Sources of evidence

When looking for evidence, there are many sources you can use.


Academically or commercially published evidence

This can be found from a number of sources:

  • Primary sources – for example journals/e-journals, books/e-books
  • Databases – searchable bibliographic databases which contain details of the authors, publication details and abstracts of published works.  They do not contain publications but may link to the full text.  Generally, databases will have a particular subject focus.  
  • Discovery systems – a database that draws references from multiple databases and resources.  Libraries will often utilise discovery systems.    

Grey literature

This is information produced by organisations which are outside the commercial or academic publishing and distribution channels and are, therefore, not normally included in the databases.

Generally grey literature publication types include:

  • reports,
  • working papers,
  • government documents, etc.

Organisations that produce grey literature include:

  • government departments and agencies,
  • charities,
  • non-governmental organisations,
  • academic centres and departments, and
  • private companies and consultants.

Key databases

The CSP subscribes to the databases listed below. They can be searched individually or searched altogether by the CSP's WorldCat Discovery platform .


  • Key features: MEDLINE is the world's best-known biomedical and clinical science database. It is widely recognized as the premier source for bibliographic and abstract coverage of biomedical literature.
  • Covers: journal citations and abstracts, some links to full text
  • Thesaurus: NLM Medical Subject Headings (MeSH).

Cinahl Plus (Cumulative Index to Nursing and Allied Health Literature).

  • Key features: CINAHL provides coverage of the literature related to midwifery, nursing, occupational therapy, physiotherapy, podiatry, health education and other related subject areas.  ‘Plus’ means the CSP subscribes to a version with links to additional full text.
  • Covers: journal articles, some healthcare books, nursing dissertations, selected conference proceedings, standards of practice, audiovisuals and book chapters.
  • Thesaurus: Cinahl Headings

AMED (Allied and Complementary Medicine)

Key features: AMED indexes a selection of journals in complementary medicine, palliative care and several professions allied to medicine including physiotherapy, occupational therapy, podiatry and rehabilitation.

  • Covers: journal citations and abstracts
  • Thesaurus: NLM Medical Subject Headings (MeSH)


Key features: SportDiscus is an authoritative bibliographic database covers key areas of sports medicine and related fields. Content areas range from sports physiology and sports psychology to physical education and recreation.

  • Covers: journal citations and abstracts
  • Thesaurus: Sport (SIRC) Thesaurus                                                                                                                                                                                                                                                                   Find out more about other specialist databases with free access

Key Discovery systems

CSP's WorldCat Discovery

  • Key features: A single search is run in all the databases below and the results presented as a single list of references
  • Covers: Medline, AMED, Cinahl Plus, SportDiscus, e-books and the CSP Library catalogue
  • Thesaurus: free text searching

Cochrane library 

Key features: The Cochrane Library is known as the home of Cochrane Reviews, the "gold standard" systematic reviews in healthcare interventions. It also contains information about other systematic reviews, randomised controlled trials, economic evaluations and health technology assessments.

  • Covers: Cochrane Database of Systematic Reviews, Central Register of Controlled Trials and Methodology Register; Database of Abstracts of Reviews of Effects, Health Technology Assessment Database and NHS Economic Evaluation Database.

Also includes Cochrane Clinical Answers – short answers to clinical questions with evidence from relevant Cochran Reviews (free to UK institutions)

  • Thesaurus: NLM Medical Subject Headings (MeSH)

Turning Research Into Practice (TRIP)

Key features: TRIP is a clinical search engine designed to allow users to quickly and easily find and use high-quality research evidence to support their practice and/or care.

  • Covers: not specified
  • Thesaurus: free text searching

Physiotherapy Evidence Database (PEDro)

  • PEDro is a free database of over 26,000 randomised trials, systematic reviews and clinical practice guidelines in physiotherapy.  The quality of randomised trials is independently assessed using a scale known as the PEDro scale
  • Covers: randomised trials, systematic reviews and clinical practice guidelines in physiotherapy
  • Thesaurus: free text searching

Key grey literature sources

NHS Evidence

  • Covers: clinical and public health guidance, government policy, patient information, drug information, systematic reviews, primary research, clinical knowledge summaries, grey literature, and clinical knowledge summaries

National Institute for Health and Care Excellence (NICE)

  • Covers: clinical, public health and social care guidelines; medicines practice guidelines; technology appraisals; medical technologies, diagnostics and interventional procedures guidance and quality standards.

Scottish Intercollegiate Guidelines Network (SIGN)

  • Covers: evidence based clinical practice guidelines for the National Health Service (NHS) in Scotland.

CSP Library Catalogue(FOLIO)

  • Covers: a significant collection of grey literature relevant to physiotherapy. A wide range of material relevant to physiotherapy much of it available digitally.

Learning how to use databases and discovery systems

Your search for evidence will be more effective and efficient if you understand how to use them.  Although there are similarities, each system has strengths and weaknesses, and it’s  worth spending a little time familiarising yourself with how to best use the ones you regularly search. 

You will find tutorials on many of the websites hosting databases or discovery systems.

Find out more

Which sources of evidence should I use?

This depends on:

  • Why you are looking for the evidence
  • How much time you have
  • The question you are trying to answer

Ideally, if you want to find the best evidence you would search a variety of sources.  In reality, you may only have enough time to try one source and need to choose the one which is most likely to quickly find you the best evidence.  

Understanding how to efficiently search the source of evidence you have chosen will save you valuable time.

Let’s consider the questions developed in the evidence-based practice tools and why you may or may not select specific source(s) of evidence.

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