Sage Journals: Discover world-class research

Abstract

Laboratory medicine is strong in the basic scientific background that underpins the pathological rationale for considering the use of a test, as well as characterising analytical performance of laboratory procedures. Evidence of the impact of test utilisation on health outcomes and adding value to the patient’s care pathway is more limited. However, purchasers and commissioners of laboratory services, as well as clinicians, are bombarded with a burgeoning literature on new biomarkers and devices, against a backdrop of fiscal constraints. This increasingly critical appraisal of both current practice, as well as new developments, demands that all health professionals are up-to-date in the knowledge of their subject, as well as being able to access and impart this knowledge in real time to their colleagues in the clinical team. This requirement for knowledge means that the laboratory medicine professional can be asked to provide information at any time, from a host of differing scenarios, and with a considerable variation in the depth of response being required. Thus, the biochemist may need to respond to a query from the Emergency Department on the one hand, to preparing the justification for a new test – or disinvestment in an old (and now inappropriate) test, to writing the case for a research grant proposal. All of these scenarios require clarity in the question being asked, and the ability to search for the evidence across a wide range of resources. This review takes the reader through the steps to efficient retrieval of good quality information.

Keywords

Clinical studies laboratory medicine evidence-based practice information literacy

Introduction

Laboratory medicine procedures, often referred to as diagnostic tests, are tools used by clinicians to help make decisions, with the goal of improved outcomes.¹ Responsibility for these procedures lies with laboratory professionals who will be called upon to make technical and policy decisions, and clinical interpretations arising from questions (or problems) from many sources. Questions can range from personal queries arising in daily routine practice through to dealing with major management and policy issues. Whilst experience plays an important part in decision making, there is an increasing emphasis on, and accountability for, decisions being informed by a strong evidence base.

Formulation of the right question is the first step in the Evidence-Based Laboratory Medicine (EBLM) Cycle (Figure 1),² which is comprised of a series of steps that can be followed in evidence-based decision making. Some examples of questions for screening, diagnosis, prognosis, treatment, operational and economic situations are provided in Table 1, and a broader discussion of the topic can be found in an earlier paper.³ The second step is acquiring evidence through primary research or review of the literature, which is used to inform practice, in commissioning of services and in performance management and quality improvement of services.^4,5

Figure 1.

The core of the EBLM cycle. Adapted from Reference 1 with permission.

Table 1.

Examples of questions that might prompt a search of the literature to find the required evidence.

Type of question	Typical (unstructured) question
Screening	Can HbA_1c be used to screen for type 2 diabetes?
Diagnosis	Is serum cystatin C a better test than serum creatinine for the diagnosis of renal failure?
Prognosis	Is a troponin test helpful in risk stratification of patients with acute coronary syndrome?
Treatment	Does regular measurement of natriuretic peptide help to guide treatment in patients with heart failure?
Operational	Will point of care testing for HbA_1c improve health outcomes in the management of diabetes?
Economic	Will point of care testing for troponin improve the efficiency of the Emergency Department in managing patients presenting with chest pain?

The approach to searching for the evidence will depend on the question being asked and the purpose of the search. In some circumstances, time is of the essence, for example when responding to a question asked during a patient consultation, and a ‘quick and dirty’ or ‘quick and clean’ look at the literature will give the searcher the desired information. This approach is often sufficient if the clinician or laboratory professional needs to verify information or acquire a general overview of the topic. At other times, a more comprehensive and systematic search is required, for example when planning a research study, preparing a systematic review, developing a guideline or initiating large-scale service improvements.

The primary aim of this article was to provide insight into conducting quick searches efficiently and effectively. We will also point out resources that will facilitate more comprehensive, systematic reviews of diagnostic tests and new technologies. We have chosen to use a point of care testing scenario and maintain this throughout the discussion; however, the guidance is equally applicable to individual tests and other technologies.

Question formulation

When information is needed quickly, it is tempting to dive straight in and start searching. However, a more thoughtful and organised approach, in which time is spent considering the question, will pay dividends. As Francis Bacon once said, ‘a prudent question is one half of wisdom’; difficulties in searching are often encountered in the absence of a clearly thought out question. Therefore, successful searching is predicated on formulation of an answerable question³ because a clear question underpins the development of a search strategy. It can be helpful to adopt the approach identified in the early years of developing the principles of evidence-based medicine, using the PICO acronym.⁶ Over time, the original acronym has been adapted to include variations that are suited to different questions (Table 2), including intervention and diagnosis (PICOS, PICOT, PIRT), epidemiology (PECO), health management (ECLIPSE⁷) or qualitative (SPICE, SPIDER^8,9) enquiries. Irrespective of the chosen acronym, it can often be useful to ask the following questions in relation to the topic of interest:

What is the Patient/population group?

What is the Intervention/exposure/index test of interest?

Is there a Control/comparator/reference standard?

What is the Outcome?

What is the Setting?

Table 2.

A summary of frameworks employed for helping with question formulation.

Framework	Elements of framework	Application
PICO	Population, intervention, comparison, outcome	Intervention
PICO	Population, intervention, comparison, outcome	Diagnosis
PECO	Population, exposure, comparison, outcome	Epidemiology
PICOT	Population, intervention, comparison, outcome, time	Intervention
PICOT	Population, intervention, comparison, outcome, time	Diagnosis
PICOT	Population, intervention, comparison, outcome, type of study	Intervention
PICOT		Diagnosis
PICOS	Population, intervention, comparison, outcome, setting	Intervention
PICOS	Population, intervention, comparison, outcome, setting	Diagnosis
PIRT	Population, index test, reference standard, target condition	Diagnosis
SPICE	Setting, perspective, intervention, comparison, evaluation	Qualitative
SPIDER	Sample, phenomenon of interest, design, evaluation, research type	Qualitative
ECLIPSE	Expectation, client group, location, impact, professionals, service	Health management

This approach is fundamental for bringing the question into focus, but can also be the springboard for developing the search terms and phrases. An illustration is provided on preparing a structured search strategy in Table 3, as a clinical scenario is broken down into its key concepts and search terms.

Table 3.

Preparing a structured question to guide the search: in diabetic patients presenting to their general practitioner, does a point of care meter to measure blood ketones improve the diagnosis of diabetic ketoacidosis?

Element of question	Subject of question	Alternatives
P =	Diabetic patient	Diabetes
P =	Diabetic patient	Diabetic
I=	Point of care ketone test	Point of care ketone
		Near patient ketone
		Bedside ketone
		Capillary ketone
		Precision Xtra meter
C=	Not applicable	Not applicable
O=	Diagnosis of ketoacidosis	Ketoacidosis
S=	General practitioner	General practitioner
		Primary Care
		General practice
		Family practice
		Family physicians

Search techniques

There are a few key points to remember about electronic searching, whether the resource utilised is a web-search engine, an evidence-based ‘point of care’ information tool or a bibliographic database. In order to use resources effectively and efficiently, it is important that searchers become familiar with the search language and techniques used on each individual resource by looking at the help facility, viewing tutorials or consulting local librarians. The following search techniques are frequently common but cannot be applied across all resources (see Figure 2).

Figure 2.

Example of a quick search and structured search strategy

Synonyms

To capture relevant research, searchers need to think about synonyms and variant spellings for their search concepts, to account for the different language used by authors. For example, different terminology is used to describe point of care testing – near patient, bedside, POC, POCT, etc. Some resources have an automatic synonym facility, and in other resources you will need to type in each different search term. Although you may identify search terms and synonyms for all the concepts in the clinical question, these are not always applied in the search. It is often more efficient, particularly with a quick search to rely on searching for the key concepts, in this example, diabetes ‘near patient testing’ ketoacidosis. The results can then be browsed to identify those focusing on diagnosis. If the electronic resource has a thesaurus search, this can be used to identify appropriate search terms.

Boolean logic

In order to develop a focused search strategy, keywords need to be searched in combination rather than in isolation. Boolean logic¹⁰ is used to broaden and focus a search:

OR = to broaden out the search, to include synonyms and variant spellings, e.g. ‘point of care test’ OR ‘near patient test’ OR ‘bedside test’.

AND = to narrow the search down, to combine different search concepts, e.g. diabetes AND ‘point of care test’.

NOT = to exclude concepts, e.g. diagnosis NOT monitoring.

Grouping search terms

To make the most of Boolean logic, use parentheses to group terms together, and this allows you to use both AND/OR in the search query for a maximised search, e.g. (‘point of care test’ OR ‘near patient test’ OR ‘bedside test’) AND (diabetes OR diabetic).

Truncation and wild cards

Use a truncation symbol (often an *, but could be a $ or ?) to find words that have the same beginning but might have different endings, e.g. test* for test, tests, testing, etc. These symbols can occasionally be used as wildcards within words to replace 0–1 letters where there might be an alternative spelling, e.g. gyn?ecology for gynaecology or gynecology.

Phrase searching

In the case of some web-sites and databases, an implied AND is used to automatically combine search words. To override this and search for phrases, enclose terms in double quote marks, e.g. ‘point of care test’.

Limits

Bibliographic databases have long used limits, for example, language, publication year, age range and publication type to focus searches. These are often also available on web-search engines and ‘point of care’ information tools and can be applied post hoc to reduce the number of references or records retrieved. The publication type limits can be particularly useful at the start of a search process to identify secondary resources (reviews or guidelines) that will give an overview of a topic.

Methodological search filters (‘Hedges’)

Validated search filters have been developed to allow searchers to narrow down subject searches by type of research and are often used for post hoc categorisation of search results. The original work was done to aid the production of systematic reviews by developing a string of reliable search terms for identifying randomised controlled trials. Subsequently, a similar approach was applied to identify studies for other types of questions, for example on PubMed Clinical Queries, ‘diagnosis’, ‘etiology’, ‘prognosis’ and ‘clinical prediction’ guide filters are available. In recent years, filters have also been developed for age groups, disease areas and geographic locations. The InterTasc web-site brings together information on the application and development of search filters.¹¹

Technological advancement has allowed improved linking between individual articles or sources of information. Algorithm-derived related article links on PubMed and Google Scholar, along with topic links within ‘point of care’ information tools allow searchers to find information serendipitously through relationships with the original source. This can be a time-saving technique in a quick search, but also an adjunct to a comprehensive search where reassurance is needed that no key research has been missed.

Thesaurus (MeSH) searching

Traditional bibliographic databases have a thesaurus facility that allows more focused subject searching. The Medical Subject Heading [MeSH] search on PubMed is an example of this and can be used by the searcher to conduct an exhaustive but precise search.

Quick searching

Once the question has been decided upon, the next stage is to choose resources or bibliographic databases for searching. A search as part of an exhaustive research gathering exercise, for example a systematic review, will involve searching a large number of sources for both published and unpublished literature. The key to an efficient and effective quick search is the application of search techniques on one or two appropriate resources. A good start for a quick search is to concentrate on identifying sources of secondary evidence on the topic of interest, from synthesised topic reviews to systematic reviews, guidelines and evidence syntheses.

Topic reviews – point of care information tools

In recent years, there has been increasing development of subscription-based ‘point of care’ information tools or e-textbooks (Table 4). These have been developed to present synthesised evidence to enable clinicians to make decisions quickly during patient encounters. However, they can also be useful for laboratory professionals to identify background or synthesised information quickly. A recent evaluation of some of these tools found that clinicians were satisfied with the time taken and quality of information, but there was not a significant preference between clinicians for one particular resource.¹² These resources share common characteristics, and they often have a simple search box and display results in a way that is easy to browse enabling the clinician to drill down to relevant information. This is often done by presenting information according to the patient journey from initial presentation through diagnosis to therapy and monitoring/after care. As a result, a search approach that identifies the patient problem first, either symptom or condition, then drills down to the section on diagnostic tests is likely to be more effective than searching outright for a diagnostic test. In the absence of access to a subscription-based ‘point of care’ information tool, there are health-specific search engines that provide links to synthesised evidence and key papers.

Table 4.

Examples of subscription-based point of care information resources.

Information resource	Web address
Best Practice	http://bestpractice.bmj.com/best-practice/welcome.html
Clinical Key	https://www.clinicalkey.com
DynaMed	https://dynamed.ebscohost.com
First Consult	http://www.mdconsult.com/das/pdxmd/lookup/390204265-916?type = med
UpToDate	http://www.uptodate.com/contents/search

Finding systematic reviews, guidelines and evidence syntheses – health specific search engines

TRIPdatabase (http://www.tripdatabase.com) was established to allow busy health professionals to find evidence-based information quickly. It has a single search box, plus an option for an advanced search or PICO search if the initial search yields too many or too few results. TRIP searches a range of resources and the retrieved results are categorised according to type of information from secondary evidence through to key primary research, e-textbooks and patient information. In return for typing the following search – diabetes (bedside OR ‘point of care’ OR ‘near patient’) ketoacidosis – 105 results were returned, with 39 categorised as secondary evidence, either evidence-based synopses, systematic reviews or guidelines (Figure 3). The categorisation allows the searcher to scan the literature quickly and to go straight to the type of information that is most likely to answer the question.

Figure 3.

Example search on TRIPdatabase, accessed 21 November 2013.

NICE Evidence Search (http://www.evidence.nhs.uk) is maintained by the National Institute for Health and Care Excellence to provide access to authoritative evidence in clinical, non-clinical and social care settings. The previous search was applied and the results sorted by relevance with 10 references per page. However, again NICE Evidence Search categorises the evidence by area of interest, type of evidence, clinical queries, sources, medicines and devices and publication date. A two-pronged approach is often useful when using NICE Evidence Search, viewing the first two pages of results ranked by relevance but also viewing results in the most appropriate category for the question, for example clinical queries – diagnosis or areas of interest – drugs and technologies.

SUMSearch (http://sumsearch.org/) is a meta-search engine developed at the University of Kansas that allows the searcher to interrogate several evidence-based resources at the same time; these include, Medline, Database of Abstracts of Reviews of Effects and National Guidelines Clearinghouse. There is a simple search box for the key terms, with a variety of ‘tick box’ categories that focus the search by study type, age range and publication year.

PubMed Clinical Queries (http://www.pubmed.gov) is a filtered search facility within this well-known resource allowing free access to the Medline database. A basic search can be run; in order to focus the search, pre-filtered clinical queries can be applied to reflect the type of information sought – systematic reviews, diagnosis, etiology, therapy, prognosis or clinical prediction guides. These filters have been developed and validated by the Health Information Management Unit at McMaster University (http://hiru.mcmaster.ca/hiru/hedges/indexHIRU.htm), allowing the searcher to apply a broad or narrow filter depending on whether sensitivity or specificity is the prime motivator.

The aforementioned sites search multiple resources concurrently, including websites and databases of systematic reviews, guidelines and evidence syntheses. However, it is also possible to search these resources directly.

MedionDatabase (http://www.mediondatabase.nl/) is the main resource for reviews of diagnostic accuracy. In addition, they can be identified through Cochrane Collaboration (http://www.cochrane.org/cochrane-reviews) and Database of Abstracts of Reviews of Effects (http://www.york.ac.uk/inst/crd/index_databases.htm) which provides appraisals of systematic reviews.

There are numerous guideline websites, these include National Guidelines Clearinghouse (http://www.guidelines.gov), NICE (http://www.nice.org.uk) and SIGN (Scottish Intercollegiate Guidelines Network, http://www.sign.ac.uk). In addition, for upcoming technologies, it is worth keeping abreast of the evidence reports of horizon scanning centres, including MaDOx (http://madox.org), National Horizon Scanning Centre (http://hsc.nihr.ac.uk) and Australia and New Zealand Horizon Scanning Network (http://www.horizon scanning.gov.au).

In the absence of appropriate good quality secondary evidence relating to the clinical question, a search for primary research through bibliographic databases or web-search engines may be necessary.

Bibliographic databases

Bibliographic databases contain references to published research, most commonly journal articles, but also conference proceedings, books and theses.

PubMed (http://www.pubmed.gov) is the largest freely available database in health and medicine. PubMed includes the Medline database, but also contains additional material including ‘electronic ahead of print’ publications.¹³

A range of subscription databases may be available through a local institutional library. In health care, these may include:

Medline (http://www.nlm.nih.gov/bsd/pmresources.html) focusses on health and medicine;

CINAHL (Cumulative Index to Nursing and Allied Health Literature, http://www.ebscohost.com/biomedical-libraries/the-cinahl-database) focuses on research in the nursing and allied health field. It also contains non-journal material including dissertations;

Embase (http://www.elsevier.com/online-tools/embase) focusses on health and medicine and has a greater European emphasis, with subject strengths in psychiatry and pharmacology, and contains up to the minute research. It also contains non-journal material including conference abstracts;

PsycINFO (http://www.ebscohost.com/academic/psycinfo) is the foremost source for research on psychology and mental health. It also contains non-journal material including dissertations;

Scopus (http://www.elsevier.com/online-tools/scopus) is a multidisciplinary database containing abstracts and citations for peer-reviewed journals in the scientific, technical, medical, and social sciences (including arts and humanities).

These bibliographic databases overlap in terms of content, but do also contain unique material, and so it is often necessary to search multiple databases. Bibliographic databases benefit from sophisticated search interfaces and the ability to apply a range of techniques to maximise the effectiveness and efficiency of the search. As a result, it is advisable to familiarise oneself with individual databases through the help facility, viewing online tutorials or consulting local librarians.

Web search engines

Google (http://www.google.com) is often the first point of call for answering quick questions¹⁴; as such, it would be difficult to end a section on searching without considering the powerful search capability of Google, Google Scholar (http://scholar.google.com) and other general web search engines. Several studies have been published comparing Google and/or Google Scholar with established bibliographic databases and newer ‘point of care’ information tools.^15–18 There is no definitive view on whether the Google products are better or worse than other resources, but the studies have outlined some benefits and drawbacks. The Google products have a familiarity that makes them easy to use and the relevancy algorithm brings useful information to the fore; however, these advantages confer disadvantages. The simplicity of the search function makes it difficult to focus a search and thus it lacks precision, and the relevancy algorithm often means that recent research is further down the list of displayed results. In addition, a greater emphasis will need to be applied to appraisal of retrieved results as they will include both peer reviewed and non-peer reviewed material. The latter may include useful information, e.g. white papers from in vitro diagnostic companies and commercial intelligence white papers. The message for web search engines, as with any of the resources mentioned above, is that they should not be used in isolation, but that they should be part of a suite of resources that are used for searching.

Searching apps

The increasing use and availability of smartphones and tablet computers have created a demand for information resources that are accessible through mobile devices. There are apps or mobile versions available for many of the resources mentioned above, including PubMed (http://www.pubmed.gov), NICE guidance (http://www.nice.org.uk) and UpToDate (http://www.uptodate.com). To find and download the mobile versions, the reader is advised to look at the resource website or the app store for the particular mobile device in question.

Systematic review searching

The approach to searching for studies for inclusion in a systematic review of diagnostic test accuracy includes the development of a structured search strategy based on a well-built clinical question and the application of that strategy across multiple databases. The searcher would also employ additional ‘snowballing’ techniques to identify published and unpublished studies through browsing trial registers, reading reference lists, performing forward citation searches and hand-searching. The difficulties of conducting diagnostic systematic reviews have been extensively studied;^19–24 however, methodological guidance has been laid down through work at the Cochrane Collaboration²⁵ and Agency for Healthcare Research and Quality.²⁶ It is now common practice to conduct systematic reviews as part of the research process, as a precursor to setting up a trial or part of a PhD submission. In addition, it is often included in the guideline preparation or service improvement process. These guidelines should be considered carefully by anyone starting a search for studies for inclusion in a systematic review.

Conclusions

Laboratory professionals are faced with a range of questions on a daily basis, mostly routine, where the answers are based on experience or laboratory protocols. However, as the field of laboratory medicine expands, and the role of the laboratory professional as a member of the clinical team is more broadly recognised, the need to respond to questions will increase. The search techniques and resources outlined above provide an introduction for those professionals who need to search the literature for further evidence to support decision making, relating to individual patients or general service improvement.

Since Sackett and Strauss first talked about applying evidence during the process of ward rounds,²⁷ there has been an increasing recognition that searching for evidence has become part of routine clinical practice, rather than simply a research activity.^28–31 The laboratory medicine service is a knowledge-based service and thus the ability to search for evidence is an important skill for the laboratory medicine professional to employ – at any time, and in any sphere of his/her work.

Footnotes

Acknowledgements

This article was prepared at the invitation of the Clinical Sciences Reviews Committee of the Association for Clinical Biochemistry. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.

References

Price

Lozar Glenn

Christenson

. Applying evidence-based laboratory medicine: a step-by-step guide, Washington, DC: American Association for Clinical Chemistry, 2009.

Price

. Evidence-based laboratory medicine: supporting decision-making. Clin Chem 2000; 46: 1041–1050.

Price

Christenson

. Ask the right question: a critical step for practicing evidence-based laboratory medicine. Ann Clin Biochem 2013; 50: 306–314.

Christenson

. Committee on evidence based laboratory medicine of the international federation for clinical chemistry laboratory, evidence-based laboratory medicine – a guide for critical evaluation of in vitro laboratory testing. Ann Clin Biochem 2007; 44: 111–130.

Price

. Evidence-based laboratory medicine: is it working in practice? Clin Biochem Rev 2012; 33: 13–19.

Richardson

Wilson

Nishikawa

. The well-built clinical question: a key to evidence-based decisions. ACP J Club 1995; 123: A12– A13.

Wildridge

Bell

. How CLIP became ECLIPSE: a mnemonic to assist in searching for health policy/management information. Health Info Libr J 2002; 19: 113–115.

Booth

. Clear and present questions: formulating questions for evidence based practice. Library Hi Tech 2006; 24: 355–368.

Cooke

Smith

Booth

. Beyond PICO: the SPIDER tool for qualitative evidence synthesis. Qual Health Res 2012; 22: 1435–1443.

10.

Higgins JPT and Green S (eds). Boolean operators (AND, OR, NOT). Chapter 6: searching for studies, Section 6.4.7. In: Cochrane handbook for systematic reviews of interventions version 5.1.0. The Cochrane Collaboration, www.cochrane-handbook.org (2011, accessed 27 October 2013).

11.

The University of York Centre for Reviews and Dissemination. The InterTASC information specialists’ sub-group search filter resource, http://www.york.ac.uk/inst/crd/intertasc/ (accessed 17 May 2013).

12.

Goodyear-Smith

Kerse

Warren

. Evaluation of e-textbooks. DynaMed, MD Consult and UpToDate. Aust Fam Physician 2008; 37: 878–882.

13.

MEDLINE, PubMed, and PMC (PubMed Central): How are they different? U.S. national Library of Medicine, http://www.nlm.nih.gov/pubs/factsheets/dif_ med_pub.html (accessed 22 October 2013).

14.

Giustini

. How Google is changing medicine. BMJ 2005; 331: 1487–1488.

15.

Nourbakhsh

Nugent

Wang

. Medical literature searches: a comparison of PubMed and Google Scholar. Health Info Libr J 2012; 29: 214–222.

16.

Thiele

Poiro

Scalzo

. Speed, accuracy, and confidence in Google, Ovid, PubMed, and UpToDate: results of a randomised trial. Postgrad Med J 2010; 86: 459–465.

17.

Shultz

. Comparing test searches in PubMed and Google Scholar. J Med Libr Assoc 2007; 95: 442–445.

18.

Falagas

Pitsouni

Malietzis

. Comparison of PubMed, Scopus, Web of Science, and Google Scholar: strengths and weaknesses. FASEB J 2008; 22: 338–342.

19.

Leeflang

Scholten

Rutjes

. Use of methodological search filters to identify diagnostic accuracy studies can lead to the omission of relevant studies. J Clin Epidemiol 2006; 59: 234–240.

20.

Doust

Pietrzak

Sanders

. Identifying studies for systematic reviews of diagnostic tests was difficult due to the poor sensitivity and precision of methodologic filters and the lack of information in the abstract. J Clin Epidemiol 2005; 58: 444–449.

21.

Whiting

Westwood

Burke

. Systematic reviews of test accuracy should search a range of databases to identify primary studies. J Clin Epidemiol 2008; 61: 357–364.

22.

Kastner

Wilczynski

McKibbon

. Diagnostic test systematic reviews: bibliographic search filters (“Clinical Queries”) for diagnostic accuracy studies perform well. J Clin Epidemiol 2009; 62: 974–981.

23.

Ritchie

Glanville

Lefebvre

. Do published search filters to identify diagnostic test accuracy studies perform adequately? Health Info Libr J 2007; 24: 188–192.

24.

Whiting

Westwood

Beynon

. Inclusion of methodological filters in searches for diagnostic test accuracy studies misses relevant studies. J Clin Epidemiol 2011; 64: 602–607.

25.

de Vet HCW, Eisinga A, Riphagen II, et al. Chapter 7: searching for studies. In: Cochrane handbook for systematic reviews of diagnostic test accuracy. Version 0.4. The Cochrane Collaboration, http://srdta.cochrane.org/sites/srdta.cochrane.org/files/uploads/Chapter07-Searching-(September-2008).pdf (2008, accessed 27 October 2103).

26.

Relevo

. Chapter 4: effective search strategies for systematic reviews of medical tests. J Gen Intern Med 2012; 27: S28–S32.

27.

Sackett

Straus

. Finding and applying evidence during clinical rounds: the “evidence cart”. JAMA 1998; 280: 1336–1338.

28.

Magrabi

Coiera

Westbrook

. General practitioners' use of online evidence during consultations. J Med Inform 2005; 74: 1–12.

29.

Van Duppen

Aertgeerts

Hannes

. Online on-the‐spot searching increases use of evidence during consultations in family practice. Patient Educ Couns 2007; 68: 61–65.

30.

León

Fontelo

Green

. Evidence-based medicine among internal medicine residents in a community hospital program using smart phones. BMC Med Inform Decis Mak 2007; 7: 5–5.

31.

Phua

See

Khalizah

. Utility of the electronic information resource UpToDate for clinical decision-making at bedside rounds. Singapore Med J 2012; 53: 116–120.

Searching for evidence: a guide to finding the evidence in laboratory medicine

Abstract

Keywords

Introduction

Question formulation

Search techniques

Synonyms

Boolean logic

Grouping search terms

Truncation and wild cards

Phrase searching

Limits

Methodological search filters (‘Hedges’)

Related articles

Thesaurus (MeSH) searching

Quick searching

Topic reviews – point of care information tools

Finding systematic reviews, guidelines and evidence syntheses – health specific search engines

Bibliographic databases

Web search engines

Searching apps

Systematic review searching

Conclusions

Footnotes

Acknowledgements

References