Information Services & Systems The Cochrane Library An introductory guide Sarah Lawson Information Specialist (NHS Support) sarah.lawson@kcl.ac.uk April 2010
Contents 1. Coverage... 3 2. Planning your search... 3 3. Accessing the Cochrane Library... 4 4. Free text searching... 5 Phrase searching... 5 Wildcards... 6 Searching for authors, titles etc.... 6 5. MeSH (subject) searching... 7 6. Search history... 9 7. Combining searches... 9 8. Displaying and saving results... 11 9. Browsing... 15 10. Logging out... 15 Aims & Objectives To introduce trainees to the Cochrane Library, including when to search the database, planning searches and hands-on searching. By the end of the session the students should: Be aware of the coverage of the databases which make up the Cochrane Library Understand when to search the Cochrane Library Be able to choose keywords and structure a search for in the Cochrane Library Understand how to search for phrases and use wildcards Understand the principles of MESH searching Be able to conduct a search in the Cochrane library, using keywords and MESH Be able to combine searches using the search history Be able to display, print and save records from different databases within the Cochrane Library Be aware of the key sections to look at in a Cochrane Review
1. Coverage The Cochrane Library is a key source of information on the effects of interventions in health care. It is designed to provide information and evidence to support decisions taken in health care. It incorporates six databases; five of these provide coverage of evidence based practice (EBP) Cochrane Database of Systematic Reviews, Other reviews (Database of Abstracts of Reviews of Effects), Clinical trials (Cochrane Central Register of Controlled Trials), NHS Economic Evaluation Database (NHS EED) and Health Technology Assessment Database (HTA). The other database focuses on research methodology. When to use the Cochrane Library When you wish to search for reliable evidence about the effectiveness of interventions, e.g. treatment; diagnosis and screening; health promotion; organisation of care When not to use the Cochrane Library You should not use the Cochrane Library to search for general healthcare questions - causal, prognosis, epidemiology, etc. ; statistics (prevalence and incidence); primary research other than controlled trials; current research. 2. Planning your search Before you start searching for information, it is a good idea to plan your search. Don t try to search using whole sentences. The more words you use at once the fewer results you will find! Instead, think of the most important keywords you need to use and search for these separately. You should also try to think about any other synonyms or alternative spellings to describe your subject. You may find it helpful to think of PICO to help you pick out the keywords. Using these questions can help you to pick out the most important concepts. Page 3
P Patient (Who is the patient? What part of the population are you interested in?) I Intervention (What treatment, health promotion intervention or therapy do you want to investigate?) C Comparison (What do you want to compare this treatment to? This is optional, you may not have a comparison.) O Outcome (What is the expected or desired outcome of the intervention? What do you want to achieve?) Example: Should you always prescribe antibiotics for children with acute otitis media? P children (is age an important factor here?), middle ear infection, otitis media I antibiotics (dose: levels, frequency) C no intervention O side-effects, remission; cost-effectiveness We will now try carrying out a search for research into the effectiveness of antibiotics for otitis media in children. 3. Accessing the Cochrane Library You do not need to register for general access, but you can register online if you would like to save your searches. Go to www.hilo.nhs.uk, click Search for Evidence Click on the Cochrane Library link. Page 4
The screen will look as below: Free text search box Browse Cochrane reviews by topic Advanced search including MeSH (subject) searches and Search history 4. Free text searching Phrase searching Each word entered within the Search field is searched individually. To search for exact phrases, enclose the words in quotation marks eg otitis media. Page 5
Wildcards To retrieve variations of a search term, use the wildcard symbol *, e.g. arter* would retrieve artery, arteries, arterial etc. N.B. plurals are searched for automatically, e.g. antibiotic would retrieve antibiotics. Searching for authors, titles etc. you can restrict your search to particular fields eg Record Title, by using the drop down menu We will start by looking for antibiotics in the free text search box on the right. Click on Go to carry out the search. This brings up the results screen below: You can see how many references there are on this topic in each database. Page 6
5. MeSH (subject) searching The Medical Subject Heading (MeSH) Search is based on the National Library of Medicine s controlled vocabulary thesaurus of medical subject headings. Not all records on the Cochrane Library are indexed using MeSH. To ensure that the maximum number of records is retrieved, a combination of MeSH and free text searching should be used. The following methods can be used for searching: MeSH Tree click on Go to MeSH Trees to view a tree structure of related terms the MeSH tree displays your term in a hierarchical context, which means that you can easily find a more general term or a more specific term Thesaurus click on Thesaurus to display the complete index of all MeSH descriptors that include the word (N.B. if you try a MeSH tree search and the term cannot be found, then Cochrane will automatically try searching the Thesaurus) click on an index term to select it one or more qualifiers (e.g. diagnosis, therapy) can be selected to focus on aspects of the topic. Narrower terms (e.g. specific antibiotics) will be included by default unless the Search this term only box is selected Click on Advanced search on the home page, then MeSH Search and enter antibiotics in the text box. Click on thesaurus. This will bring up the screen on the following page: Page 7
This brings up the MeSH tree below Narrower topics (e.g. specific antibiotics) are included by default Click on Go directly to Search History and View Results Page 8
6. Search history Searches run during your current session are saved to your Search History profile. to view results from a previous search, go to Advanced Search on the home page, select Search History then click on the relevant search line you can also Edit or Delete individual searches within Search History. current searches are stored cumulatively until the Clear History button is used 7. Combining searches You can also combine searches within search history (N.B. you need to use the # key e.g. #1 and #2) AND searches for records containing all the search terms used this will reduce the number of hits, but those found will be more relevant eg antibiotics and otitis media OR searches for records that contain any of the terms best used for synonyms, eg otitis media with effusion or glue ear; or free-text(s) and subject heading(s) on the same topic, e.g. antibiotics or Anti-Bacterial Agents. NEXT is used to find terms which appear adjacent to each other in the record use NEAR/n to find words occurring within n words of each other e.g. community NEAR/4 care would retrieve Community care or Care in the community Page 9
Combine the free text and MeSH searches for antibiotics using OR in the search history. Notice that this increases the number of results. Conduct similar free-text and MeSH searches for otitis media, and then combine these in search history. To search for exact phrases use quotes, e.g. otitis media. Page 10
Combine the different sets together using AND Click on the final line to view results. Notice that there are fewer results than in the previous lines. 8. Displaying and saving results The records found within each database are displayed in the Search Results section. The first screen displays results for Cochrane Reviews (N.B. Records will be marked either Review for full Review, or Protocol (planned review); the results from other databases can be viewed by selecting the relevant link. Cochrane Reviews and Methodology Reviews contain full text records. Other databases contain only citations (some with abstracts). You can view, save, and print. Page 11
Click on the Record title to access further details about a document Click on the name of a database, e.g. Other Reviews, to access results from that database Click on the Record title of the review by Glasziou. Page 12
Check the date when the review was last amended Access the contents page on the left, including author s conclusions Page 13
Selecting records for saving Select the result(s) you wish to save by ticking the box(es) on the left Click on export option at the bottom of the screen On the following screen: select Export type (Citation or Abstract and citation) and File Type (PC, Macintosh, or Unix or Linux) and click on Go to save to a selected drive, select Save. Page 14
9. Browsing If you click on Browse by Topics, you will see a list of the Cochrane Review Groups. Click on a Review Group and then sub-headings You can then open up a review by clicking on html or PDF link. Other Cochrane databases can also be browsed (except for the Trials database). Browsing these will bring up an A-Z list of documents. 10. Logging out You only need to log out if you have logged in: select Log out in the top right corner. You will automatically get timed out after 15 minutes of inactivity. Page 15
11. Exercises Exercise 1 Please tick one of the boxes for each enquiry, to show whether you think the Cochrane Library would be helpful in answering this question. Question 1. What research has been carried out on self-esteem among nurses working in psychiatric setting community hospitals? Yes No Perhaps 2. Is health education effective in improving compliance with HRT? 3. Are there reviews of continuing or long-term care? 4. Has any research been carried out on interventions to improve immunization rates? 5. What is the effectiveness of the various interventions to reduce falls in elderly people? 6. Are there any studies on incidence and prevalence of irritable bowel syndrome? 7. How often should nurses wash their hands? 8. How many people have type 2 diabetes in the UK? 9. How to patches and gum compare when attempting to stop patients from smoking using nicotine replacement therapies? Exercise 2 Carry out a search on hypnosis and smoking cessation. Remember to use free-texts, with truncation if needed, and subject headings. Combine your searches appropriately and view your results. Exercise 3 Carry out a search on interventions for pressure sores. Exercise 4 Is there any evidence that praying can affect people s health? Page 16
Exercise 5 Find a Cochrane Review on the use of fish oils for type two diabetes. Remember to consider synonyms and alternative terms for each search topic. Answers (correct as of August 2009) Exercise 1 Question Yes No Perhaps 1. What research has been carried out on self-esteem among nurses working in psychiatric setting community hospitals? This question is missing both a healthcare outcome (selfesteem is not a healthcare condition, although low selfesteem might be) and an intervention. 2. Is health education effective in improving compliance with HRT? This is typical of the sort of question that you should attempt to answer using the Cochrane Library. In this particular case, there are definitely some reviews on compliance in general, and the results from these might be applicable to more specific drug regimes. 3. Are there reviews of continuing or long-term care? This is a very broad question! What aspects of care are we talking about? What is the effectiveness question here? A very general search might produce some results about the effectiveness of certain types of care, but a more focused question would produce better results. Page 17
4. Has any research been carried out on interventions to improve immunization rates? If this was rephrased as an effectiveness question, e.g. what are effective interventions to improve immunization rates, then the Cochrane Library might have information to answer it. However if the enquiry is really about the types of interventions, then searches on Medline or other databases might be more appropriate. 5. What is the effectiveness of the various interventions to reduce falls in elderly people? Typical of the sort of enquiry that should be answered by searching the Cochrane Library. 6. Are there any studies on incidence and prevalence of irritable bowel syndrome? The Cochrane Library is aimed at an international audience and statistics on the epidemiology of diseases are not likely to be very detailed or very local. More detailed national and local statistics are probably better found in other resources. 7. How often should nurses wash their hands? Is this asking to reduce the spread/risk of infection? If so, the Cochrane Library would be appropriate to use. 8. How many people have Type 2 diabetes in the UK? Another statistics question that would be better answered elsewhere. 9. How do patches and gum compare when attempting to stop patients from smoking using nicotine replacement therapies? This is an example of comparing the effectiveness of two different treatments. A good example of the type of question that can be answered using the Cochrane Library. Page 18
Exercise 2 The following search: #1 smoking cessation #2 SMOKING CESSATION - (MeSH (subject heading) search) #3 #1 or #2 #4 hypno* #5 HYPNOSIS - (MeSH (subject heading) search) #6 #4 or #5 #7 #3 and #8 Finds records in several databases, including a Cochrane Review. The Cochrane Review is several years old, so you would need to check the trials database for more recent research. These should be considered alongside the systematic review, but remember that you will need to appraise them for quality first. Exercise 3 A free text search for pressure sores or pressure ulcers finds records in several databases. For some of the interventions, the reviews are several years old, so you would need to check the trials database as above. Exercise 4 Is there any evidence that praying can affect people s health? The following search: #1 pray* #2 FAITH HEALING - (MeSH (subject heading) search) #3 #1 OR #2 will find records in several databases, including a recently updated Cochrane Review. Page 19
Exercise 5 Fish oils for type two diabetes. Hint: it s always important to try and think of alternative terms for your search concepts. When searching for omega-3, make sure you insert the hyphen, as the Cochrane Library cannot search for isolated numbers. #1 diabet* #2 DIABETES-MELLITUS - (MeSH (subject heading) search) #3 (#1 or #2) #4 (fish NEAR oil*) #5 FISH-OILS - (MeSH (subject heading) search) #6 omega-3 #7 #4 or #5 or #6 #8 #3 and #7 This search finds records in several databases, including a recent Cochrane Review. Page 20