Systematic Review Report

Running Head: SYSTEMATIC REVIEW REPORT
1
Systematic Review Report
Student’s Name
Institutional Affiliation

SYSTEMATIC REVIEW REPORT 2
Systematic Review Report
Introduction
Research is an orderly review of available data to generate new information, by making
correlations to prove or disprove a scientific claim (Chen, 2016). The research process is
categorized differently based on the data being analyzed and the manner of analysis used.
Subsequently, the findings are used to improve on effectiveness, ease or creativity across various
disciplines such as finance, governance, and medicine. The use of research in medical practice is
known as an evidence-based practice (Balakas & Smith, 2016).
The knowledge obtained from research is assessed before it can be applied. The study
design gives the best indicator for the strength of the evidence obtained. A systematic review of
each study design offers the highest level of evidence within their respective categories while the
penultimate measure of the best source of evidence is a systematic review of randomized clinical
trials (Smith, Devane, Begley, & Clarke, 2011). However, it is not a definitive measure of
evidence.
A systematic review entails using defined criteria to abstract secondary data from
research papers, critically appraise them and generate results. There are numerous types of
systematic reviews such as qualitative, effectiveness, prevalence, cost, and risk reviews. All
these types of reviews assess different phenomena in varied contexts. For example, effectiveness
reviews evaluate the effectiveness of an intervention in comparison to a control group by
assessing experimental, quasi-experimental and observational studies. The purpose of this report
is to critically plan a systematic review after the formulation of a research question.
Background
Obesity is a non-communicable disease characterized by a disordered weight gain and
accumulation of adipose tissue that predisposes one to health complications. The constant
hyperglycemic state causes excessive release of insulin. Insulin receptors in organ tissues such as
the liver become resistant due to continued exposure resulting in type 2 diabetes (Paulus et al.,
2015). Hyperlipidemia also commonly occurs in obese patients resulting in atherosclerosis
causing coronary artery disease. It is hypothesized that excessive insulin release in obese patients

SYSTEMATIC REVIEW REPORT 3
results in increased sodium retention causing fluid expansion of blood volume predisposing the
patient to hypertension. The total cholesterol increase causes an increase in the formation of
cholesterol stones while hyperlipidemia causes fatty liver disease that may progress to liver
cirrhosis or fibrosis (Di Ciaula et al., 2019).
Such complications can be averted by lifestyle interventions, pharmacological and/or
surgical interventions (Bosello, Donataccio, & Cuzzolaro, 2016). While lifestyle changes may be
the gold standard used in managing obesity due to excessive caloric intake, its effectiveness
remains questionable because it is dependent on patient motivational factors. Bariatric surgery
has gradually become a common intervention strategy for obese patients (Qi et al., 2017). It is
more likely to yield objective results. The surgical intervention entails alteration to the digestive
tract to minimize the absorption of ingested foods. There are different types of bariatric surgery
such as bypass surgery, sleeve gastrectomy, and gastric banding (Carpentier, 2016). The
successes of the following surgery are relatively unknown in comparison to lifestyle
intervention.
Justification
The number of obese patients is constantly rising each year predisposing more people to
potentially fatal health complications. While lifestyle interventions such as changes in diet and
increasing physical activity are considered the gold standard for the management of obesity
caused by excess caloric intake, it takes months to attain results, some patients may not adhere
and there is a possibility of relapse after the intervention. Definitive measures such as surgery
can, therefore, be explored as a remedy to obesity. A majority of the articles present to conduct a
systematic review to determine the effectiveness of bariatric surgery in managing type 2 diabetes
and obstructive sleep apnea. Additionally, the studies show that there is a higher likelihood of
post-surgical complications in obese patients with comorbidities (Ashrafian et al., 2015).
Therefore, it is worth investigating if bariatric surgery can be used earlier on before obesity-
related complications set in.

SYSTEMATIC REVIEW REPORT 4
Statement of problem/ Research question
To address this gap a systematic review is required to determine the effectiveness of
bariatric surgery compared to lifestyle interventions in achieving a reduction in Body Mass Index
in the target population of obese patients without comorbidities.
Significance
The implementation of surgery as a definitive/ first-line treatment option may greatly
favor older obese patients that may not be physically capable to effect behavioral intervention
such as moderate to vigorous exercise. The use of the surgery may greatly favor obese patients
whose primary cause of excessive weight gain is clinical depression or associated with it.
Additionally, mortality associated with treating complications such as cholesterol stones with
cholecystectomy can be avoided (Augustin et al., 2017).
Objectives
The objectives set are specific, measurable, achievable, realistic and timely as follows :
 To compare the reduction of body mass index in the intervention group versus the control
group
 To determine how long it took the control group to achieve a reduction in body mass
index compared to the control group
 To determine the prevalence of complications that may occur in the intervention group in
comparison to the control group

SYSTEMATIC REVIEW REPORT 5
Body
Methodology
The methodology used is a set of criteria used to select relevant papers and exclude any
chances of bias to favor a specific result (Korstjens & Moser, 2017). It is achieved by
determining the eligibility criteria, the information databases are selected, the search strategy
used in the databases and points of biases in selection and specific studies (Smith et al., 2011).
The researchers then use a PRISMA chart to determine the final articles selected for
consideration of result reporting. The methodology to be used is as follows:
Determining the inclusion and exclusion criteria. This determines what articles will be
selected and involves coming up with criteria defined by the process taken to develop the
research question (Siddaway, Wood, & Hedges, 2019). The inclusion criteria will, therefore,
comprise specific participants, interventions, control groups, outcomes, environment and the
study designs used. The inclusion criteria to be used in the systemic review will be obese adult
patients without comorbidities, bariatric surgery (can include bypass surgery, gastric banding or
sleevectomies), and reduction of body mass index, post-surgical complications, and the study
designs assessed can be experimental or observational. The exclusion criteria will include obese
patients with diabetes type 2, sleep apnea or any other comorbidities or complications.
Information sources. The information sources used will be peer-reviewed articles, unpublished
articles and gray literature sources to increase the information pool thereby minimizing any
likelihoods of bias (Siddaway et al., 2019). The peer-reviewed articles will be obtained from
PubMed, Ovid, ScienceDirect, and Cochrane. Unpublished articles will be obtained from the
Clinical Trials.gov and the International Clinical Trials Registry Platform.
Search. The search involves developing a search strategy that ensures the search is accurate and
efficient (Siddaway et al., 2019). The search strategy put in place is to identify keywords, index
terms, and free text words. The keywords from the research question obtained are “bariatric
surgery” “lifestyle interventions” “reduction in Body Mass Index” “obese patients.” Subject
terms within each of the databases used, which are PubMed, Ovid, Cochrane, and ScienceDirect
are to be identified and used during the search. Truncated searches will be used to identify any
term variations in the database. For example, the use of “effect-” may give effectiveness or

SYSTEMATIC REVIEW REPORT 6
effectivity. In the search, Boolean operators will be used to associate two concepts (Siddaway et
al., 2019). The search intends to focus on bariatric surgery, in general, the three types can all be
included as well as the different nomenclature for lifestyle intervention. Therefore, the Boolean
operator “or” will be used. Additionally, the Boolean operator “not” will be used with type 2
diabetes to limit the search to obese patients without complications or comorbidities. The limit
set will be no articles from greater than ten years ago will be considered. A logic grid will be
designed as follows.
Population Intervention Control group Outcomes
1. Obese
patients
2. People
with
obesity
1. Bariatric
surgery
2. Gastric band
3. Gastric
sleeve
4. Gastric
bypass
1. Lifestyle
interventions
2. Behavioral
interventions
3. Nutritional
intervention
4. Physical
activity
1. Weight loss
2. Body mass index
reduction
3. Complications
4. Post-surgical
complications
The final search question will then be input into the database and the search process
documented
The search words were input and the following was generated from the PubMed database.
The process is to be repeated with the other sources.

SYSTEMATIC REVIEW REPORT 7
Study selection. This process involves the collection of all the studies that arise, screening the
abstracts for the availability of full article access, using the set inclusion /exclusion criteria to
pick relevant studies and finally reviewing references in each of the studies to reduce chances of
repetition of information due to a similar source. The PRISMA flow chart is used (Tricco et al.,
2018).

SYSTEMATIC REVIEW REPORT 8
Articles identified through
PubMed, Cochrane, Ovid and
ScienceDirect search (n=)
Articles remaining after duplicates are
removed (n=)
Articles screened using
abstracts and titles (n=)
Articles excluded (n=)
Full articles assessed under
eligibility criteria (n=)
Final articles included in the
systematic review (n=)
Critical Appraisal/ Bias. The risk of bias in each study will be assessed as well as the risk of
bias across the entire study. Bias risk will be assessed at the level of study design, method, and
analysis. Selection bias will be addressed by assessing the randomization of participants and
articles selected. Performance bias has to be addressed by assessing whether or not the
participants of a clinical trial were blinded to the study. Attrition bias is addressed by assessing
whether all participants that were at the beginning of a study were included in the results. The
statistical appraisal done for each article will assess the sample size used, whether any statistical
assumptions were made and how type 1 and type 2 errors were avoided (Siddaway et al., 2019).
Articles identified through gray
information and other sources
(n=)
Full articles excluded
(n=)

SYSTEMATIC REVIEW REPORT 9
Results
Data extraction. The relevant characteristics of the studies in the articles included will be
reported in the final systematic review such as population, intervention, control, outcomes, and
study design. The data will then be recorded as a measure of effect. The data is extracted in this
research is continuous i.e. weight or reduction in body mass index. Therefore the mean reduction
in body mass index or weight will be reported for each of the two groups (Sun, Zhou, Zhang, &
Liu, 2019). The p values and confidence intervals of each study will be assessed to determine the
statistical significance of the results generated.
Data synthesis. A meta-analysis will be done to assess for weighted mean in cases of varying
results (Siddaway et al., 2019). Forest plots will be constructed to display the weighted averages
against their confidence intervals. A standard chi-squared test and I square statistic will be used
to assess the meta-analysis done
Discussion
The findings will be discussed as per the results obtained in an impartial manner. The strengths
gaps identified while conducting the study will be mentioned and recommendations for
incorporation into practice or the necessity for further research will be given (Siddaway et al.,
2019).

SYSTEMATIC REVIEW REPORT 10
Included articles
Endnote referencing software was used.
The article by (Ashrafian et al., 2015) conducted a systematic review of how effective
bariatric surgery was in comparison to non-surgical weight loss for the management of
obstructive sleep apnea. This study is relevant in giving a framework for the systematic review
design. Additionally, the literature contained in the article highlights the potential for a
complication after bariatric surgery due to associated comorbidities. This information was used
in formulating the research question, that while one of the indications for bariatric surgery is the
existence of comorbidities, it may not favor the outcomes.
(Burgess, Hassmen, & Pumpa, 2017) conducted a systematic review of the factors that
affect adherence to lifestyle intervention among obese patients. This information was used in
generating the research question because one of the factors that they cited was that an early
substantial loss of weight increased the chances of adherence to lifestyle interventions.
(Siddaway et al., 2019) addresses the relevance, limitations and basic framework on how
to conduct a systematic review. The information used was able to highlight concepts in the

SYSTEMATIC REVIEW REPORT 11
search such as truncation and use of Boolean operators. While only these three articles have been
discussed in detail information from a vast pool of articles has been used in generating the report.

SYSTEMATIC REVIEW REPORT 12
References
Ashrafian, H., Toma, T., Rowland, S. P., Harling, L., Tan, A., Efthimiou, E., . . . Athanasiou, T. (2015).
Bariatric Surgery or Non-Surgical Weight Loss for Obstructive Sleep Apnoea? A Systematic
Review and Comparison of Meta-analyses. Obes Surg, 25(7), 1239-1250. doi:10.1007/s11695-
014-1533-2
Augustin, T., Moslim, M. A., Brethauer, S., Aminian, A., Kroh, M., Schneider, E., & Walsh, R. M. (2017).
Obesity and its implications for morbidity and mortality after cholecystectomy: A matched
NSQIP analysis. Am J Surg, 213(3), 539-543. doi:10.1016/j.amjsurg.2016.11.037
Balakas, K., & Smith, J. R. (2016). Evidence-Based Practice and Quality Improvement in Nursing
Education. J Perinat Neonatal Nurs, 30(3), 191-194. doi:10.1097/jpn.0000000000000197
Bosello, O., Donataccio, M. P., & Cuzzolaro, M. (2016). Obesity or obesities? Controversies on the
association between body mass index and premature mortality. Eat Weight Disord, 21(2), 165-
174. doi:10.1007/s40519-016-0278-4
Burgess, E., Hassmen, P., & Pumpa, K. L. (2017). Determinants of adherence to lifestyle intervention in
adults with obesity: a systematic review. Clin Obes, 7(3), 123-135. doi:10.1111/cob.12183
Carpentier, A. C. (2016). Targeting the gut to treat obesity and its metabolic comorbidities: focus on
bariatric surgery - view from the chair. Int J Obes Suppl, 6(Suppl 1), S6-S7.
doi:10.1038/ijosup.2016.7
Chen, J. Y. (2016). Research as Profession and Practice: Frameworks for Guiding the Responsible Conduct
of Research. Account Res, 23(6), 351-373. doi:10.1080/08989621.2016.1196439
Di Ciaula, A., Garruti, G., Fruhbeck, G., De Angelis, M., de Bari, O., Wang, D. Q., . . . Portincasa, P. (2019).
The Role of Diet in the Pathogenesis of Cholesterol Gallstones. Curr Med Chem, 26(19), 3620-
3638. doi:10.2174/0929867324666170530080636
Korstjens, I., & Moser, A. (2017). Series: Practical guidance to qualitative research. Part 2: Context,
research questions and designs. Eur J Gen Pract, 23(1), 274-279.
doi:10.1080/13814788.2017.1375090
Paulus, G. F., de Vaan, L. E., Verdam, F. J., Bouvy, N. D., Ambergen, T. A., & van Heurn, L. W. (2015).
Bariatric surgery in morbidly obese adolescents: a systematic review and meta-analysis. Obes
Surg, 25(5), 860-878. doi:10.1007/s11695-015-1581-2

SYSTEMATIC REVIEW REPORT 13
Qi, L., Guo, Y., Liu, C. Q., Huang, Z. P., Sheng, Y., & Zou, D. J. (2017). Effects of bariatric surgery on
glycemic and lipid metabolism, surgical complication and quality of life in adolescents with
obesity: a systematic review and meta-analysis. Surg Obes Relat Dis, 13(12), 2037-2055.
doi:10.1016/j.soard.2017.09.516
Siddaway, A. P., Wood, A. M., & Hedges, L. V. (2019). How to Do a Systematic Review: A Best Practice
Guide for Conducting and Reporting Narrative Reviews, Meta-Analyses, and Meta-Syntheses.
Annu Rev Psychol, 70, 747-770. doi:10.1146/annurev-psych-010418-102803
Smith, V., Devane, D., Begley, C. M., & Clarke, M. (2011). Methodology in conducting a systematic review
of systematic reviews of healthcare interventions. BMC Med Res Methodol, 11(1), 15.
doi:10.1186/1471-2288-11-15
Sun, X., Zhou, X., Zhang, Y., & Liu, H. (2019). Reporting and Methodological Quality of Systematic
Reviews and Meta-Analyses of Nursing Interventions in Patients With Alzheimer's Disease:
General Implications of the Findings. J Nurs Scholarsh, 51(3), 308-316. doi:10.1111/jnu.12462
Tricco, A. C., Lillie, E., Zarin, W., O'Brien, K. K., Colquhoun, H., Levac, D., . . . Straus, S. E. (2018). PRISMA
Extension for Scoping Reviews (PRISMA-ScR): Checklist and Explanation. Ann Intern Med, 169(7),
467-473. doi:10.7326/M18-0850