The Cochrane Library 2011 Impact Factor and Usage Data Pack When considering the data presented below, please be aware of the following: The dataset we have used to generate impact factors for individual review groups (ISI Web of Science) is slightly different to the dataset that ISI use 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. Both ISI databases (Web of Science and Journal Citation Report) report upon the number of articles published in a year. For The Cochrane Database of Systematic Reviews (CDSR) this means all new reviews plus all updated Reviews that have a new citation record. Each individual review group faces a variety of challenges in the publication of Cochrane Reviews, and some of these may impact upon the data presented below. For example, if a CRG publishes a large number of updated Reviews with new citation records these may increase the ratio of publications to citations, thereby lowering the impact factor. 1. How the Stroke Group contributes to Cochrane Database of Systematic Reviews (CDSR): a) Each year in June Thomson Reuters publish the impact factors of all journals indexed in the ISI Journal Citation Report. b) The 2011 impact factor for CDSR is 5.912, which describes the ratio of the number of reviews published during 2009 and 2010 (1306) to the number of citations these reviews received in 2011 (7721). The 2011 CRG impact factor for Stroke Group is 6.027 (37 publications cited 223 times). A review published by the Stroke Group in 2009 or 2010 was cited, on average, 6.027 times in 2011. September, 2012 / 1
c) The top ten most cited reviews from the Stroke Group contributing to the 2011 impact factor are: CD Number Review Title Times cited in 2011 CD000213 Thrombolysis for acute ischaemic stroke 37 CD004433 Constraint-induced movement therapy for upper extremities in stroke patients 17 CD000425 Speech and language therapy for aphasia following stroke 16 CD003316 Physical fitness training for stroke patients 14 CD006787 Music therapy for acquired brain injury 9 CD006075 Overground physical therapy gait training for chronic stroke patients with mobility deficits 9 CD007231 Stem cell transplantation for ischemic stroke 8 CD004294 Rehabilitation for older people in long-term care 7 CD000255 Antithrombotic drugs for carotid artery dissection 7 CD007030 Interventions for post-stroke fatigue 7 The full list of Reviews contributing to the 2011 impact factor for the Stroke Group is provided in the accompanying Excel file. September, 2012 / 2
d) The top ten most cited reviews (2011) published in the CDSR (all CRGs) contributing to the 2011 impact factor are: Review Title Interventions for preventing falls in older people living in the community CRG Bone, Joint and Muscle Trauma Group Times Cited in 2011 141 Interventions for treating obesity in children Heart Group 79 Decision aids for people facing health treatment or screening decisions Continuing education meetings and workshops: effects on professional practice and health care outcomes Consumers and Communication Group Effective Practice and Organisation of Care Group 70 56 Methods to increase response to postal and electronic questionnaires Methodology Review Group 55 Interventions for preventing falls in older people in nursing care facilities and hospitals Exercise for depression Surgical approach to hysterectomy for benign gynaecological disease Bone, Joint and Muscle Trauma Group Depression, Anxiety and Neurosis Group Menstrual Disorders and Subfertility Group 52 45 45 Surgical management of pelvic organ prolapse in women Incontinence Group 42 School-based physical activity programs for promoting physical activity and fitness in children and adolescents aged 6-18 Metabolic and Endocrine Disorders Group 41 2. How the Stroke Group impact factor compares to that of other Cochrane Review Groups (CRGs): a) Figure 1, details the number of publications and citations contributing to the 2011 impact factor for each CRG as a percentage of the CDSR. Figure 2 shows the 2011 CRG impact factor for each CRG. Figure 3 represents a comparison between the 2011 CRG impact factor and the 2010 CRG impact factor for each CRG. It is important to remember that these figures have been calculated using datasets from ISI Web of Science and are not official impact factors. September, 2012 / 3
Figure 1: % Publications (Dark blue) and % Citations (Light blue) of CDSR for each CRG September, 2012 / 4
Figure 2: CRG impact factor for each CRG (i.e. number of cites in 2011 to reviews published by in 2009 2010, divided by the number of reviews published in 2009 2010) September, 2012 / 5
Figure 3: % CRG impact factor difference 2010-2011 for each CRG September, 2012 / 6
3. How the Stroke Group impact factor compares with that of journals publishing in the same subject: We have compared the CRG data with journals in the relevant subject categories. Sometimes the journal with the top impact factor is not directly comparable either because of the scope of the journal, or the number of reviews published in which case we have identified a journal as a possible match to the review group subject area. CRG Category (median IF) Top Journal by IF Possible match from subject Stroke Group Clinical Neurology Lancet Neurology Stroke 6.027 2.119 23.462 5.729 Please contact Gavin Stewart (gstewart@wiley.com) if you would like to see comparisons to other journals. 4. How the citation data compare to Wiley Online Library usage data: a) Each Review in CDSR, regardless of publication date, was accessed in full-text format on average 567.89 times during 2011 (5,134 articles accessed 2,915,558 times). This is a slight decrease of 3.9% on the 2010 figure of 589.96 (4,615 articles accessed 2,722,663 times). Reviews published by the Stroke Group were accessed in full-text format on average 633.11 times during 2011 (149 articles accessed 94,333 times). This is a drop of 3% on the 2010 figure of 652.65 (137 articles accessed 89,413 times). September, 2012 / 7
b) The top ten most accessed reviews from Stroke Group are: CD Number Review Title Full Text Accesses CD000213 Thrombolysis for acute ischaemic stroke 3,190 CD000425 Speech and language therapy for aphasia following stroke 3,079 CD000197 Organised inpatient (stroke unit) care for stroke 2,859 CD004433 CD003585 CD001920 Constraint-induced movement therapy for upper extremities in stroke patients Occupational therapy for patients with problems in activities of daily living after stroke Physiotherapy treatment approaches for the recovery of postural control and lower limb function following stroke 2,252 2,231 2,199 CD003316 Physical fitness training for stroke patients 2,164 CD000323 Interventions for dysphagia in acute stroke 1,950 CD008349 Virtual reality for stroke rehabilitation 1,825 CD006430 Occupational therapy for cognitive impairment in stroke patients 1,709 The access data for all Stroke Group Reviews during 2011 is provided in the accompanying Excel file. 5. How the usage of Stroke Group reviews compares to usage of reviews published by other Cochrane Review Groups: a) Figure 4, details the number of publications and full text accesses contributing to the usage figure of 567.89 for each CRG as a percentage of the CDSR. Figure 5 shows the average usage per review as accessed via Wiley Online Library during 2011 (regardless of publication date). Figure 6 shows a comparison between the 2011 usage figure and the 2010 usage figure for each CRG. September, 2012 / 8
Figure 4: % Publications (dark blue) and % Full Text Accesses (light blue) of CDSR for each CRG (in order of percentage of publications) September, 2012 / 9
Figure 5: Average number of full-text accesses during 2011 by Cochrane Review Group September, 2012 / 10
Figure 6: % average full text access difference 2010-2011 for each CRG September, 2012 / 11
Additional resources: A Frequently Asked Questions (FAQ) document is available from The Cochrane Library homepage, which describes the CDSR impact factor and contains additional information about the citation index. You can access this document here. If you have any further queries regarding the data presented in this report, please contact Gavin Stewart (gstewart@wiley.com). September 2012 / 12