the population for evaluating the effectiveness of yoga. For
impacting external validity, the period of the study could be improved so that the response for
depression can be evaluated (Leung, 2015).
References:
Baumberg, B. (2016). The stigma of claiming benefits: a quantitative study. Journal of Social
Policy, 45(2), 181-199.
Bringmann, L. F., Lemmens, L. H. J. M., Huibers, M. J. H., Borsboom, D., & Tuerlinckx, F.
(2015). Revealing the dynamic network structure of the Beck Depression Inventory-
II. Psychological medicine, 45(4), 747-757.

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Choi, H. S., Lee, W. S., & Sohn, S. Y. (2017). Analyzing research trends in personal
information privacy using topic modeling. Computers & Security, 67, 244-253.
Claydon, L. S. (2015). Rigour in quantitative research. Nursing Standard (2014+), 29(47), 43.
Heale, R., & Twycross, A. (2015). Validity and reliability in quantitative studies. Evidence-
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Javnbakht, M., Kenari, R. H., & Ghasemi, M. (2009). Effects of yoga on depression and anxiety
of women. Complementary therapies in clinical practice, 15(2), 102-104.
Kyriacou, D. N., & Lewis, R. J. (2016). Confounding by indication in clinical
research. Jama, 316(17), 1818-1819.
Leung, L. (2015). Validity, reliability, and generalizability in qualitative research. Journal of
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Lewis, S. (2015). Qualitative inquiry and research design: Choosing among five
approaches. Health promotion practice, 16(4), 473-475.
Polit, D. F. (2017). Clinical significance in nursing research: A discussion and descriptive
analysis. International journal of nursing studies, 73, 17-23.
Renner, K. H., Hock, M., Bergner-Köther, R., & Laux, L. (2018). Differentiating anxiety and
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