Systematic Literature Search - Emmanuel Ekpor

Master the art of comprehensive literature searches with our detailed slides on "Systematic Literature Search."
This presentation covers:

1) The importance of systematic literature searches in evidence synthesis
2) Key steps in planning and conducting a systematic literature search
3) Developing a search strategy: defining research questions and selecting keywords
4) Utilizing databases and search engines effectively (e.g., PubMed, Cochrane Library, Scopus)
5) Managing search results and screening for relevant studies
6) Practical tips for optimizing search sensitivity and specificity
7) Common challenges and solutions in literature searching

Ideal for researchers and practitioners involved in systematic reviews, these slides provide essential guidance for conducting thorough and effective literature searches.
Enhance the quality and reliability of your systematic reviews with robust literature search techniques.

1. Conducting Systematic
Literature Searches
EMMANUEL EKPOR
Research coordinator
Diabetes In Africa Knowledge Integration Network (DAKIN)
31 August 2024

2. Objectives
•What the search entails
•Where to search
•How to search
•How to manage and report the search

3. What is a systematic literature search?
It is a well thought-out and organized search for all (nearly
all) the literature published on a topic.
The search process should be carefully planned and
executed to ensure comprehensive and unbiased retrieval
of relevant studies or information.

4. A systematic search is the heart of a systematic review

5. •Leverage knowledge of expertise
•Identify previously published systematic reviews relevant
to your topic and use its search strategy as a guide
•Consider the availability of access to data sources
Beginning the process

6. Sources of data
•Databases
•Grey literature (dissertation repositories,
professional or governmental website, etc.)
•Hand searching of reference list

7. Databases
•Common Databases: PubMed, Medline, Cochrane Library,
CINAHL, Scopus, Web of Science
•Field-specific: PsycINFO, LitCovid, AMED - Allied and
Complementary Medicine
•Region-specific: AJOL, AIM

8. Search process
Keywords
/concept
Synonyms
Word
variations
Index
terms
String Test RefineExecute
Boolean operators ‘OR’ ‘AND’

9. Keywords/concepts
Can be identified from a well defined review question (i.e. guided by relevant framework)
Review type Framework
Effectiveness Population, Intervention, Comparator/s,
Outcomes
(PICO)
Experiential (Qualitative)Population, Phenomena of Interest, Context
(PICo)
Prevalence and/or
Incidence
Condition, Context, Population (CoCoPop)

10. What is the prevalence of obesity among children in
Africa?
Identify the main concept(s) or keywords in the research
question below

11. What is the prevalence of obesity among children in Africa?
FrameworkKeyword
/concept
Synonyms Word variationPhrase Index term
for PubMed
ConditionObesityObese, morbid
obesity
overweight,
etc.
Obes* = obese
and obesity
“morbid obesity” Obesity[Mesh]
Context AfricaAfrican, sub-
Saharan Africa,
SSA etc.
Afric* = Africa
and African
“sub-Saharan Africa”Africa[Mesh]
PopulationChildrenChild, infant,
pediatric, etc.
P?ediatric =
pediatric and
paediatric
Child* = child and
children
Child[Mesh]
NB: Spelling variation (?) is not applicable in PubMed

12. Phrase and word variations
•Phrases “ ”
Example: “lung cancer” “chronic noncommunicable disease”
•Spelling variation ?
Example: O?dema will return results for odema and oedema
•Variation in word endings (truncation *)
Example: educat* will return results for "educate", "education",
"educational", "educator", and so on.
NB: Spelling variation (?) is not applicable in PubMed www.pubmed.gov

13. Finding the Index Term
Index Terms
www.pubmed.gov
These are terms that has been indexed in a database to find records
specifically related to the topic of interest.

14. Combine terms with
OR
Obesity
Obese
Use “OR” to combine interrelated terms or similar concepts
Overweight
OR OR

15. Combine terms with
AND
Obesity
Children
Use “AND” to combine distinct concepts
Africa
AND AND

16. ConceptSearch string Records
#1 Obesity[Mesh] OR obesity OR obese OR obes* OR
“morbid obesity” OR overweight
#2 Africa[Mesh] OR Africa OR African OR Afric* OR “sub-
Saharan Africa” OR SSA
#3 Children[Mesh] OR Children OR child OR child* OR
infant OR infancy OR infan* OR pediatric
#4 #1 AND #2 AND #3
Building the search string
www.pubmed.gov
What is the prevalence of obesity among children in Africa?

17. Refining a search
This involves adjusting your search strategy to make it
more specific or focused, thereby improving the relevance
and quality of the search results.
•Check the correct use of keywords, relevant synonyms,
phrases “ ”, truncation * $, word variation wildcards ? #, and
Boolean operators OR, AND, NOT
•Adjust the search by using field tags such as title [ti] and
abstract [ab]

18. Refined search strategy with filed tag [tiab] applied
ConceptSearch string Records
#1 Obesity[Mesh] OR obesity[tiab] OR obese[tiab] OR
obes*[tiab] OR “morbid obesity”[tiab] OR
overweight[tiab]
#2 Africa[Mesh] OR Africa[tiab] OR African[tiab] OR
Afric*[tiab] OR “sub-Saharan Africa”[tiab] OR SSA[tiab]
#3 Children[Mesh] OR Children[tiab] OR child[tiab] OR
child*[tiab] OR infant[tiab] OR infancy[tiab] OR
infan*[tiab] OR pediatric[tiab]
#4 #1 AND #2 AND #3

19. ((Obesity[Mesh] OR obesity[tiab] OR obese[tiab] OR
obes*[tiab] OR "morbid obesity"[tiab] OR overweight[tiab])
AND (Africa[Mesh] OR Africa[tiab] OR African[tiab] OR
Afric*[tiab] OR "sub-Saharan Africa"[tiab] OR SSA[tiab])) AND
(Children[Mesh] OR Children[tiab] OR child[tiab] OR
child*[tiab] OR infant[tiab] OR infancy[tiab] OR infan*[tiab]
OR pediatric[tiab])
Alternative way of reporting the search string

20. Managing the search records
•Document all the search records
•Download the records
•Store the records in a recognizable folder

21. Reporting the search
Method section
•Where you searched
•When the search was conducted
•Who conducted the search (this is crucial especially if the search was conducted by
a librarian or information specialist).
•Keywords/concepts on which the search was built on
•Was it informed by previous systematic review
•Boolean operators used
•What limits/filters were applied
•What other supplementary search were employed (.e.g. hand search, backward and
forward tracing)
•Was the search updated along the line

22. Example
A systematic literature search strategy was designed by a medical librarian [JB] in consultation with the
principal investigator [EE]. The search was conducted on PubMed, MEDLINE (via Ovid), and Embase (via
Ovid), from their inception to August 2, 2022. The search strategy was guided by the CoCoPop
framework; a widely used literature search-informed strategy for systematic review of prevalence or
incidence. The framework consists of three key domains, the (Co) condition, (Co) context and (Pop)
population of study which were framed as (“obesity”), (“Africa”), and (“children”), respectively. Index
terms (.e.g. MeSH for PubMed) were blended with the keywords and their respective variations to
balance the sensitivity and specificity of the search strategy. Boolean combinations (AND, OR) were also
applied.The electronic searches were not limited to language or date. In addition to the database search,
the reference lists of the retrieved articles were systematically reviewed to identify any additional relevant
studies. The full details of the search strategy are provided in appendix 1.

23. Result sectionPRISMA flow chart


















Records identified through database
searching (PubMed=, Medline=,
Embase =)
Total (n=)

Screening


Included

Eligibility

Identification
Additional records identified through
AJOL and reference screening (n =)
Records screened
(n =)
Duplicates removed
(n =)
Full-text articles assessed for
eligibility (n =)
Studies included in qualitative
synthesis (n=)
Records excluded
(n =)
Full-text articles excluded
(n =)
Reasons for exclusion
• Review article (n=)
• BMI misclassified/not defined (n=)
• Adult participants (n=)
• No prevalence data (n=)
• Non-English article (n=)
• Inconsistent data (n=)
• No full text (n=)


Studies included in meta-
analysis (n=)

24. Thank you
Ekpor E

25. •Batten, J., & Brackett, A. (2021). Ensuring the rigor in systematic reviews: Part 3, the value of
the search.Heart & lung : the journal of critical care,50(2), 220–222.
•Munn, Z., Stern, C., Aromataris, E., Lockwood, C., & Jordan, Z. (2018). What kind of systematic
review should I conduct? A proposed typology and guidance for systematic reviewers in the
medical and health sciences.BMC medical research methodology,18(1), 5.
•PubMed User Guide. Accessed July 28, 2021. Available from
https://pubmed.ncbi.nlm.nih.gov/help/
References

26. Trial Questions
Experience of stigma among people with HIV in Africa
Develop a PubMed search strategy for a study which seeks
to synthesize the evidence on the:
ConceptSearch string Records
#1
#2
#3
#4 #1 AND #2 AND #3