What is a Quality Literature Search?
A quality literature search is a systematic survey of the literature, (published and unpublished), on a research topic or clinical question. It goes beyond a cursory search of the literature to selecting appropriate databases, creating a series of search queries using relevant keywords including controlled vocabulary keywords, reviewing each result, filtering out non-relevant results based on specific criteria, reading the full text content of the selected results and performing a critical appraisal of the literature to understand the context of a research topic or to answer a clinical question.
Components of a quality literature search include:
After completing a quality literature search, PACS students should have a thorough understanding of the topic, be able to demonstrate knowledge of the topic, provide original concepts to supplement or expand on the topic, and for clinical questions, be able to locate the best evidence for answering the question.
Where to Start?
For PACS students, there are typically two reasons for searching the literature; the first being to locate the best evidence for answering a clinical question, and secondly, to locate resources for a research-based question for capstone or independent study projects and other projects.
Literature Reviews for Clinical Questions
Searching of the literature for resources to answer clinical questions may benefit from using a PICO analysis. Use of a PICO analysis can help structure clinical-based questions into a framework for formulating search queries in order to retrieve optimal search results. The use of a PICO analysis stems from the concept of evidence-based medicine which is defined as “the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients” (see PICO Chart box). The first step in using a PICO analysis to identify the components of a clinical question into concepts based on each PICO element as noted on the PICO Chart.
The next step is to identify all known keywords such as controlled vocabularies or thesauri keywords including natural language keywords that relate to each PICO concept (see Keywords box). One recommended strategy for starting a search of the literature for clinical questions is to formulate individual search queries based on a single concept and combine the queries. Many databases (see Databases tab) allow for flexibility of combining multiple single keyword queries into a single search string. The idea is to experiment and “get your hands dirty” with various queries on different databases. Try out a search query using keywords from each PICO concept or limit to one keyword from a PICO concept. As each new query is tested out, document each query so that the same queries can be tested out in other databases. The same query will not produce the same results in different databases.
Literature Reviews for Research Questions
Searching the literature for research questions requires extensive review of the literature which is recommended for exploring topics for capstone and independent study projects. Once a capstone or independent study project topic or other research question is identified, the first step is to identify all known keywords that relate to the research question as done for clinical-based questions and develop queries using more than one database. Searching for a topic related to a capstone or independent study research project is a reiterative process and requires using multiple keywords to formulate queries and use of several databases.
Searching the literature is a skill that is best learned through trial and error. Practice with various databases to learn more about the nuances of each database. Experiment with different keywords such as author keywords, controlled vocabularies and natural language keywords to discover how various databases interpret the query. Review the keywords as noted for each work.
Do not get discouraged if results are not relevant to the query. Points to consider are:
PATIENT OR PROBLEM
Who is the patient or what is the problem? Include any characteristics that define the patient or population, age, gender, ethnicity, or age group.
What is the intervention? What is the therapy being considered?
Is there an alternative to compare with the intervention?
OUTCOMES OR EFFECTS
What is the outcome of interest? What is the effect of a particular intervention?