Cochrane training guide revised july 2010


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Cochrane training guide revised july 2010

  1. 1. The Cochrane Library A Training GuideRon HudsonOutreach Training LibrarianCroydon Health Library and Resources ServiceNHS Croydon12-18 Lennard RoadCroydon CR9 2RSTel: 020 8274 6316Mob: 07733 300 104Email: ron.hudson@croydonpct.nhs.ukJuly 2010With thanks to Mary Last, Clinical Support Librarian, Bloomsbury Healthcare Library
  2. 2. Contents1. Overview - sources of research-based evidence Sources of research-based evidence ............................................................. 3 The hierarchy of evidence ............................................................................... 42. Introduction to the Cochrane Library What is the Cochrane Library? ........................................................................ 5 When to use the Cochrane Library.................................................................. 5 Background and history of the Cochrane Library ............................................ 6 The databases ................................................................................................ 7 Definitions ……………………………………………………………………………93. Getting started Accessing the Cochrane Library.................................................................... 10 Site registration and password ..................................................................... 10 Explaining the home page ............................................................................ 124. Browsing the Cochrane Library Browsing the main databases ...................................................................... 13 Cochrane Database of Systematic Reviews Symbols ..……………………….14 Browsing the Cochrane Database of Systematic Reviews ............................ 15 Browsing by Topic.................................................................................... 15 Browsing by Review Group ..................................................................... 155. Searching the Cochrane Library Search tips and tricks ................................................................................... 17 Simple search ............................................................................................... 19 Advanced search .......................................................................................... 20 Search history .............................................................................................. 22 Searching MeSH .......................................................................................... 246. Viewing, printing and saving search results Viewing search results .................................................................................. 27 Different sections of a Cochrane Systematic Review ……………………29 Following up on primary references………………………………………….30 Interpreting graphs ................................................................................... 30 Saving and printing search results ................................................................ 31 Saving a search............................................................................................. 32 Saving a search strategy ............................................................................... 33 Setting alerts ................................................................................................ 35 2
  3. 3. Overview - sources of research-based evidenceEvidence-based practice has been described as: … the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients. The practice of evidence based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research. Sackett DL et al. BMJ, 1996, Vol 312, pp 71-72The range of the ‘external clinical evidence’ available to health care professionals isoften described as a hierarchy and this is shown on the following page, from individualopinion at the bottom of the pyramid, through research methodologies of varying rigour.You can access most of this enormous quantity of research-based evidence through theprimary journal literature by searching databases search as Medline.There are, however, specialist resources that you can go to which evaluate andsummarise available research evidence when you want to know about the effectivenessof a particular health care intervention. These can be divided into:• Reviews eg Cochrane Database of Systematic Reviews Reviews are examples of secondary research. Standard reviews compare the results of two or more primary studies. The systematic review, however, aims to give a full picture of a topic by identifying all available evidence, appraising it and then presenting a cumulative summary. This usually includes a meta-analysis, the combination of results from primary studies into a single statistical result. More information about systematic reviews can be found on page 9.• Digests eg Clinical Evidence Digests identify the major evidence on particular topics and provide key messages.• Guidelines eg NeLH Guidelines Finder Guidelines provide recommendations for effective practice based on current evidence.If you find a systematic review or summary of current evidence which answers yourquestion you will be saved the work of searching databases for journal literature as wellas much of the reading and critical appraisal involved. 3
  4. 4. The Hierarchy of Evidence BESTA systematic review of at least two randomized controlled trialsA randomized, controlled trialA cohort studyA case-control studyAn uncontrolled study with dramatic resultsAn expert committee report or similarAnecdotal evidence WORSTHarrison S. (ed) Evidence-based medicine: its relevance and application to primary carecommissioning. London: Royal Society of Medicine Press Ltd, 1998. 4
  5. 5. Introduction to the Cochrane LibraryWhat is the Cochrane Library?The Cochrane Library is described as the best single source of reliable information onthe effects of interventions in health care. It is designed to provide information andevidence to support decisions taken in health care and to inform those receiving care.The Cochrane Library is a collection of databases containing systematic reviews, healthtechnology assessments, economic evaluations and controlled trials. More informationabout each database can be found on page 7. Some databases provide full-text articles,some just bibliographic details with abstracts.When to use the Cochrane LibraryThe whole of the Cochrane Library is concerned with the effectiveness of interventionsfor a given health care problem or in a particular health care situation.The Cochrane Library is useful for answering the following types of queries: • What is the effectiveness of treatment X in condition Y? What is the effectiveness of aspirin in vascular dementia? • Is treatment A better than treatment B? Is there any evidence that clozapine is more effective in the treatment of schizophrenia than standard antipsychotics? • What is an effective intervention to achieve outcome Z? What are the most effective strategies for stopping smoking?The Cochrane Library is not useful for these types of questions: • General health care information Are there any new drugs for manic depression? • Statistical information What is the teenage pregnancy rate? • Cause, prognosis, epidemiology or risk factors for an illness What are the health effects of unemployment? • Guidelines • Current research (apart from systematic reviews and randomised controlled trials) 5
  6. 6. Background and history of the Cochrane LibrarySince 1996, systematic reviews prepared and maintained by the Cochrane Collaborationhave been published in The Cochrane Library, along with bibliographic and quality-assessed material on the effects of health care interventions submitted by others.Cochrane reviews are a highly regarded source of evidence about the effects of healthcare interventions and widely thought of as being of better quality, on average, than theircounterparts in print journals.The first issue of the Cochrane Library in 1996 therefore incorporated:• Regularly-updated systematic reviews and protocols for reviews in preparation• Quality appraisals of reviews published elsewhere• A register of controlled trialsThese collections were viewed as part of a hierarchy of evidence, ranging from regularlyupdated reviews, to high-quality reviews published elsewhere, to reports of individualcontrolled trials.There are now six main databases plus one other giving information about the CochraneCollaboration and its Review Groups. Further information on each of the maindatabases can be found below.Further informationThe Cochrane Collaborations web site - - is a useful source ofinformation. The Newcomers Guide on it provides background information on theCochrane Collaboration and its systematic reviews.An article about the genesis and history of the Cochrane Library between 1988 and 2003can be found at 6
  7. 7. The DatabasesCochrane Database of Systematic Reviews (CDSR; Cochrane Reviews)A systematic review identifies an intervention for a specific disease or other problem inhealth care, and determines whether or not this intervention works. To do this authorslocate, appraise and synthesise evidence from as many relevant scientific studies aspossible. They summarise conclusions about effectiveness, and provide a uniquecollation of the known evidence on a given topic, so that others can easily review theprimary studies for any intervention.As of Issue 4, 2008, this database also includes systematic reviews of diagnostic testaccuracy. Cochrane diagnostic test accuracy reviews are not based on randomizedcontrolled trials, but mainly on cross sectional studies.From Issue 2, 2007, this database also includes the methodology reviews that werepreviously part of Cochrane Database of Methodology Reviews (CDMR; MethodsReviews)Cochrane Methodology Reviews are full-text systematic reviews of methodologicalstudies. Highly structured and systematic, evidence from methodological research isincluded or excluded on the basis of explicit quality criteria, thus minimising bias. Eachreview covers a specific and well-defined area of methodology. Data from studies areoften combined statistically to increase the power of the findings of numerous studies,which on their own may be too small to produce reliable results. In such cases, thereview may also include graphs presenting the data from each individual study.Protocols provide information about reviews which are currently being written. Theysummarise the background and the rationale of the review.Database of Abstracts of Reviews of Effects (DARE; Other Reviews)DARE includes structured abstracts of systematic reviews from around the world whichhave been evaluated by the reviewers at the NHS Centre for Reviews and Dissemination(NHS CRD) at the University of York. Only reviews that meet minimum quality criteriaare included in DARE. These reviews cover topics that have yet to be addressed by aCochrane review.Cochrane Central Register of Controlled Trials (CENTRAL; Clinical Trials)CENTRAL includes details of published articles taken from bibliographic databases(notably Medline and Embase), and other published and unpublished sources.CENTRAL records include the title of the article, information on where it was published(bibliographic details) and, in many cases, a summary of the article. They do not containthe full text of the article.Trials are identified from multiple sources, including searches of bibliographic databases,hand searches of many hundreds of journals and conference proceedings, and searchesof other trial registers. 7
  8. 8. Cochrane Methodology Register (CMR; Methods Studies)This is a bibliography of publications which report on methods used in the conduct ofcontrolled trials. It includes journal articles, books, and conference proceedings. Thesearticles are taken from the Medline database and from hand searches. The databasecontains studies of methods used in reviews and in more general methodological studieswhich could be relevant to anyone preparing a systematic review. CMR does not containthe full text of articles.Health Technology Assessment Database (HTA; Technology Assessments)This database contains information on healthcare technology assessments (defined asprevention and rehabilitation, vaccines, pharmaceuticals and devices, medical andsurgical procedures and the systems within which health is protected and maintained).The database contains details of ongoing projects and completed publications fromhealth technology assessment organisations. HTA records follow a standard structure.Some records contain the title of the project, with the name of the centre responsible andan indication of where further details can be obtained. Other records contain publicationdetails, with structured abstracts where available. Records do not, in either case, containthe full text of the report.NHS Economic Evaluation Database (NHS EED; Economic Evaluations)This database contains structured abstracts of articles describing economic evaluationsof health care interventions. The articles are identified by searching through key medicaljournals, bibliographic databases and less widely available literature. A paper will beincluded if it provides a comparison of treatments and examines both the costs andoutcomes of the alternatives. The database also includes bibliographic details of articlesexamining relevant topics, (for example the burden of illness, economic methodologypapers, and reviews of economic evaluations), and short abstracts of studies originallyincluded in the Department of Health Register of Cost-Effective Studies. Records do notcontain the full text of the original article. 8
  9. 9. DefinitionsSystematic Review:Systematic reviews differ from other types of review in that they adhere to a strict designin order to make them more comprehensive, thus minimising the chance of bias, andensuring their reliability. Rather than reflecting the views of the authors, or being basedon a partial selection of the literature, (as is the case with many articles and reviews thatare not explicitly systematic), they contain all known references to trials on a particularintervention and a comprehensive summary of the available evidence. The reviews aretherefore also valuable sources of information for those receiving care, as well as fordecision makers and researchers.Economic Evaluation:Full economic evaluations, as defined by the NHS CRD, can be one of the following:• a cost-benefit analysis (CBA), which measures both costs and benefits in monetary values and calculates net monetary gains or losses (presented as a cost-benefit ratio);• a cost-effectiveness analysis (CEA), which compares interventions with a common outcome (such as blood pressure level) to discover which produces the maximum outcome for the same input of resources in a given population;• a cost-utility analysis (CUA), which measures the benefits of alternative treatments or types of care by using clearly defined utility measures (such as quality-adjusted life years) 9
  10. 10. Getting started Accessing the Cochrane Library You can either go directly to the Cochrane Library at or from the following link: • National Library for Health (under Evidence Based Reviews) – The databases are updated monthly. Also on the National Library for Health site under Evidence Based Reviews you will find links to DARE and NHS EED which represent the most up to date versions of these databases. They can be searched individually. Site registration and password You do not need a password to access the Cochrane Library or to conduct one-off searches, view full records or to print or to save them, but if you are likely to be a regular visitor to Cochrane and would like to be able to save searches and search strategies and to set up email alerts, you should register yourself on the Wiley InterScience site. NB You cannot use your Athens username and password to log on to the site. 1 2 1. Click ACCESS in the right centre of the screen 2. Click Register for Wiley Interscience • Fill in the registration form Your email address and the password you choose will be used as your username and password for the future. Try to register using your work email address and to avoid an email address ending in .com. You must also check the box to indicate that you have read the Terms of Usage. The information you enter will not be used by a third party. 10
  11. 11. • Click Submit Registration You will receive an email confirming receipt of your completed registration form. You must validate your account by clicking on the link in the message within 24 hours otherwise you may have to register all over again. To get back to the Cochrane Library: 3. Type Cochrane in the search box 4. Check the radio button Publication Titles 5. Click Go 6 43 5 • Then select the current issue of the Cochrane Library from the list of results You will now be back at the Cochrane Library home page. Logging on subsequently • The next time you access the Cochrane Library and click Log In you are taken to the main Wiley InterScience home page to enter your username and password. It is not recommended to check the box Remember Me if you share your computer with others. Once you have logged on you will still be on the Wiley page so will need to get back to the Cochrane Library in the way described above. Timing out You will find that after periods of inactivity during a search session you will be timed out and asked to re-enter your username and password. You will be taken back to where you were in your search and not lose anything. 6. Always remember to Log Out when you have finished a search session. 11
  12. 12. Explaining the home page Find out more about the Cochrane Collaboration Return to the home page Click here to log in if you have registered for aEnter your usernamesearch term Links enabling you to browse the resources on the Cochrane Library There are different ways of accessing the Cochrane Database of Systematic Reviews. You can view them: By Topic – Select a topic of interest and narrow it down New Reviews – Protocols and Reviews added to the database in the latest update Updated Reviews – Only those Reviews which have been recently updated A-Z – List of Reviews by title (warning, there are over 5,000 titles in alphabetical order) By Review Group – Reviews and Protocols by one of the 51 specific Review Groups e.g. Cochrane Drugs and Alcohol Group 12
  13. 13. Browsing the Cochrane Library Four of the six main databases can be browsed, alphabetically by title, by clicking on their name. Where necessary use the A-Z links and scroll bar to navigate the lists of titles presented. The exception is CENTRAL. Because it is so large it is not practical to browse. Choosing to browse this database will take you to an advanced search screen where you can restrict your search to CENTRAL alone. See page 20 for Advanced Searching. This is the A-Z browse screen for the Cochrane Database of Systematic Reviews: 21 1. The A-Z navigation tool 2. This allows various portions of the database to be displayed. The default will be all records but some of the databases will allow you to choose subsets of records. These options carry over to when you are viewing search results (see page 27). 13
  14. 14. Cochrane Database of Systematic Reviews SymbolsOn the Cochrane Database of Systematic Reviews you may also find the followingsymbols after records, which have been changed with Issue 2, 2008: A full review, complete with results and discussion, meta- analysis and an odds-ratio diagram This is an outline of a review in preparation, including background, rationale and methods A full-text systematic review of methodological studies A full-text systematic review of studies assessing accuracy of diagnostic tests A new review or protocol that has been published in the most recent quarter A new search for studies and content updated (no change to conclusions) A new search for studies and content updated (conclusions changed) There has been an important change to the conclusions of the review as published in the most recent quarter The protocol has been amended to reflect a change in scope as published in the most recent quarter The review or protocol has been withdrawn, which may be because it was considered to be out of date. Reasons for withdrawal are specified in the article The review includes comments. Readers can submit comments which are incorporated into the review together with answers and feedback from the review authors 14
  15. 15. Browsing the Cochrane Database of Systematic ReviewsThe Cochrane Database of Systematic Reviews can be browsed by topic, new orupdated reviews, A-Z or by Cochrane Review Group.Browsing by topicUse the drop-down list to browse review topics by your chosen Cochrane CollaborativeReview Group.Selecting a review group shows the broad topic areas which that group covers. Clickingon a heading opens out further sub-sections until you find a review of interest. Click Select your here to chosen Cochrane see a Collaborative complete Review Group reviewBrowsing by review groupThis brings up a list of the same review groups as searching by topic. But this time whenyou select the name of the review group you are interested in you are presented with acomplete list of reviews for that group. This are split into protocols and reviews,arranged alphabetically within each section. 15
  16. 16. Searching the Cochrane LibraryThere are four ways of searching the Cochrane Library:1. Simple search (see page 19) Using the single search box on the home page is fine if you want to do a very quick, one off search on a topic but you will not be able to build up a detailed or refined search strategy.2. Advanced search (see page 20) Advanced search allows you to enter several search concepts in up to five search boxes at one time. However we have found problems with this method and do not recommend it.3. Search history (see page 22) Conducting searches from within search history allows you to build up detailed search strategies by combining search statements together from a single screen. Any searches you perform, no matter which method of searching you have used, will be stored under search history for the duration of your current search session.4. MeSH search (see page 24) This is a specific method of searching using the index terms assigned to many of the records in the Cochrane Library. It is best used in conjunction with free text searching carried out within search history. 16
  17. 17. Search tips and tricksUnless you are searching using MeSH you will be entering your search terms in free-textformat. There are number of rules which will help you get the best out of the databases.Combining terms The Cochrane Library supports the use of AND and OR tousing AND or OR connect search concepts together, eg • postnatal and depression • cancer or neoplasm Hints: Just as when you use a search engine such as Google, typing in two or more words will automatically "AND" them together, so the AND can be omitted, eg • postnatal depression Similarly, OR can be replaced by a comma, eg • cancer, neoplasmPhrase searching If you want two words to be adjacent to each other the phrase must be enclosed in quotation marks, eg • "postnatal depression"Proximity connector Using the connector NEAR between words or phrases means that they will appear within 6 or 7 words of each other (excluding stop words), in any order, eg • postnatal near depression You can change how many words are between them, eg • postnatal near/3 depressionSpelling tips Most plurals are automatically searched for, eg • foot would also find feet If you dont want to find the plural, type in the singular form in quotation marks, eg • "foot" Common spelling variations are also automatically searched, eg • randomise or randomize 17
  18. 18. Wildcard/truncation The wildcard character is the asterisk *. It can be used at the beginning, end or in the middle of words. At the end of a word it acts as a truncation symbol to indicate other letters that might appear after a word stem, eg • diabet* would find diabetic or diabetes Hint: If you would only find the plural form of a word using truncation there is no need as plurals are found automatically (see above) At the beginning of a word, eg • *natal would find prenatal or antenatal or postnatal In the middle of the words to pick up variations, eg • hyp*tension would find both hypertension and hypotension Hint: Although common spelling variations should be found for you (see above), if you want to be sure that you have captured all possible spelling variants, use the wildcard character, eg • h*ematology would find haematology or hematology The wildcard character should also be used to replace potentially accented letters within words, eg • “m*ni*res disease” to find ménières diseasePunctuation Hyphens are treated as spaces, so hyphenated and unhyphenated forms of words will be searched for simultaneously • eg “body weight” will also find “body-weight’’ Other punctation, such as the apostrophe, are recognised, but can equally be left out, eg either St Johns wort or St Johns wort both work fine 18
  19. 19. Simple search 2 1You can therefore conduct simple searches using the above search tips in the singlesearch box on the Cochrane Library front page:1. Key in your search terms and click Go2. As a default the Title, Abstract and Keywords fields are searched, but you can alsoassign your search to other fields of the database, eg just the record title. For moreinformation about the various database fields see page 20. Hint If you use simple search for a search containing several search terms, including synonyms, be sure to use brackets around terms to ensure that the search you want runs smoothly. For example: • ("otitis media with effusion" or "glue ear") and antibiotic and child* It is vital to put brackets around the two synonymous terms to ensure that they are ORed together. With complex databases such as the Cochrane Library, AND commands will always run first within a search string, so without the brackets the search would in effect be: • "otitis media with effusion" or ("glue ear" and antibiotic and child*) 19
  20. 20. Advanced SearchAdvanced search allows you to enter several search concepts in up to five search boxesat one time. However there are problems with this method and using Search History isrecommended in preference (see page 22).• Click on Cochrane Advanced Search below the single search box on the home pageYou will see five interconnected search boxes and various options for restricting yoursearch.Database fieldsAll text Your term in any field of all the databases. For CDSR this will be the full text of the systematic review.Record title Article titles onlyAuthor Authors of articles onlyAbstract Abstracts onlyKeywords Your term in the Index field in all databases except "About" which don’t have an index field. All of the databases except CMR use MeSH as their index terms. CMR uses its own index terms called CMR words. CDSR, CENTRAL and NHS EED additionally use MeSH check words.Title, Abstract Your term in any of the fields, title, abstract or keyword.or Keywords 20
  21. 21. Tables Your term in the Table field. Tables only appear in the CDSR database.Publication type Searches the Publication field in CENTRAL only. The following possible terms used are: clinical trial; journal article; multicenter study; randomized controlled trial; controlled clinical trial.Source Searches the title field or the field which details the source of the original article referenced in the database.DOI A search for the DOI number in the DOA field of CDSR. (DOI means Digital Object Identifier see and limitsYou can also choose to:• Restrict your search to particular databases within the Cochrane Library• Select just new, updated, commented or withdrawn records (this applies to CDSR only)• Select a date range for your searchThere is little value in restricting your search to individual databases because searchresults are split by database allowing you to choose which set of results to look at.Rather, the structure of the database you are most interested in should dictate thesearch method you use.On the whole we would recommend not using Advanced Search. This is because of themisleading way in which terms are combined between the five search boxes. Just aswith the hint on using Simple Search on page 19 if you do use Advanced Search be sureto incorporate all synonyms within a single search box and not split them up. For example, do not construct a search statement such as: "otitis media with effusion" OR "glue ear" AND antibiotic AND child* Instead, you should construct it as: "otitis media with effusion" or "glue ear" AND antibiotic AND child* 21
  22. 22. Search historyClicking on Search History below the single search box on the home page takes you toa much simpler search page than Advanced Search with a single search box.The purpose of using Search History is to build up a search strategy consisting ofseveral search statements and then use commands to combine those individual termstogether. This forces you to think carefully about the construction of your searchstatement. It encourages you to search for one term, or concept, at a time, andadditionally allows you to combine free text searching with MeSH searching (see page24) to build up a thorough search strategy.In addition to your search term you can• Select just new, updated, commented or withdrawn records (this applies to CDSR only)• Restrict your search to a particular database• Select a date rangeSearching fieldsYou can now include field “labels” as part of your search statement to find theoccurrence of words or phrases in particular fields such as the title or author. Availablefield labels are:Field Name Label Abstract :ab Author :au Keywords :kw Source :so Title :ti Publication Type :pt Tables :tb DOI :doi If no field tag is specified, “All text” issearched as the default 22
  23. 23. The following chart gives specific examples of how field labels can be used within asearch.Options Example Action Diabetes Searches diabetes in ALL text fieldsNo field tag (current default)One field tag Diabetes:ti Searches diabetes in title field Diabetes:ti,ab Searches diabetes in title OR diabetesMultiple field tags in abstractSupports truncation diabet*:ti Searches diabet* in title “diabetes Searches the phrase diabetes mellitusSupports phrase search mellitus”:ti,ab in the title or abstract fieldSupports phrase search (Diabetes next Searches the phrase diabetes mellitususing NEXT operator mellitus):ti,ab in the title or abstract field (diabetes near Searches for diabetes within 6 wordsSupports NEAR operator mellitus):ti,ab (established default) of mellitus in the title or abstract field. (diabetes near/5 Searches for diabetes within 5 words ofSupports NEAR/x operator mellitus):ti,ab mellitus in the title or abstract fieldSupport for more than one diabetes.ti and Searches diabetes in article title andterm in a search having endocrinology in sourcefield labels• Simply key your search term into the search box and click goThis is in example of a free text search where three concepts have been searched forindividually: 2 11. The red numbers tell you how many results (hits) have been found for each search term. You can also edit or delete individual search lines.You will now want to combine these three search concepts together to find itemsmentioning all of them.2 .Notice the ID column where each line of the search has been given a number, eg #1. 23
  24. 24. 3. It is these numbers, including the #, that you use to combine terms together 4. When searched, this combination also appears in the Current Search History 3 4Searching MeSHThis is a specific method of searching using the index terms assigned to many of therecords in the Cochrane Library. It is best used in conjunction with free text searchingcarried out within Search History.MeSH stands for Medical Subject Headings which is the name given to the thesaurus(the system of indexing terms, or descriptors) found on the Medline database.So far we have just searched in a free text style. This is generally fine when looking forinformation in the full text databases on the Cochrane Library, namely CDSR and to alesser extent DARE. However, the other databases only provide you with abstractsrather than whole documents. Therefore the most efficient way of searching CENTRAL,HTA, NHS EED and DARE is to use, in conjunction with free text searching, the indexterms assigned to these articles, because you cannot guarantee that your chosen termswill appear within the abstract itself.You can get directly to the MeSH search option from the Cochrane Library home pagebelow the simple search box or access it from within Search History.Below is a very simple free text search, conducted within Search History, for recordsabout the use of acupuncture to help people stop smoking. 24
  25. 25. You will now want to incorporate the relevant MeSH terms for your two concepts into thesearch.• Click on MeSH Search• Key in the term you want to match into the search box and click Thesaurus. This will search for likely terms within the indexing system. Click here for Thesaurus 1. Select the most appropriate term from the list 2. One or more trees of terms will appear. You can choose to search within a specific tree or all trees where your term appears. The default is all trees and explode. Explode will thereby also search for any narrower terms which you may see below your term and indented to the right. You can only Explode all trees. The latter is generally recommended 3. You can also either search only your chosen term (the one in red). 4. If you tick the box Go directly to Search History you will be taken directly back to the Search History screen once you have clicked View Results, allowing you to enter further terms or to start combining terms. 4 1 2 3Once you have repeated this process for each search concept you are in a position tocombine your free text and MeSH searches together, or indeed just combine the MeSHterms together: 25
  26. 26. 5 5. Notice the use of OR to join together the free text and MeSH versions of each concept. You will notice that there are fewer results just using the MeSH headings. This will be a much tighter, more focused search, and so long as the records on the database have been indexed correctly and consistently, should give you very relevant results. If you are specifically interested in trials this is a good method of searching CENTRAL. Using a combination of free text and MeSH terms will, on the whole, provide you with a larger number of results. While this method does ensure that you dont miss anything you will also pick up irrelevant results. Adding qualifiers 1. You may also add Qualifiers to your search terms. Qualifiers narrow your search to specific aspects of a topic, eg diet therapy, rehabilitation, complications, ultrasonography. 1 NB You can also search by qualifier alone, eg for the qualifier rehabilitation which could be attached to any thesaurus term. 26
  27. 27. Viewing, printing and saving search results Viewing results To view your search results from within Search History click on the relevant search statement of the set you want to look at it, eg #7 and #8. No matter which search method you have you used you will be automatically taken to a list of results in the Cochrane Database of Systematic Reviews, or the first database in which results appear (unless you have restricted your search to a particular database). 1 45 3 2 1. You will also be able to see how many records have been found in each of the other databases. Click on any of these database headings to switch to the results from that database. 2. Records are automatically displayed by Record Title, ie alphabetically, but you can re-order them to be displayed by Year, with the most recent items first, or by Match %, in order of likely relevance. 3. Again, you may restrict the records displayed in this particular database to completed reviews or protocols. 4. You may also have the option to Save Search or Edit Search. You will only see these options if you are viewing a single search statement which is not reliant on any other search statement. In the search example above this would apply to #1, #2, #4 and #5 but not the other lines of the search because they combine other search statements together. Choosing to edit a free text search statement will take you to an Advanced Search screen. Choosing to edit a MeSH search will take you back to the MeSH search screen. You will only be able to save the search if you are logged on to your account. See page 32 for more information on saving searches. 27
  28. 28. 5. To view a complete record click on RecordYou will see that the screen is now split in two, with the text of the systematic review onthe right (starting with an abstract and synopsis) and an index of the contents on the left.This method of navigation applies to all the main databases with the exception ofCENTRAL and CMR. 2 1The contents index has been re-organised and each heading is listed and explained onpage 29. Each section heading now appears in italics, Quick links; The review;Supplementary information; About this article1. The section Authors conclusions will give you a baseline outcome of the study split into implications for practice and implications for research.2. You should always check the date of the review, or its last update at the top of the review. If you are looking for the most up to date information on a topic theremay have been new trials published, which you will find on CENTRAL, since the reviewwas published.You can also look at the Index terms with which the review has been indexed whichmay help you to find similar studies.Comments about the systematic review can be added via Submit Feedback, and anyreplies from the authors read in Feedback. 28
  29. 29. Different sections of a Cochrane Systematic ReviewAbstract A structured abstract for the review, giving brief information on its background, objectives, search strategy, selection criteria, results and authors’ conclusionsPlain language Summarises the findings of the review in one paragraphsummaryQuick linksWhat’s new Details when published, updated and historical information of the reviewThe reviewBackground An overview of the condition and treatment on which the evidence is being reviewedObjectives Aims of the reviewMethods The types of study, participant, intervention and outcome measures that were required for a study to be requiredResults Detailed description of studies’ findingsDiscussion What the results showAuthor’s conclusions Gives a baseline outcome of the study, split into implications for practice and implications for researchAcknowledgements Acknowledgements of people who helped the authorsReferences References to studies included and excluded from the reviewFigures Other charts included in the reviewTables Tables of resultsSupplementaryinformationData and analyses Statistical analysis tablesAppendices Featuring relevant additional information and documentsFeedback Replies from authors concerning any feedback queries from this reviewAbout this articleContributions of Indicate which authors contributed to which part of the reviewauthorsDeclarations of interest Any potential conflict of interest on the part of the reviews authorsSources of support List of any internal or external sources of support provided to the review’s authorsIndex terms Look at the terms with which the review has been indexed to help find similar studiesSubmit feedback Comments about the systematic review can be added hereExport citation A tool to export your citation into a tool such as Reference ManagerProtocol and previous Any protocols and earlier versions of this reviewversions 29
  30. 30. Following up primary referencesIf you go to References and click on Links beside an article reference you may be takento a further link providing you with title and abstract information (note, not full text) forthat primary reference in PubMed which is the freely available online version of theMedline database.Interpreting graphsA key component of the systematic review is the statistical method of combining theresults of different primary studies that look at the same intervention. This is known asmeta-analysis and the results of a meta-analysis are usually shown in one or more oddsratio diagrams.At first glance they can be rather frightening but you dont need an in-depthunderstanding of statistics to be able to interpret them quite simply.This odds ratio diagram looks at the outcome of smoking cessation after 6 monthscomparing sham acupuncture (the control) with real acupuncture (the treatment).The odds ratio for each individual trial is shown by a blue square. The horizontal linethrough it represents the confidence interval for that result.The meta-analysis result is shown by the black diamond the width of which representsthe confidence interval. Confidence intervals are usually shown as 95% confidenceintervals, representing the range in which we can be 95% confident that the real result ofthe study lies.The vertical line through the diagram at the odds ratio of one is known as the line of noeffect. Anything crossing this line cannot show whether the intervention is any better orworse than the control. But results that fall to the left of the line indicate less of theoutcome in the experimental (treatment) group and results to the right of the line indicatemore of the outcome in the treatment group. Just be aware that more of an outcome isnot necessarily a good thing, ie when you are measuring mortality. 30
  31. 31. Saving and printing search results You can print entire records, including the very lengthy systematic reviews, if you view them as PDF files. Simply use the integral print and save icons within Adobe Acrobat. Otherwise you can print, or save to file, selected citations.1 2 3 1. Put a tick in the box beside the individual references you are interested in or click select all at the bottom of the list 2. Select all will pick up the entire search set from the database you are viewing but you can select records from different databases and export them together. 3. Click Export Selected Citations This screen will appear: 1 2 1. You can choose to select just the Citation or Abstract and citation from the drop down Export Type box 2. Click Go 31
  32. 32. You will then be asked whether you want to open the file on your computer now or tosave it to your hard drive or a floppy disk.N.B. There is a distinction made on the Cochrane Library between Save Search andSave Search Strategy. Saving a search allows you to save individual search statements, or lines of a search Saving a search strategy allows you to save a string of search commandsSaving your searchYou will see this option when you are viewing the results of individual search statements. 1. Click on Save Search. If you are not already logged on you will be asked to enter your username and password. 1 32
  33. 33. Saving your search strategy Saving a search strategy allows you to save a string of search commands 1. You may save your search strategy from within the Search History function as long as you are logged on to your account. 2. You may also clear your history at any point. 21 Once you have clicked Save Search Strategy the dialog box below appears for you to enter the name of your search and any comments. 1 1. Then click Save Search Strategy The next time you log on the Cochrane Library you will be able to access your saved searches and search strategies by clicking Saved Searches below the simple search box on the home page or from within whichever search mode you are in. 33
  34. 34. Saved searches do not currently appear in the My Profile banner at the top of thescreen. 1 3 2 1. To run the search click Run 2. To delete any saved searches, check the tick box(es) and click Delete Checked Items 3. To export your saved search, click export. This allows you to download a copy of your search strategy to include it in a word processing document. Select either open or saveEach line of your search will be displayed separately. The file is in .txt format, as shownbelow. 34
  35. 35. Setting alertsCurrently, alerts may be set for individual search statements, not full search strategies. To activate the alert click on this link• If your search can be set as an alert you will see Activate Alert beside it.• To cancel an alert click on Stop AlertYou will be sent an email to the address you gave when you set up your profile if newrecords matching your search criteria are added to the database at subsequent quarterlyupdates.You may set various options for your alerts by clicking My Profile in the banner at thetop of the screen. 35