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Nursing and Public Health: Literature Searches & Reviews

If you do not have a full research question you can start with a pre-search to help you develop into a question. If you start with a general topic of interest (e.g. dementia and end-of-life care) you can do a quick search on your know elements and scan your results for themes to explore further in your question e.g. if pain management seems to be recurring as a general theme in your pre-search results this shows that articles are available on this topic and your question could be developed to incorporate this idea e.g. What are nurse's experiences of pain management for dementia patients in end-of-life care?

TIP! Your next step would be to do a full structured search.

Using the PICO framework to develop your research question

The PICO model is used widely in nursing and health research and in professional practice and is strongly advocated by the NHS. This method will help you formulate an answerable question and identify key concepts. PICO will also help you develop your inclusion and exclusion criteria. You should refer back to these when you are making your final selection of articles. 

Population - This may require more than one search string (e.g. dementia patients in an acute setting)

Intervention or exposure - This element is usually the easiest to define and where you should start your search.

Outcomes - These are often not easy to define (e.g. improving patient care) and a search string may sometimes not be required in order avoid over specificity

A literature search focuses on a single topic or research question which aims to cover all the available research relating to the question. It is conducted using one or more databases, and requires the use of appropriate search terms with synonyms, related terms etc. It also includes an audit trail (usually presented in a table) showing how you refined your results and arrived at your final articles.

Traditional literature reviews are those where researchers have sought to organize existing knowledge and publish summary of a variety of topics. They are useful for background reading and gathering information on a specific topic.

Evidence Hierarchy

Top of hierarchy

Secondary research (pre-appraised and synthesized)

  • Evidence based guidelines
  • Systematic reviews (syntheses of existing studies)

Primary research (original first hand research)

  • Single large group study e.g. Randomised Controlled Trials (RCTs)
  • Other groups studies e.g. observation studies
  • Case study or report
  • Background information or expert opinion

Evaluating Results

  • Once the database limits and filters have been applied you may have anything between 20 and 100 results. If you end up with over 100 it may be best to refine again (see Step 6).
  • Now check your results for titles that look relevant and exclude those which are not relevant.
  • Apply the inclusion and exclusion criteria that relate to your PEO or PICO statements e.g. ensure you select papers relating to the chosen population or setting.
  • If you struggle to think of exclusion criteria, assess why you think an article doesn't fit and ask yourself why. The "why" is the exclusion criterion.
  • Do the articles relate to the United States? If the article is from an international journal is it still may be applicable, but you will need to make sure before using these articles.
  • Check the research methodologies and design of your articles - quantitative papers are likely to take the form of RCNs or cohort studies based around experiments or interventions while qualitative papers may be grounded theory, phenomenological or ethnographic studies which look predominantly at people’s experiences.

TIP!  Check the methodologies used in the facet analysis sections of the dissertations (find these on the start page of this guide) for essential guidance in making your final selection of papers. This shows how to sift your results by applying your inclusion and exclusion criteria to the results found in each database.

A systematic review is a review of a clearly formulated question that uses systematic and explicit methods to identify, select and critically appraise relevant research and to collect and analyze data from the studies that are included in the review (Cochrane Handbook, 2011).Often conducted by a team rather than a single researcher, it is not merely a descriptive summary of the studies you have chosen but should aim to do the following:

  • Focus on a single topic with strict criteria parameters and consistent methodology.
  • Cover all the available research relating to the question.
  • Draw the evidence together and start to relate the studies together.
  • Combine findings across the studies and look for themes and patterns, similarities and overlaps and differences between the studies.
  • Draw together different study perspectives and recommendations for practice.
  • Acknowledge the study limitations as presented by the authors themselves or, alternatively, include an assessment of the strengths and weaknesses of the studies.
  • Examine, compare and summarize each piece of research identified.
  • Aim for a considered judgments and a balanced and unbiased conclusion.


NAU student with Kenya child

  1. Forming a Health Question - Students discover how to formulate a specific health question.
  2. Choosing a Resource - Students identify a variety of  sources of information based on their understanding of how information is disseminated and consider choosing credible sources for information on their health question.
  3. Searching Resources -  Students learn how to search sources of information, optimizing search features when appropriate, such as Subject Headings and date limiters.
  4. Evaluating Resources - Students evaluate search results in relation to their health question.

CASP Tools, Critical Appraisal, and Critical Reading

Critical appraisal is the assessment of evidence by systematically reviewing its relevance, validity and results to specific situations.

The CASP (Critical Skills Appraisal Programme) website has a useful range of free downloadable resources which can help you structure your research strategy and help you shape your research criteria. The CASP Checklists can help you determine which studies to focus on and which match the criteria you have laid out for your systematic review. The critical appraisal tools are designed to be used when reading research and include the following:

  • Systematic Reviews
  • Randomised Controlled Trials
  • Cohort Studies, Case Control Studies
  • Economic Evaluations
  • Diagnostic Studies
  • Qualitative studies
  • Clinical Prediction Rule