Selecting Databases

Jump to Available Databases

Searching databases for published peer reviewed journal articles is a central part of the evidence synthesis process. It is good practice to search databases one at a time - each database has different limiters and content, combined searching can be ineffective or incomplete. The following diagram shows the type of content, and a rough idea of the overlap, of key databases.

Databases overlap

Image source: Wilding, H. (2020). Library website, St Vincent's Hospital Melbourne.

By searching more than one database, the review will increase in comprehensiveness while also minimising the bias that any single source will have. For interdisciplinary topics, choosing multiple databases is even more important, as it will broaden the net.

Which Platform?
A platform is a search interface. It may host individual databases or simply act as a search engine. Examples of a platform: EBSCOhost, Ovid, ProQuest, Google, TRIP. It’s important to report the database and platform being used when conducting a systematic review. Databases such as PsycINFO and Medline can be found on platforms such as EBSCOhost, OVID or ProQuest. Someone trying to replicate your PsycINFO EBSCOhost search on PsycINFO Ovid will have a totally different selection of limiters and search tools and therefore may not be able to exactly replicate your search.

EBSCO Discovery Service (EDS) is an online research tool that “pulls together” almost all of our Library resources so that they can be explored using a single search box. In other words, rather than searching the Library Catalog for books and a database such as Medline for journal articles, you can do an EDS search and get results which include books, e-books, journal articles, and government documents in one list. In this way you could think of EDS as the Library’s version of Google. Generally for most day to day research needs this is the all in one service, however for those conducting a systematic review or other reviews for publication it is advised that individual databases be used.

Which Database?
Different databases cover different content areas, a list of databases we have access to is below.

Database	Platform	Discipline	Description
Cochrane Library		Medicine, Healthcare	The Cochrane Library consits of: - The Cochrane Database of Systematic Reviews (Cochrane Reviews). Contains all the peer-reviewed systematic reviews and protocols (Cochrane Protocols) prepared by the Cochrane Review Groups. - The Cochrane Central Register of Controlled Trials (CENTRAL). CENTRAL is a database that contains details of articles of controlled trials and other studies of healthcare interventions from bibliographic databases (majorly MEDLINE and EMBASE), and other published and unpublished sources that are difficult to access, including trials from the trial registries. - Cochrane Clinical Answers. These evidence summaries on a variety of questions of interest to healthcare professionals have a user-friendly presentation with graphics and high-level conclusions of the research evidence based on Cochrane Reviews.
Embase	Ovid	Biomedicine, Pharmacology	European equivalent of Medline. Embase is a great research literature resource that includes RCTs. It is especially good for pharmacology information. Embase (Excerpta Medica Database) is a biomedical and pharmacological database produced by Elsevier B.V., containing more than 30 million records including articles from more than 8,500 journals published world-wide. It contains bibliographic records with citations, abstracts, and indexing derived from biomedical articles in peer reviewed journals, and is especially strong in its coverage of drug and pharmaceutical research, pharmacology, and toxicology. It also covers clinical medicine and its specialties, and medical devices. Embase covers some unique content not indexed by MEDLINE.
Emcare	Ovid	Nursing, Allied Health	Emcare is a nursing and allied health database. It contains over 5 million records dating from 1995 form international journals and books, over 1,800 of which are not available from other nursing databases. Its coverage includes nursing, community practice, healthcare information and management, nutrition and dietetics, occupational health, physiotherapy, psychology, rehabilitation, and social medicine.
Europe PMC		Biomedical	Europe PMC is a repository, providing access to worldwide life sciences articles, books, patents and clinical guidelines. Europe PMC provides links to relevant records in databases such as Uniprot, European Nucleotide Archive (ENA), Protein Data Bank Europe (PDBE) and BioStudies.
Google Scholar		Mulitdisciplinary	Google Scholar searches academic publishers, professional societies and pre-print archives. Don't forget to turn on library access in Settings > Library Links > search South West Healthcare. Google Scholar can be useful as a supplemental source but it has limitations as an evidence synthesis database. Limitations inculde reporducibility, no controlled vocabulary, and not being able to export resources in bulk to list a few. On the positive site grey literature sources are often uncovered using Google Scholar, and it can be the easiest way to locate known items and retrieve the full text.
Informit Health Collection		Health	Australian focus. Supporting the professional practice of evidence-based treatment, this collection features comprehensive coverage of key disciplines across all aspects relevant to nursing, general, specialist and allied health. Coverage: Full text: 1977-onwards
MedRxiv		Health	medRxiv (pronounced "med-archive") is a free online archive and distribution server for complete but unpublished manuscripts (preprints) in the medical, clinical, and related health sciences. Preprints are preliminary reports of work that have not been certified by peer review. They should not be relied on to guide clinical practice or health-related behavior and should not be reported in news media as established information.
Medline	Ovid	Medicine, Healthcare	MEDLINE is the U.S. National Library of Medicine's database covering the international literature on biomedicine, including the allied health fields and the biological and physical sciences, humanities, and information science as they relate to medicine and healthcare. Information is indexed from approximately 5,600 journals published world-wide. Records start in the early 1800's and is updated daily. Combines the National Library of Medicine's bibliographic database with links to the complete text of articles from leading medical journals. Large health / medical database that is a great resource for all research literature including randomised control trials (RCTs).
PsycInfo	Ovid	Psychology	The PsycINFO database provides abstracts and citations to the scholarly literature in the psychological, social, behavioural, and health sciences. The database includes material of relevance to psychologists and professionals in related fields such as psychiatry, management, business, education, social science, neuroscience, law, medicine, and social work. Updated weekly, PsycINFO provides access to journal articles, books, chapters, and dissertations. Main psychology database developed by the American Psychological Association.
PubMed		Biomedical, Life sciences	Citation Database - You should use at least one citation database for your search and for key article cross-checking. PubMed comprises more than 27 million citations for biomedical literature from MEDLINE, life science journals, and online books. PubMed is a free resource that is developed and maintained by the U.S. National Library of Medicine. It also contains some search features useful for quickly searching for high quality evidence.
Trip Database			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
Directory of Open Access Journals		Multidisciplinary	Articles from open access journals
Grey Literature		Multidisciplinary	See our library Grey Literature section for further information and list of resources.

What does the literature say we should use?

Optimal database combinations for literature searches in systematic reviews: a prospective exploratory study.

Abstract

BACKGROUND:

Within systematic reviews, when searching for relevant references, it is advisable to use multiple databases. However, searching databases is laborious and time-consuming, as syntax of search strategies are database specific. We aimed to determine the optimal combination of databases needed to conduct efficient searches in systematic reviews and whether the current practice in published reviews is appropriate. While previous studies determined the coverage of databases, we analyzed the actual retrieval from the original searches for systematic reviews.

METHODS:

Since May 2013, the first author prospectively recorded results from systematic review searches that he performed at his institution. PubMed was used to identify systematic reviews published using our search strategy results. For each published systematic review, we extracted the references of the included studies. Using the prospectively recorded results and the studies included in the publications, we calculated recall, precision, and number needed to read for single databases and databases in combination. We assessed the frequency at which databases and combinations would achieve varying levels of recall (i.e., 95%). For a sample of 200 recently published systematic reviews, we calculated how many had used enough databases to ensure 95% recall.

RESULTS:

A total of 58 published systematic reviews were included, totaling 1746 relevant references identified by our database searches, while 84 included references had been retrieved by other search methods. Sixteen percent of the included references (291 articles) were only found in a single database; Embase produced the most unique references (n = 132). The combination of Embase, MEDLINE, Web of Science Core Collection, and Google Scholar performed best, achieving an overall recall of 98.3 and 100% recall in 72% of systematic reviews. We estimate that 60% of published systematic reviews do not retrieve 95% of all available relevant references as many fail to search important databases. Other specialized databases, such as CINAHL or PsycINFO, add unique references to some reviews where the topic of the review is related to the focus of the database.

CONCLUSIONS:

Optimal searches in systematic reviews should search at least Embase, MEDLINE, Web of Science, and Google Scholar as a minimum requirement to guarantee adequate and efficient coverage.

Bramer, W. M., Rethlefsen, M. L., Kleijnen, J., & Franco, O. H. (2017). Optimal database combinations for literature searches in systematic reviews: a prospective exploratory study. Systematic reviews, 6(1), 245.

Search Filters

Systematic Reviews Subset on PubMed

This strategy is intended to retrieve citations identified as systematic reviews, meta-analyses, reviews of clinical trials, evidence-based medicine, consensus development conferences, guidelines, and citations to articles from journals specializing in review studies of value to clinicians. This filter can be used in a search as systematic [sb].

PubMed Subject Filters

Flinders Filters

Search filters are evidence based literature search strategies, developed using an explicit methodology and tested using a gold standard test comparison study design and detailed in published papers. Each provides a standardised, systematic subject-based search with a known level of performance. Embedding the search filter into a URL for a database such as PubMed provides the searcher with access to a highly performing literature search simply by clicking a link. Examples: Aboriginal and Torres Strait Islander Health, Palliative care, and Primary Health Care.