Training guide. The Cochrane Library. Produced by: Mary Last Hospital Librarian Ipswich Hospital NHS Trust. November 2008 V 1.3

Transcription

1 Training guide The Cochrane Library Produced by: Mary Last Hospital Librarian Ipswich Hospital NHS Trust November 2008 V 1.3

2 2

3 Contents 1. Overview - sources of research-based evidence Sources of research-based evidence... 4 The hierarchy of evidence Introduction to the Cochrane Library What is the Cochrane Library?... 6 When to use the Cochrane Library... 6 Background and history of the Cochrane Library... 7 The databases Getting started Accessing the Cochrane Library Site registration and password Explaining the home page Browsing the Cochrane Library Browsing the main databases Browsing the Cochrane Database of Systematic Reviews Browsing by Topic Browsing by Review Group Searching the Cochrane Library Search tips and tricks Simple search Advanced search Search history Searching MeSH Viewing, printing and saving search results Viewing search results Interpreting graphs Saving and printing search results Saving a search Saving a search strategy Re-running searches and setting alerts

4 Overview - sources of research-based evidence Evidence-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 The range of the external clinical evidence available to health care professionals is often described as a hierarchy and this is shown on the following page, from individual opinion 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 the primary journal literature by searching databases search as Medline. There are, however, specialist resources that you can go to which evaluate and summarise available research evidence when you want to know about the effectiveness of a particular health care intervention. These can be divided into: Reviews e.g. 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 8. Digests e.g. Clinical Evidence Digests identify the major evidence on particular topics and provide key messages. Guidelines e.g. National Library of Guidelines Guidelines provide recommendations for effective practice based on current evidence. If you find a systematic review or summary of current evidence which answers your question you will be saved the work of searching databases for journal literature as well as much of the reading and critical appraisal involved. 4

5 5

6 Introduction to the Cochrane Library What is the Cochrane Library? The Cochrane Library is described as the best single source of reliable information on the effects of interventions in health care. It is designed to provide information and evidence to support decisions taken in health care and to inform those receiving care. The Cochrane Library is a collection of databases containing systematic reviews, health technology assessments, economic evaluations and controlled trials. More information about each database can be found on page 8. Some databases provide full-text articles, some just bibliographic details with abstracts. When to use the Cochrane Library The whole of the Cochrane Library is concerned with the effectiveness of interventions for 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) 6

7 Background and history of the Cochrane Library Since 1996, systematic reviews prepared and maintained by the Cochrane Collaboration have been published in The Cochrane Library, along with bibliographic and qualityassessed material on the effects of health care interventions submitted by others. Cochrane reviews are a highly regarded source of evidence about the effects of health care interventions and widely thought of as being of better quality, on average, than their counterparts in print journals. By the mid 1980s, people had begun to recognise that it was impossible to interpret the results of any one study in isolation, and that critical summaries were needed to put the results into context. Indeed, it began to be realised that, because a systematic approach to assessing research on the effects of health care interventions was not being used, patients were suffering and even dying unnecessarily. This was illustrated by comparing advice in textbooks and the information that could have been available had a scientifically defensible approach been used to cumulate evidence as it emerged. In 1979 Archie Cochrane had issued a call to assemble a critical summary, adapted periodically, of all relevant randomized controlled trials" and one of the fields in which people had begun to heed this call by the mid 1980s was perinatal medicine. Work had begun on developing registers of controlled trials of interventions during pregnancy, labour and early infancy, and the advantages of a more systematic approach to reviewing evidence about the effects of health care interventions, sometimes combining data from similar studies to create an overall estimate of effect (meta-analysis), had also been demonstrated, both in stand alone reviews, and in setting the results of new studies in context. It was clear from the start of the Cochrane Collaboration in 1993 that it would be many years before the majority of reliable research studies assessing the effects of health care interventions could be placed in the context of a systematic review. Even with thousands of Cochrane reviews currently underway, and results already available from 2,000 of these, there is still a large amount of work to be done. The latest estimate is that approximately 10,000 Cochrane reviews are needed to cover all health care interventions that have already been investigated in controlled trials, and these reviews will need to be updated at the rate of 5,000 per year. If the growth in The Cochrane Collaboration continues at the pace of the last few years, this target will be reached within the coming ten to fifteen years. It was also clear in 1993 that the Cochrane Collaboration was not the only group producing high-quality reviews. Additionally, it was missing one essential element - the register of trials that provided the source material for the systematic reviews. 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 trials These collections were viewed as part of a hierarchy of evidence, ranging from regularly updated reviews, to high-quality reviews published elsewhere, to reports of individual controlled trials. 7

8 There are now six main databases plus two others giving information about the Cochrane Collaboration and its Review Groups. Further information on each of the main databases can be found below. Further information The Cochrane Collaboration's web site is a useful source of information. The Newcomer's Guide on it provides background information on the Cochrane Collaboration and its systematic reviews. An article about the genesis of the Cochrane Library between 1988 and 2003 can be found at The databases Cochrane Reviews (Cochrane Database of Systematic Reviews - CDSR) A systematic review identifies an intervention for a specific disease or other problem in health care, and determines whether or not this intervention works. To do this authors locate, appraise and synthesise evidence from as many relevant scientific studies as possible. They summarise conclusions about effectiveness, and provide a unique collation of the known evidence on a given topic, so that others can easily review the primary studies for any intervention. Systematic reviews differ from other types of review in that they adhere to a strict design in order to make them more comprehensive, thus minimising the chance of bias, and ensuring their reliability. Rather than reflecting the views of the authors, or being based on a partial selection of the literature, (as is the case with many articles and reviews that are not explicitly systematic), they contain all known references to trials on a particular intervention and a comprehensive summary of the available evidence. The reviews are therefore also valuable sources of information for those receiving care, as well as for decision makers and researchers. Due to the growing interest in the methodological advances in the synthesis of studies of diagnostic tests, from Issue CDSR has included systematic reviews of diagnostic test accuracy. These are based not on systematic reviews but mainly on cross sectional studies. Other Reviews (Database of Abstracts of Reviews of Effects - DARE) DARE includes structured abstracts of systematic reviews from around the world which have 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 criteria are included in DARE. These reviews cover topics that have yet to be addressed by a Cochrane review. Clinical Trials (Cochrane Central Register of Controlled Trials - CENTRAL) 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 contain the full text of the article. 8

9 Trials are identified from multiple sources, including searches of bibliographic databases, hand searches of many hundreds of journals and conference proceedings, and searches of other trial registers. Methods Studies (Cochrane Database of Methodology Reviews - CDMR) Cochrane Methodology Reviews are full-text systematic reviews of methodological studies. Highly structured and systematic, evidence from methodological research is included or excluded on the basis of explicit quality criteria, thus minimising bias. Each review covers a specific and well-defined area of methodology. Data from studies are often 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, the review may also include graphs presenting the data from each individual study. Protocols provide information about reviews which are currently being written. They summarise the background and the rationale of the review. Technology Assessments (Health Technology Assessment Database - HTA) This database contains information on healthcare technology assessments (defined as prevention and rehabilitation, vaccines, pharmaceuticals and devices, medical and surgical procedures and the systems within which health is protected and maintained). The database contains details of ongoing projects and completed publications from health technology assessment organisations. HTA records follow a standard structure. Some records contain the title of the project, with the name of the centre responsible and an indication of where further details can be obtained. Other records contain publication details, with structured abstracts where available. Records do not, in either case, contain the full text of the report. Economic Evaluations (NHS Economic Evaluation Database - NHS EED) This database contains structured abstracts of articles describing economic evaluations of health care interventions. The articles are identified by searching through key medical journals, bibliographic databases and less widely available literature. A paper will be included if it provides a comparison of treatments and examines both the costs and outcomes of the alternatives. The database also includes bibliographic details of articles examining relevant topics, (for example the burden of illness, economic methodology papers, and reviews of economic evaluations), and short abstracts of studies originally included in the Department of Health Register of Cost-Effective Studies. Records do not contain the full text of the original article. 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 Getting started Accessing the Cochrane Library You can either go directly to the Cochrane Library at or click on the link Cochrane Library under the heading Evidence Based Reviews in the central pane of the National Library for Health The databases are updated quarterly. Also on the National Library for Health site under Evidence Based Reviews you will find links to DARE, the HTA Database 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 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. Click Log In in the top right hand corner of the screen This will take you to the main Wiley InterScience home page. Click Register Now Fill in the registration form Your address and the password you choose will be used as your username and password for the future. Try to register using your work address and to avoid an address ending in.com. You must also check the box to indicate that 10

11 you have read the Terms of Usage. The information you enter will not be used by a third party. Click Submit Registration You will receive an 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: Type Cochrane in the search box Check the radio button Publication Titles Click Go 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. Always remember to Log Out when you have finished a search session. 11

12 Explaining the home page This is the Cochrane Library banner. To get back to the home page at any time click Home 2. Links enabling you to browse the resources on the Cochrane Library 3. A simple search box and links to other searching methods (see section 5 below) 4. Information on the most recent additions to the Library, which is updated quarterly 12

13 Browsing the Cochrane Library The main databases can be browsed alphabetically by title (and the Cochrane Reviews in a variety of additional ways, see below) by clicking on their name. 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 18 for Advanced Searching. This is the A-Z browse screen for the Cochrane Database of Systematic Reviews: Note that the default display is all records (i.e. protocols and reviews) but you can choose to just view completed reviews or protocols only. On the Cochrane Database of Systematic Reviews and the Methodology Reviews Database you may find the following symbols after records: A full review, complete with results and discussion The outline of a review in preparation, including the background, rationale and methods A full-text systematic review of methodological studies Cochrane diagnostic test accuracy reviews. These are based not on randomised controlled trials but mainly on cross sectional studies A new review or protocol that has been published in the most recent quarter A new search for studies has been conducted for an existing review There has been an important change to the conclusions of the The protocol has been amended to reflect a change of scope A review or protocol has been withdrawn (may have been considered out of date). Reasons for withdrawal are specified in the document 13

14 The review includes comments. Readers can submit comments which are incorporated into the review together with answers and feedback from the review authors Browsing the Cochrane Database of Systematic Reviews The Cochrane Database of Systematic Reviews can be browsed by topic, new or updated reviews, A-Z or by Cochrane Review Group. Browsing by topic Use the drop-down list to browse review topics by your chosen Cochrane Collaborative Review Group. Selecting a review group shows the broad topic areas which that group covers. Clicking on a heading opens out further sub-sections until you find a review of interest. Browsing by review group This brings up a list of the same review groups as searching by topic. But this time when you select the name of the review group you are interested in you are presented with a complete list of reviews for that group. This are split into protocols and reviews, arranged alphabetically within each section. 14

15 Searching the Cochrane Library There are four ways of searching the Cochrane Library: 1. Simple search (see page 17) 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 18) 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 20) 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 22) 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. Search tips and tricks Unless you are searching using MeSH you will be entering your search terms in free-text format. There are number of rules which will help you get the best out of the databases. Combining terms using AND or OR The Cochrane Library supports the use of AND and OR to connect search concepts together, e.g. 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, e.g. postnatal depression 15

16 Similarly, OR can be replaced by a comma, e.g. cancer, neoplasm Phrase searching If you want two words to be adjacent to each other the phrase must be enclosed in double inverted commas, e.g. "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, e.g. postnatal near depression You can change how many words intervene, e.g. postnatal near/3 depression Spelling tips Plurals are automatically searched for, e.g. foot would also find feet If you don't want to find the plural, type in the singular form in double inverted commas, e.g. "foot" Common spelling variations are also found automatically, e.g. randomise / randomize 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, e.g. 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, e.g. *natal would find prenatal or antenatal or postnatal 16

17 In the middle of the words to pick up variations, e.g. 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, e.g. h*ematology would find haematology or hematology The wildcard character should also be used to replace potentially accented letters within words, e.g. "m*ni*re's disease" to find ménière's disease Punctuation 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, e.g. either St John's wort or St Johns wort both work fine 17

18 Simple search You can therefore conduct simple searches using the above search tips in the single search box on the Cochrane Library front page: Key in your search terms and click Go As a default the Title, Abstract and Keywords fields are searched, but you can also assign your search to other fields of the database, e.g. just the record title. For more information about the various database fields see page 19. 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 OR'ed 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*) 18

19 Advanced Search Advanced search allows you to enter several search concepts in up to five search boxes at one time. However there are problems with this method and using Search History is recommended in preference (see page 20). Click on Cochrane Advanced Search below the single search box on the home page You will see five interconnected search boxes and various options for restricting your search. Database fields All text Record title Author Abstract Keywords Tables Your term in any field of all the databases. For CDSR and CDMR this will be the full text of the systematic review. Article titles only Authors of articles only Abstracts only Your term will be in the Index field in all databases except CDMR which doesn 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. Your term will be in the Table field. Tables only appear in the CDSR and CDMR databases. 19

20 Publication type Source DOI 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. Searches the title field or the field which details the source of the original article referenced in the database. A search for the DOI number in the DOA field of CDSR and CDMR. (DOI means Digital Object Identifier see Restrictions and limits You can also choose to: Restrict your search to particular databases within the Cochrane Library Select just new, updated, commented or otherwise altered records (this applies to CDSR and CDMR only) Select a date range for your search There is little value in restricting your search to individual databases because search results 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 the search method you use. On the whole we would recommend not using Advanced Search. This is because of the misleading way in which terms are combined between the five search boxes. Just as with the hint on using Simple Search on page 18 if you do use Advanced Search be sure to incorporate all synonyms within a single search box and not split them up. For example, do not construct a search statement such as: OR AND AND "otitis media with effusion" "glue ear" antibiotic child* Instead, you should construct it as: AND AND "otitis media with effusion" or "glue ear" antibiotic child* 20

21 Search history Clicking on Search History below the single search box on the home page takes you to a 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 of several search statements and then use commands to combine those individual terms together. This forces you to think carefully about the construction of your search statement. It encourages you to search for one term, or concept, at a time, and additionally allows you to combine free text searching with MeSH searching (see page 22) to build up a thorough search strategy. In addition to your search term you can Restrict your search to a particular database Select just new, updated, commented or otherwise altered records (this applies to CDSR and CDMR only) Select a date range Searching fields You can include field labels as part of your search statement to find the occurrence of words or phrases in particular fields such as the title or author. Available field 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 is searched as the default 21

22 The following chart gives specific examples of how field labels can be used within a search. Options Example Action No field tag Diabetes Searches diabetes in ALL text fields (current default) One field tag Diabetes:ti Searches diabetes in title field Multiple field tags Diabetes:ti,ab Searches diabetes in title OR diabetes in abstract Supports truncation diabet*:ti Searches diabet* in title Supports phrase search diabetes Searches the phrase diabetes mellitus mellitus :ti,ab in the title or abstract field Supports phrase search using NEXT operator (Diabetes next mellitus):ti,ab Searches the phrase diabetes mellitus in the title or abstract field Supports NEAR operator (diabetes near mellitus):ti,ab Searches for diabetes within 6 words (established default) of mellitus in the title or abstract field. (diabetes near/5 Supports NEAR/x operator Searches for diabetes within 5 words of Support for more than one term in a search having field labels mellitus):ti,ab diabetes.ti and endocrinology.so mellitus in the title or abstract field Searches diabetes in article title and endocrinology in source Simply key your search term into the search box and click go This is in example of a free text search where three concepts have been searched for individually: 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 items mentioning all of them. Notice the ID column where each line of the search has been given a number, e.g. #1. It is these numbers, including the #, that you use to combine terms together: 22

23 MeSH search 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. 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 for information in the full text databases on the Cochrane Library, namely CDSR, CDMR and to a lesser extent DARE. However, the other databases only provide you with abstracts rather 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 index terms assigned to these articles, because you cannot guarantee that your chosen terms will appear within the abstract itself. You can get directly to the MeSH search option from the Cochrane Library home page below the simple search box or access it from within Search History. This is a very simple free text search, conducted within Search History, for records about the use of acupuncture to help people stop smoking. 23

24 You will now want to incorporate the relevant MeSH terms for your two concepts into the search. 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. Select the most appropriate term from the list 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 latter is generally recommended. You can also either search only your chosen term (the one in red) or to explode it, thereby also searching for any narrower terms which you may see below your term and indented to the right. 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. Once you have repeated this process for each search concept you are in a position to combine your free text and MeSH searches together, or indeed just combine the MeSH terms together: 24

25 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 don't miss anything you will also pick up irrelevant results. Adding qualifiers You may also add Qualifiers to your search terms. If you are familiar with searching the National Library for Health databases, e.g. Medline and CINAHL, these are the same as the subheadings which you can assign to the thesaurus terms. Qualifiers narrow your search to specific aspects of a topic, e.g. diet therapy, rehabilitation, complications, ultrasonography. NB You can also search by qualifier alone, e.g. for the qualifier rehabilitation which could be attached to any thesaurus term. 25

26 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, e.g. #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) 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, i.e. 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. You may also have the option to Save Search or Edit Search. You will only see Saved Search 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. You will only be able to save the search if you are logged in to your account. See page 30 for more information on saving searches. Choosing to edit a free text search statement will take you to the Search History screen. Choosing to edit a MeSH search will take you back to the MeSH search screen. 26

27 4. To view a complete record click on Record You will see that the screen is now split in two, with the text of the systematic review on the right (starting with an abstract and plain language summary) and an index of the contents on the left. This method of navigation applies to all the main databases with the exception of CENTRAL and CMR. You can either navigate through the entire review using the Next button, click on various headings in the index to jump to that section, or view the entire review as a PDF file. The section Authors' conclusions will give you a baseline outcome of the study split into implications for practice and implications for research. You should always check the date of the review, or its last update. If you are looking for the most up to date information on a topic there may have been new trials published, which you will find on CENTRAL, since the review was published. Full information about the publication and version dates of the review appear after the authors names and the What s new section provides a history of the review s evolution. You can also look at the Index terms with which the review has been indexed which may help you to find similar studies. Comments about the systematic review can also be added and read via Submit feedback. Following up primary references If you go to References and click on Links beside an article reference you may be taken to a further link providing you with title and abstract information (note, not full text) for that primary reference in PubMed which is the freely available online version of the Medline database. 27

28 Interpreting graphs A list of all tables contained in the review can be found by clicking on the link Tables in the review s index. A key component of the systematic review is the statistical method of combining the results of different primary studies that look at the same intervention. This is known as meta-analysis and the results of a meta-analysis are usually shown in one or more odds ratio diagrams. At first glance they can be rather frightening but you don't need an in-depth understanding of statistics to be able to interpret them quite simply. This odds ratio diagram looks at the outcome of smoking cessation after 6 months comparing sham acupuncture (the control) with real acupuncture (the treatment). The odds ratio for each individual trial is shown by a blue square. The horizontal line through it represents the confidence interval for that result. The meta-analysis result is shown by the black diamond the width of which represents the confidence interval. Confidence intervals are usually shown as 95% confidence intervals, representing the range in which we can be 95% confident that the real result of the study lies. The vertical line through the diagram at the odds ratio of one is known as the line of no effect. Anything crossing this line cannot show whether the intervention is any better or worse than the control. But results that fall to the left of the line indicate less of the outcome in the experimental (treatment) group and results to the right of the line indicate more outcome in the treatment group. Just be aware that more of an outcome is not necessarily a good thing, i.e. when you are measuring mortality. The most recent published reviews (from issue 3, 2008) now include a Summary of findings table towards the top of the review. 28

29 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. Put a tick in the box beside the individual references you are interested in or click select all at the bottom of the list 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. Click Export Selected Citations This screen will appear: You can choose to select just the Citation or Abstract and citation from the drop down Export Type box Click Go You will then be asked whether you want to open the file on your computer now or to save it to your hard drive or external device. There is a distinction made on the Cochrane Library between Save Search and Save 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 commands 29

30 Saving your search You will see this option when you are viewing the results of individual search statements. You must first log on to your account. Then click Save Search. Saving your search strategy Saving a search strategy allows you to save a string of search commands You may save your search strategy from within the Search History function as long as you are logged on to your account. You may also clear your history at any point. 30

31 Once you have clicked Save Search Strategy a dialog box appears for you to enter the name of your search and any comments. Then click Save Search Strategy Re-running searches and setting alerts 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. To re-run a search click Run To delete any saved searches, check the tick box(es) and click Delete Checked Items You can also export your saved search. This allows you to download a copy of your search strategy to include it in a word processing document. Click export Select either open or save Each line of your search will be displayed separately. The file is in.txt format. 31

32 Currently, alerts may be set for individual search statements, not full search strategies. If your search can be set as an alert you will see Activate Alert beside it. To activate the alert click on this link To can cel an alert click on Stop Alert You will be sent an to the address you gave when you set up your profile if new records matching your search criteria are added to the database at subsequent quarterly updates. You may set various options for your alerts by clicking My Profile in the banner at the top of the screen. 32