This pages includes guidance for developing a SR search strategy. See the Search Techniques page of this guide for information on using Boolean (AND and OR) and controlled vocabulary (e.g MeSH) for building the search.
Search Process
PubMed and Ovid Medline are both MEDLINE. You only need to search one or the other. Not both.
For an up-to-date SR with the most recent literature, the search should be repeated before the final analysis in order to capture literature that was published since the initial search.
A well designed SR search strategy should be sensitive enough to capture all relevant literature, which means that it will also retrieve a higher proportion of irrelevant results. It is normal for a SR search strategy to retrieve hundreds or thousands of results that do not meet the eligibility criteria. This part of the process. The SR team will identify the relevant articles during title & abstract screening and full-text review.
- Documenting a Search Tutorial USC Libraries tutorial on documenting a search for a systematic review
Create a Search Strategy from a PICO Question
A well-formulated PICO question will help you to identify the main concepts for your search strategy. PICO is a framework for breaking down a research question into its component parts. PICO works best for intervention based studies.
For more information about PICO: The Evidence-based Practice Guide
In most cases:
- NOT all PICO elements should be used in the search.
- Include P (population or problem).
- Include I (intervention).
- Include C only for direct comparisons of two specific interventions.
- Outcomes are usually NOT recommended to include in your search.
In most databases, you are searching the title, abstract, keywords and other citation data. You are not searching the full-text of the articles.
| PICO | Example | Include in search? |
|---|---|---|
| P (population) | Children/Adolescents | Yes |
| P (problem) | Acute Lymphoblastic Leukemia | Yes |
| I | Exercise and motor interventions in addition to medical intervention | Yes |
| C | Medical intervention without exercise and motor interventions | No |
| O | Physical activity and motor outcomes | No |
| Children AND Acute Lymphoblastic Leukemia AND Exercise |
| In this example, we can combine P (population) AND P (problem) AND I (intervention) with the Boolean operator AND to find literature with all three concepts. The C (comparison) and O (outcomes) with be analyzed during the review process. |
| PICO | Example | Include in search? |
|---|---|---|
| P | Patients with Choledocholithiasis | Yes |
| I | Endoscopic papillary dilation after Sphincterotomy | Yes |
| C | Sphincterotomy alone | Yes |
| O | Complete stone removal, adverse events, procedure time | No |
|
Strategy 1: choledocholithiasis AND endoscopic papillary dilation AND sphincterotomy Strategy 2: choledocholithiasis AND (endoscopic papillary dilation OR sphincterotomy) |
|
Strategy 1: Use this strategy if you only want literature that directly compares the intervention and comparison in a single study. Strategy 2: Use this strategy if you want literature that directly compares the intervention and comparison in a single study AND studies that examine sphincterotomy alone. Combining the intervention with the comparison with OR instead of AND broadens the search to find more literature. The best strategy will depend on your question and the literature available to answer your question. |
Tip! Develop search strategy on a text document and then copy and paste into databases.
- SR Search Template ExampleHere is an example of a template you can use to document your search strategy and search results. You and download and use this one or create one of your own.
Create a Search Strategy for Qualitative Evidence Synthesis
When conducting a qualitative evidence synthesis, SPIDER can be a useful framework for developing the concepts for your search strategy.
For more information about SPIDER: Beyond PICO: The SPIDER Tool for Qualitative Evidence Synthesis
In most cases:
- NOT all SPIDER elements should be used in the search.
- Include S (sample or population).
- Include PI (phenomenon you are interested in).
- Include D (design to retrieve the study types of interest)
- Evaluation and Research should not be included in the search design and instead should be evaluated during the screening phase
In most databases, you are searching the title, abstract, keywords and other citation data. You are not searching the full-text of the articles.
| SPIDER | Definition | Include in search? |
|---|---|---|
| S - Sample | Population | Yes |
| PI - Phenomenon of interest |
The how and why of certain behaviors, decidions, and individual experiences |
Yes |
| D - Design | Theoretical framework used in qualitative research | Yes |
| E - Evaluation | Outcome measures, e.g. attitudes and views | No |
| R - Research Type | Qualitative, quantitative or mixed methods | No |
Example Question: What are young parents’ experiences of attending antenatal education?
| SPIDER | Example | Include in search? |
|---|---|---|
| S - Sample | young parents | Yes |
| PI - Phenomenon of interest |
antenatal education |
Yes |
| D - Design | questionnaire, survey, focus groups | Yes |
| E - Evaluation | views, perceptions, experiences, | No |
| R - Research Type | Qualitative, quantitative or mixed methods | No |
| young parents AND antenatal education AND (questionnaire OR survey OR focus groups |
| In this example, we can combine S (sample) AND PI (phenomenon of interest) AND D (design) with the Boolean operators AND and OR to find literature with all three concepts. The E (evalutation) and R (research type) with be analyzed during the review process. |
Tip! Develop search strategy on a text document and then copy and paste into databases.
Synonyms and Relevant Terms for Each Concept
Gather synonyms and related terms for each concept.
- Types of synonyms and related words may include controlled vocabulary (e.g. MeSH), terms with similar meanings, alternative spellings, acronyms, both broad and specific terms, discipline-specific terms, and more.
- Find terms by viewing relevant literature, systematic reviews, and other information sources. Viewing the synonyms listed for controlled vocabulary (e.g. MESH entries) may help you locate relevant terms.
| Concept |
Search Strategy [each concept should include a combination of keywords and controlled vocabulary (when applicable) AND may include a combination of OR and AND boolean operators] |
|---|---|
| LGBTQ |
"Sexual and Gender Minorities"[Mesh] OR "Homosexuality"[Mesh] OR "Bisexuality"[Mesh] OR "Transgender Persons"[Mesh] OR homosexuality OR lesbian OR gay OR bisexual OR transgender OR queer |
| Nursing Education |
"Education, Nursing, Associate"[Mesh] OR "Education, Nursing, Baccalaureate"[Mesh] OR "Education, Nursing, Diploma Programs"[Mesh] OR "Education, Nursing, Graduate"[Mesh] OR "Students, Nursing"[Mesh] OR "Schools, Nursing"[Mesh] OR "Faculty, Nursing"[Mesh] OR Nursing education OR Nursing curriculum OR Nursing schools OR Nursing students OR Nursing faculty |
| Cultural Competency | "Healthcare Disparities"[Mesh] OR "Cultural Competency"[Mesh] OR "Culturally Competent Care"[Mesh] OR competent OR competence OR competency OR competencies |
Put it all together:
("Sexual and Gender Minorities"[Mesh] OR "Homosexuality"[Mesh] OR "Bisexuality"[Mesh] OR "Transgender Persons"[Mesh] OR homosexuality OR lesbian OR gay OR bisexual OR transgender OR queer) AND ("Education, Nursing, Associate"[Mesh] OR "Education, Nursing, Baccalaureate"[Mesh] OR "Education, Nursing, Diploma Programs"[Mesh] OR "Education, Nursing, Graduate"[Mesh] OR "Students, Nursing"[Mesh] OR "Schools, Nursing"[Mesh] OR "Faculty, Nursing"[Mesh] OR Nursing education OR Nursing curriculum OR Nursing schools OR Nursing students OR Nursing faculty) AND ("Healthcare Disparities"[Mesh] OR "Cultural Competency"[Mesh] OR "Culturally Competent Care"[Mesh] OR competent OR competence OR competency OR competencies)