European collaboration to identify reports of controlled trials in general and specialized health care journals published in Western Europe Gerd Antes German Cochrane Centre, Freiburg Anne Lusher and Carol Lefebvre UK Cochrane Centre, Oxford, UK

Biomed Projects 1995 – 1998 Biomed 1 (General health care journals) 1998 – 2001 Biomed 2 (Special health care journals)

Transfer of Medical Research into Practice Information about medical interventions Clinical studies (controlled / randomized,..) Epidemiological (observational -) studies.... Evidence Use Evidence Production Practicing physicians Patients Authorities, health insurances, institutions Clinical research ?

Information Paths Medline (US National Library of Health, NLM) Embase (Elsevier) Cochrane Collaboration Controlled Trials Register (CCTR) Others Not in databases

Barriers to trial identification Scattered across the health care literature Lack of appropriate indexing terms (Dickersin et al, BMJ 1994;309: ) Inconsistency in applying available terms (Lefebvre et al, conference National Institutes of Health, 1993) (Jadad et al, Pain 1996;66:239-46) Incomplete descriptions of research methodology by authors

Barriers to trial identification (2) Journals not indexed in databases (Egger et al, BMJ 1998;316:61-6) Exclusion of specific sections of journals (e.g. conference abstracts) from the indexing process (Scherer et al, Cochrane Database of Methodology Reviews, 2001) Journals published in languages other than English (Egger et al, Lancet 1997;350:326-9)

AIM To identify reports of controlled trials by searching, by hand, specialized health care journals published in Western Europe OBJECTIVE To ensure that all trial reports identified in these journals are made accessible through The Cochrane Controlled Trials Register (CCTR), published in The Cochrane Library

METHODS Identifying the journals to search Health care journals published in Western Europe were ranked according to likely yield of reports of controlled trials Each participant identified journals locally which were not indexed in MEDLINE or EMBASE Collaborative Review Groups were invited to suggest high yield journals in their subject areas published in Western Europe

METHODS Handsearching All articles, editorials, letters, conference abstracts, news items in each journal were examined and coded as RCT (reports of randomized controlled trials) or CCT (reports of quasi-randomized or possibly randomized trials) Quality control checks of the handsearch results were carried out

METHODS Making the trial reports accessible Titles of trial reports identified in languages other than English were translated All trial reports identified were submitted for inclusion in CCTR Trial reports in MEDLINE indexed without appropriate Publication Type terms were sent for re-tagging in MEDLINE

Figure 1

Number of reports of controlled trials identified and number of ‘journal years’ searched per participant

Number of reports of controlled trials identified per participant, which were not previously easily identifiable in MEDLINE as randomized trials – ‘added value’ of the project

Number of reports of randomized trials identified in this project and their accessibility in MEDLINE

Number of trial reports identified in languages other than English

Results (July June 2001, Biomed 2 ) 340 journals searched (published in 15 European countries in 7 languages) 5,687 ‘journal years’ searched 36,981 citations of trial reports in a single source 8,792 trial reports re-tagged in MEDLINE with Publication Type terms All sections of journals searched including those containing conference abstracts 11,959 trial reports identified in languages other than English

Number of reports of controlled trials identified by the BIOMED handsearching projects and their accessibility in MEDLINE

Number of reports of controlled trials identified and number of ‘journal years’ searched by each Participant – BIOMED General and Specialized Health Care Journals handsearching projects

Implications for methodological research This project provides a large dataset of: Abstracts of reports of randomized trials Trial reports in journals not indexed in databases Trial reports in languages other than English

Indirect added value Major input to the development and growth of the Cochrane Collaboration ( volunteers) Starting point for establishing Cochrane Centres (e. g. the German Centre) CC Trials Register (CCTR) now citations Close cooperation with publishers Motivation for searching trials in other regions

Some barriers remain… LONGER TERM SOLUTION: Prospective registration of all randomized trials Tagging trials with the International Standard Randomised Controlled Trial Number (ISRCTN) metaRegister of Controlled Trials (