Cochrane contributors are smiling all over the world with news of the Cochrane Database of Systematic Reviews’ (CDSR) impact factor (IF) rising again in 2010 to 6.186. The CDSR’s IF has risen an average of 10 per cent over the past four years.

Each year in June, Thompson Reuters publishes the impact factors of all journals indexed in the ISI (Institute for Scientific Information) Journal Citation Report. The CDSR’s impact factor describes the ratio of the number of reviews published during 2008 and 2009 (1,128) to the number of citations these reviews received in 2010 (6,978). The CDSR’s IF increased by 9.4 per cent from 5.653 in 2009. A review published in the CDSR in 2008 or 2009 was cited, on average, 6.186 times in 2010. Of significance is the fact that the CDSR is now ranked in the top 10 (of 151) in the Medicine, General & Internal journal category.

Each Review in the CDSR, regardless of publication date, was accessed in full-text format on average 589.96 times during 2010 (4,615 articles accessed 2,722,663 times). This is an increase of 6.4 per cent on the 2009 figure of 554.60 (4524 articles accessed 2,508,999 times).

As always, the six Cochrane Review Groups which are members of Cochrane Canada continue to do well in the impact factor rankings.

• The Musculoskeletal Group (CMSG) has an impact factor of 7.310 for 2010, up from 6.409 in 2009, placing it in the top ten IFs calculated for the 52 Cochrane Review Groups. Notably, the CMSG considerably outranked other journals it was compared to in this category:  Orthopedics 1.164, Osteoarthritis and Cartilage, 3.953, and BMC Musculoskeletal disorders 1.941.
• The Back Group saw an increase from 5.682 to 6.000 (13 publications cited 78 times). Reviews published by the Back Group were accessed in full-text format on average 1107.89 times during 2010 (54 articles accessed 59,826 times). This is an increase of six per cent on the 2009 figure of 1038.31 (54 articles accessed 56,069 times).
• The Upper Gastrointestinal and Pancreatic Diseases (UGPD) Group saw an increase in its Impact Factor calculation of 2.889, up from 2.556 in 2009. The UGPD group’s full-text accesses increased by 29 percent to an average of 639.29 during 2010 (49 articles accessed 31,325 times). This is the second highest increase in full-text accesses.
• The Effective Practice and Organisation of Care (EPOC) Group’s impact factor of 6.880 put it in the top fifteen IFs of the 52 Cochrane Review Groups. Full-text accesses of EPOC’s reviews averaged 1,277.04 during 2010 (71 articles accessed 90,670 times), an increase of 21 per cent on the 2009 figure of 1003.88. The top accessed review from EPOC was ‘Discharge planning from hospital to home’ with 6,142 accesses.
• The impact factor for the Inflammatory Bowel Disease and Functional Bowel Disorders (IBD/FBD) Group is 6.182 (22 publications cited 136 times) and is in the top 20 IFs of the Cochrane Review Groups. The IBD/FBD impact factor compares favourably to other journals in its category: Gastroenterology and Hepatology 2.240, Gastroenterology 12.032, and Inflammatory Bowel Diseases 4.613.
• The Hypertension (HTN) Group received an impact factor of 4.750 (16 publications cited 76 times). Reviews published by HTN were accessed in full-text on average 829.95 times during 2010 (37 articles accessed 30,708 times), an increase of 11 per cent on the 2009 figure of 735.32 (37 articles accessed 27,207 times).

The dataset Wiley-Blackwell used to generate impact factors for individual review groups (ISI Web of Science) is slightly different to the dataset ISI uses to calculate the impact factors of journals (the Journal Citation Report). Individual Cochrane Review Group (CRG) impact factor data, therefore, should not be quoted as “official” impact factors, but can be used within the Collaboration. The IFs, as seen above, are used only to facilitate comparison between groups and similar journals.