NICE JOINT INFORMATION DAY 2013Prepared by: Jenny Harbour

1. “Supplementary” searching

2. Changes to the Cochrane Library interface

3. Searching Embase (or not?)

4. Finding UK information

5. And the best of the rest…

OUTLINE

“SUPPLEMENTARY” SEARCHING

• So why search multiple databases at all?

– Find articles in one database not found in another

– Compensates for different indexing in cross discipline topics

– Identifies highly cited (and therefore key) items

RESEARCH QUESTION

Do we spend too much time searching databases and not enough time on supplementary searching?

“A more selective approach to database searching would suffice in most cases…… searching non-database sources….. does appear to be a productive way of identifying further studies”1. Royle P, Waugh N. Literature searching for clinical and cost effectiveness studies used in health technology assessment reports carried out for the National Institute for Clinical Excellence appraisal system. Health Technol Assess. 2003;7(34):iii,ix-x,1-51.

DIMINISHING RETURNS

• Literature survey and empirical study

• Literature examining Medline coverage & database overlap:

– Medline alone found 16-100% of included references

– Studies missed in Medline were often indexed but not retrieved

• Results from empirical study:

– 1,234 references identified from 50 systematic reviews

– 85.82% indexed in Medline

– Medline coverage varies between subject areas

– If use a very effective search strategy, Medline finds 80% or more of included studies

BOOTH STUDY

If yield in Medline <80% check why and refine strategy

TRIPLE PLUS

3 key databases (journal articles)

Specialist sources

(non-journal literature)

Google Scholar &

supplementary searching

TRIPLE PLUS

COCHRANE LIBRARY CHANGES

• Shorthand for combining lines

– Enclose ranges in { } e.g. {and #1-#4}

– Cannot use NOT operator with this function

• Direct keying of MeSH terms

– Must be placed in [ ] e.g. [mh cholesteatoma]

– Use ^ before MeSH heading to turn OFF explosion e.g. [mh ^cholesteotoma]

– Qualifiers (sub-headings) must be entered in CAPITALS e.g. [mh cholesteatoma/BL,CO]

– Phrases must be in quotes e.g. [mh “cholesteatoma, middle ear”]

SHORTHAND AND MESH

• Finding search errors

– Common errors automatically identified in red text

• New search help page for guidance

• “Highlight orphan lines”

– Must be done AFTER you have completed search

– Search Manager screen only

FINDING ERRORS

• Append a search

– Adds saved search to end of current search

– Re-usable search elements

• Share a search

– Recipient can run your search and save to their own Cochrane account

– Send via email or copy link for document/webpage options

• Get help

– Available from Cochrane library homepage

– Click New Search Tools icon

SAVED SEARCHES

EMBASE OR NOT?

• What was already known:

– NICE and Cochrane recommend thesaurus terms and

free-text

– Approx. 80,000 trials in Embase not indexed as RCT in

Medline

– Embase searches generally less precise than Medline

– Focusing Emtree terms in drug trial searches

maintained ~99% sensitivity whilst reducing number

retrieved by ~50%

LITERATURE ON USING EMBASE

• Research question: can we search Embase without using EMTREE terms?

• Retrospectively analysed searches and included studies from 8 guidelines

– How many included studies came exclusively from Embase?

– Are ‘exclusive to Embase’ studies retrieved without EMTREE terms?

PROJECT 1 METHODS

• Of 190 included studies, 15 (7.9%) were exclusive to Embase

• Searching without EMTREE terms found 7 of the 15 exclusive studies

• Embase delivers small but significant unique contribution?

PROJECT 1 RESULTS

0102030405060708090

100

Number of cited ref-erences that were "exclus-ively found in Embase"References found in other sources

• Research question: can we be more efficient by searching fewer databases?

• What this study did:

– Retrospectively analysed unique results from core databases (Could searching be restricted to Medline?)

– Assessed the performance of NICE IP searches (If studies are indexed in Medline, why aren’t they retrieved?)

PROJECT 2 METHODS

PROJECT 2 RESULTS

92% studies indexed in Medline

93% studies indexed in Embase

• 68% of Medline strategies retrieved 100% of included studies indexed in Medline

• 24 studies indexed in core resources but not retrieved

• So can we restrict searching to Medline? No

– Deeper indexing in Embase useful for novel topics

– Studies picked up sooner in Embase

PROJECT 2 RESULTS

FINDING UK INFORMATION

• Choosing the wrong resources can bias reviews

• Rapid reviews focus on UK…

• …but main databases used are American

WHY SEARCH UK DATABASES?

“We do not need more information but different information: information which challenges that

which is commonly known or believed”

Study to explore usefulness of UK databases e.g. BNI, HEED etc• Searches on databases titles to identify evidence on

databases• Interview (chats?) with information specialists

‘INTERVIEW’ COMMENTS

FINDABILITY

Pubmed + UK

..PROBLEMS ARE NOT UK DATABASE PROBLEMS BUT SMALL DATABASE PROBLEMS

The lack of export function drives me nuts..

Better platforms i.e. OVID

AND THE BEST OF THE REST…

• Objectively derived search strategies

– Covered in a previous workshop

– Transfers methods for filter development to topic searches

– Search terms identified based on frequency analysis of key references

– Removes requirement for subject knowledge

– 95.69% of relevant references found by traditional search identified by objective search

– Difficult to apply to non-drug interventions

OBJECTIVE SEARCH STRATEGIES

• Citation searching:

– Comparison of citation searching in Google Scholar (GS) and Web of Science (WOS)

– Of 39 included studies, 6 retrieved by GS but not WOS, 3 retrieved by WOS but not GS

– All 8 high importance papers found by both GS and WOS

– Study conclusions would not have been changed by using one rather than other

– WOS were cheapest to administer and sift

CITATION SEARCHING

ANY FINAL QUESTIONS

EVALUATION

Please can you all complete a workshop evaluation form and hand it in before you leave?