In this presentation I intend to: Tell you something about Cochrane and what we do Talk about how we go about doing literature searches for systematic reviews (something which Trevor has asked me to look at with you) Do some group work on searching the literature (computer access)
Cochrane Collaboration, named after Archie Cochrane, an epidemiologist who called for systemic reviews of clinical trials in the 1970s. Lancet: The Cochrane Collaboration is an enterprise that rivals the Human Genome Project in its potential implications for modern medicine .“ What came out of this was the Cochrane Library, incorporating a database of systematic reviews and a central clinical trials register.
Cochrane itself consists of over 50 review groups worldwide, each with a different medical specialty, all producing systematic reviews for the Cochrane Library
Established in US in 1994, moved to Manchester in 1996
Over 700 authors based all over the world
These are some of the challenges for the future Pt 2 – At the moment we have a grant from the NHS which runs until 2015 as primary source of funding, but future is uncertain after that Pt 3 – particularly want to get consumers involved Pt 4 – Aim is to get results of the reviews into practice, many reviews are incorporated into guidelines Pt 5 – Reviews have to be updated every 2 years, maintaining this whilst publishing new reviews is a real challenge The solution of our co-ordinating editors Helen Worthington and Jan Clarkson was to develop a global alliance of professional and research bodies in dentistry which could help support us in our work
Global Alliance is now off the ground – here are some of the benefits for members The payoff will be to improve quality, to hopefully get more consumers (or patients) involved and enhanced product in podcasts and journal club material
So that’s some background to Cochrane, now we’re going to look at the second part of this session, which is how to search the literature systematically. This is my role for Cochrane. This is the foundation of a good systematic review, but also of a great research project in general, you need to be able to search the literature. The clearer the research question and concepts, the easier the search will be.
I believe you looked at Pico last year with Trevor? Here’s a reminder and some examples.
We don’t search for comparisons or outcomes. The comparison is often placebo or no treatment, so there’s no point. Outcomes may not appear in the abstract of a citation on a database, so searching for these could limit your search.
As a minimum… CINAHL – Oral hygiene for nursing home residents PsycINFO – dental anxiety, hypnosis
We’re going to look at the two methods for searching the literature via a database like MEDLINE – controlled vocabulary and free text.
MeSH are a series of subject headings, which allow you to search across articles on the same subject, which have been categorised and tagged with the headings.
Demo with dental caries. If you explode dental caries, it will also pick up those articles indexed with dental fissures and root caries
Dental caries AND chlorhexidine Dental caries OR dental decay Dental caries NOT root
This is an example of how a search comes together for PubMed. The first two lines are about alendronate. Line 1 is the MeSH heading. MH tells pubmed that this is a MeSH heading, and the noexp tells PubMed that we don’t want to explode the term. Line #2 is synonyms for Alendronate, or related terms. These are brought together in line #3, which tells pubmed you want to search for all of these terms. Lines #4-#6 cover the menopause, brought together by line 7. Again, line #4 is the MeSH, lines #6 and #7 are freetext. Note how they have been truncated, menopaus* will pick up menopause or menopausal. Lines #8 - #10 cover periodontal disease, again MeSH and related terms. Finally, we bring the search together in the final line - #3 (terms for alendonate), and #7 (terms for menopause) and #11, terms for periodontal disease. That constitutes a comprehensive search.
The Cochrane Collaboration and the Cochrane Oral Health Group Anne Littlewood Trials Search Co-ordinator [email_address]
Well structured research question is the place to start: PICO
Once research question established, next stage is a systematic search of the literature
Makes sure all relevant studies included
Reduces the risk of bias
Ensures that others can replicate study
PICO Participants eg children with caries, smokers with periodontal disease Intervention eg antibiotics, physiotherapy, powered toothbrushes Comparison What the intervention is to be compared to: eg another intervention, placebo Outcomes eg longevity of restorations, pain reduction, quality of life
Alendronate for preventing periodontal disease in postmenopausal women
#1 Alendronate [mh:noexp]
#2 (Alendronate or biphosphonates or diphosphonates or clodronate or etidronate sodium or etidronate acid or residronate or risedronate or incadronate or tiludronate or ibandronate or medronate or pamidronate)
#3 #1 or #2
#4 Menopause [mh:noexp]
#5 (post-menopaus* or "post menopaus*" or postmenopaus*)
#6 (menopaus* or “elderly women” or osteoporo*)
#7 #4 or #5 or #6
#8 Periodontal Disease [mh:exp]
#10 ("furcation defect*" or "alveolar bone loss" or "gingival recession" or (teeth and loss) or (teeth and lost) or (teeth and lose) or (tooth and loss) or (tooth and lost) or (tooth and lose) or (tooth and mobil*) or (teeth and mobil*) or (tooth and extract*) or (dental and extract*) or (extract* and teeth))