Received October 4, 2004 Address for correspondence: MING-YUEH TSAY
Graduate Institute of Library, Information and Archival Studies National Chengchi University, 64, Sec.2, Chinan Rd., Wenshan Section Taipei, 116, Taiwan, Republic of China
E-mail: mytsay@nccu.edu.tw
Journals of general & internal medicine and surgery:
An analysis and comparison of citation
MING-YUEH TSAY,a YI-LING CHENb
a Graduate Institute of Library, Information and Archival Studies, National Chengchi University,
Taipei (Taiwan)
b Chi Mei Foundation Hospital Library, Liou Ying (Taiwan)
The purpose of this study is to analyze and compare journal citation data, from Journal Citation Reports on the Web 2000, of general and internal medicine and surgery. The source items and five kinds of citation data, i.e. citation counts, impact factor, immediacy index, citing half-life and cited half-life are examined and the correlation between each of the fifteen pairs of citation data is determined based on the Pearson correlation tests. The Fisher’s Z-transform was employed to test the significant difference between the Pearson correlation coefficient for each pair of citation data of these two subject areas. The following results of this work reveal: the frequently published journals are cited more frequently and also with high impact factor and immediacy index, in addition, they are usually accompanied with short citing half-life (i.e., usually cite current literature). The impact factor and immediacy index has significant correlation with citation counts. A significant correlation also exists between impact factor and immediacy index. However there is no correlation between cited half-life and other citation data, except citing half-life. For journals of general and internal medicine and surgical medicine, there are no significant difference of the Pearson correlation coefficient for the following pair of citation data: source items and citation counts, source items and impact factor, source items and citing half-life, citation counts and citing half-life, impact factor and citing half-life, immediacy index and citing half-life, and cited half-life and citing half-life.
Introduction
Many factors, such as journal citation analysis, journal productivity, and evaluation by subject experts, may be employed to judge the value of journals. Each factor, or many interacting factors, can form the basis for journal selection or deselection in a library. A policy based on a study of journal productivity, for instance, will result in a collection for which the number of papers published by journals in a particular subject field is the major criterion for inclusion. On the other hand, citation analyses have frequently been used to produce lists of journals ranked by number of citations received.
It has often been stated or implied that such lists form a valid guide for selection of library materials. Both types of studies can serve as a guide to library acquisition, but a citation analysis can further show how knowledge is changing, or becoming obsolescent, and help optimize an information retrieval system.1 Moreover, citation
analysis is thought to be important in academic life and in the universities’ research assessment exercise in many institutions. Obsolescence is another major focus of the evaluation of journal value. The essential question to be answered by a study of obsolescence is how long will a publication continue to be used after it has been published? The rate of obsolescence can be determined by the cited half-life or citing half-life of a journal.
It is not known, however, whether the most productive journals in a particular subject field are also those that have the most citations or the highest impact factor. It is also not known whether the most productive journals are also those that have the longest cited half-life and citing half-life. The objective of the present study is to investigate the relationship and difference between the productivity (source items) of journals and their citations, in terms of citation counts, impact factor, immediacy index, cited half-life and citing half-life in the domain of general and internal medicine and surgical medicine. Journal citation data were drawn from Journal Citation Reports on the Web 2000. This study also investigates the relationship and difference between each pair of five kinds of citation data, i.e. citation counts, impact factor, immediacy index, citing half-life and cited half-life for journals of these two medical subjects.
Literature review
As the studies in the literature demonstrated, one obvious criteria for the evaluation of journals is that of productivity, which can be expressed as number of papers published by a journal in a specific subject field during a particular period of time. Other common measures of journal value are citation rate, impact factor and the rate of obsolescence. There are only a few studies investigating the relationship between journal productivity and journal value though separate studies in both are quite abundant. For example, using the literature of dye laser, Magyar,2 found that 60% of the
articles most cited appear in the most productive journals of top Bradford distribution nucleus zone. Boyce and Pollens,3 using citation as a measure of quality, they found a
strong correlation between productivity and total number of citations. Nevertheless, no significant correlation exists between productivity and either “impact factor” (number of citations earned per paper published) or “quality weight” (a type of impact factor but restricted to the papers contributed by these journals to the sub-field). Egghe and Rousseau4 clarified that the slop of the regression line of the impact as a function of the
number of publications is positive if and only if the global impact, i.e. the impact of the set of all journals under consideration, is larger than the average impact of all journals.
Rousseau and Van Hooydonk5 also show that there exists a direct linear relation
between journal production and impact factor. They observed that the more articles a normal journal publishes, the larger its impact factor. When considering disciplines, among 12 science, technology and health sciences areas, mathematics and chemistry seem to be large-scale exceptions. Cho et al.6 studied the value of infectious disease
journals by using the JCR. The assessed journals are ranked according to their 1995 impact factor, and their JCR ranks according to number of citations. They found that overall, the journals with the highest rankings by impact factor had high number of citations. Jemec7 conducted a detailed study of dermatological journals listed in the JCR
1991–2000 and found a significant linear correlation between the number of journals in a given field and the top impact factor of that field. Studying the trend for dermatological journals 1991 to 2000 a similar pattern was found. Significant correlations were also found between total number of journals and mean impact factor, between the total number of journals and the top impact factor and between the mean and the top impact factor. Tomer8 has shown that journals with high impact factor also
tend to have high immediacy indexes.
There are also some studies examining the relationship between journal productivity and obsolescence. De Queiroz and Lancaster9 addressed the question of how the journal
productivity and obsolescence characteristics of a literature change over time. They observed that as thermoluminescent dosimetry literature grew it became increasingly scattered in terms of the number of contributing journals and that the rate, in terms of median citation age, of obsolescence decrease. Wallace10 examined the relationship
between journal productivity and journal obsolescence. After conducting a statistical test, he found that “highly productive journals did tend to have low journal median citation ages, and that high journal median citation ages were always associated with journals that were unproductive in terms of the number of references to those journals in the database.” Tsay and Ma11 investigated the relationship between journals’
productivity and their citations in the field of semiconductors. The results of the study showed that there is a significant correlation between journal productivity and citation frequency and between journal productivity and impact factor. However, there are no associations between journal productivity and cited half-life and between journal productivity and citing half-life.
The above review indicates that none of these previous studies can be considered truly conclusive, and conflicting results have been found. It has not been demonstrated that articles contributed to some subject area by the journals less productive in that field are necessarily of lower value, no matter whether value is measured by citation counts, impact factor or rate of obsolescence, than those appearing in the highly productive journals. Therefore, further studies that consider other parameters, such as cited half-lives, citing half-half-lives, immediacy index, etc. with relation to each other is needed.
Methodology
In this study, the citation data were drawn from the JCR Web 2000. The database, published by the Institute for Scientific Information, is an essential, comprehensive, and unique resource tool for journal evaluation, using citation data drawn from over 8,400 scholarly and technical journals worldwide.12 The JCR is the only source of citation
data on journals, and shows the relationship between citing and cited journals in a clear, easy-to-use framework.
JCR provides a listing of journals ranked by citation data, such as impact factor, citing and cited half-life, etc., within category. Specific descriptions of each of several citation parameters are given in the database. Six of these parameters – the source items, the citation counts, the impact factor, the immediacy index, the cited half-life, and the citing half-life – are examined and compared in this study. Pearson correlations from each pair of citation data were calculated to assess the significant relationship between each of the 15 pairs of these citation data. The Fisher’s Z-transform was used to test the significant difference between the Pearson correlation coefficient for each pair of citation data of two subject areas. In this study, general and internal medicine covers resources on medical specialties such as general medicine, family medicine, internal medicine, clinical physiology, pain management, and military and hospital medicine. Surgery covers resources on general surgical topics including the different types of surgery (cardiovascular, neurosurgery, orthopedic, pediatric, or vascular); allied disciplines of surgery (surgical oncology, pathology, or radiology); and surgical techniques (arthroscopy, microscopy, or endoscopy).13
Definition of terms
The following definitions for terms of citation data were drawn from JCR Web 2000.14
Source Items and Citation Counts
Source Items and Citation Counts are important indicators of how frequently current researchers are using individual journals. Source Items, also named as journal productivity, show the number of articles published in a journal in a particular year or years. Editorials, letters, news items, and meeting abstracts are not included in source items because they are not generally cited. Citation Counts indicate the total number of times that each journal has been cited by all journals included in the ISI database within the current product year.
Impact Factor
The journal impact factor is “a measure of the frequency with which the ‘average article’ in a journal has been cited in a particular year.” The JCR impact factor is calculated by dividing the number of current citations to articles published in the two previous years by the total number of articles published in the two previous years. Immediacy Index
The journal immediacy index is a measure of how quickly the “average article” in a journal is cited. It is calculated by dividing the number of citations to articles published in a given year by the number of articles published in that year. It will tell one how often articles published in a journal are cited within the same year.
Cited Half-life
The cited half-life is the number of publication years from the current year which account for 50% of current citations received. They basically reflect the timeliness with which articles in a journal are citing other articles, and are cited by other articles. This figure can help one evaluate the age of the majority of cited articles published in a journal.
Citing Half-life
The citing half-life is the number of publication years from the current year that account for 50% of the current citations published by a journal in its article references. This figure can help one evaluate the age of the majority of articles referenced by a journal.
Results and discussion
The data of source items, citation counts, impact factor, immediacy index, cited half-life and citing half-life were obtained from JCR Web 2000 by the title-by-title search and are listed in Appendix 1 and Appendix 2. The Pearson correlation was applied to determine the correlation coefficient between each pair of citation data. With the source items and five citation indicators under consideration, there are fifteen pairs for conducting the test. Table 1 shows the Pearson correlation coefficients of general and internal medicine journals for the fifteen pairs of citation indicators together with the p-value and the number of journals for each study pair. Table 1 indicates that for
p<0.05 significant correlation exists between source items and citation counts, between source items and impact factor, between source items and immediacy index, between citation count and impact factor, between citation count and immediacy index, between impact factor and immediacy index, between cited half-life and citing half-life.
Based on the “success-breeds-success” phenomenon15 one could expect that, the
more articles a journal publishes, the higher its visibility, the higher its chance to be cited, and hence, the higher its impact factor and immediacy index. In contrast, journals with lower productivity receive fewer citations and a lower impact factor. Moreover, it should be noted that the citation counts, impact factor ad immediacy index involve the same basic citation data. It is not surprised to note that significant correlations exist between productivity and these three citation variables, respectively.
Interestingly, the coefficient between citation counts and impact factor, and between citation counts and immediacy index is quite large. This can be understood that either impact factor or immediacy index is based on citation counts in certain period. The impact factor and immediacy index also has strong association since both two parameters are computed on the basis of total citation that each journal receives during one or two years.
A significant negative correlation exists between citing half-life and source items, citation count, impact factor and immediacy index. This suggests that a journal in general and internal medicine with a large source items, citation counts, impact factor or immediacy index tends to cite newly published articles. On the other hand, the positive correlation between citing half-life and cited half-life indicates that a general and internal medicine journal with a short cited half-life tends to cite newly published articles and vise versa. Table 1 also illustrates that there is no significant correlation between cited half-life and other citation indicator except the citing half-life. This suggests that a general and internal medicine journal with larger source items, citation counts, impact factor, immediacy index may not have longer cited half-life.
A Pearson correlation test was also conducted for surgical medicine journals for each pair of citation indicator, as shown in Table 2. The table indicates that the test results for surgical medicine journals are quite similar to that for general and internal medicine. However, there is a significant correlation between cited half-life and citation counts for surgical medicine journals in contrast to that for general and internal medicine journals. Moreover, the correlation coefficient for each pair is also different for journals in surgical medicine and general and internal medicine. In particular, the correlation coefficient between citation counts and impact factor, between citation counts and immediacy index, and between impact factor and immediacy index is much larger for general and internal medicine journals than that for surgical medicine journals.
Table 1. Pearson correlation coefficient and P value between citation indicators of general and internal medicine journals
Source Item Citation Count Impact Factor Immediacy Index Cited Half-Life 0.663** Citation Count 0.000 No. of journals 103 0.424** 0.883** Impact Factor 0.000 0.000 No. of journals 103 105 0.585** 0.911** 0.924** Immediacy Index 0.000 0.000 0.000 No. of journals 100 100 100 –0.033 0.044 –0.011 –0.042 Cited Half-Life 0.749 0.662 0.912 0.688 No. of journals 97 99 99 94 –0.361** –0.268** –0.252* –0.348** 0.317** Citing Half-Life 0.000 0.008 0.012 0.000 0.002 No. of journals 98 98 98 98 93 * =0.05, ** =0.01
Table 2. Pearson correlation coefficient and P value between citation indicators of surgical medicine journals Source Items Citation Counts Impact Factor Immediacy Index Cited Half-Life 0.696** Citation Count 0.000 No. of journals 135 0.353** 0.687** Impact Factor 0.000 0.000 No. of journals 134 135 0.279** 0.523** 0.811** Immediacy Index 0.001 0.000 0.000 No. of journals 134 134 133 0.063 0.358** –0.048 –0.084 Cited Half-Life 0.479 0.000 0.595 0.351 No. of journals 127 127 127 126 –0.208* –0.208* –0.461** –0.461** 0.363** Citing Half-Life 0.016 0.016 0.000 0.000 0.000 No. of journals 134 134 133 134 126 * =0.05, ** =0.01
To further clarify the strength of the correlation between each pair for journals in both fields of medicine under study, a Fisher test is conducted. Let
Z=0.5log[(1+ )/(1- )]
be the Fisher’s Z-transformation of the sample correlation coefficients . Suppose we have a sample of size n1from one population and a sample of size n2 from a second population. Under the null hypothesis H: 1= 2, Z1-Z2 has normal distribution with mean 0 and variance an asymptotic 1/(n1-3)+1/(n2-3). A critical region of size 5% is therefore16
|Z1-Z2|/[1/(n1-3)+1/(n2-3)]0.5 >1.96
Table 3 illustrates the pair-wise difference between correlation for citation data with significant correlation for the two samples under study, i.e., the general and internal medicine journals and surgical medicine journals. The table clearly indicates that there is no significant difference for the two samples in the correlation between source items and citation counts, between source items and impact factor, between source items and citing half-life, between citation counts and citing half-life, between impact factor and citing life, between immediacy index and citing life, and between cited half-life and citing half-half-life. However, the correlation between source items and immediacy index, between citation counts and impact factor, between citation counts and immediacy index, and between impact factor and immediacy index for the general and internal medicine journals is significantly larger than that for the surgical medicine journals. The reason why the correlation for these four pairs for general and internal medicine journals is stronger than that for surgical medicine journals is not clear. Further study is needed.
Table 3. Pair-wise difference between correlation for citation data
Source Items Citation Counts Impact Factor Immediacy Index Cited Half-Life Citation Counts 0.463
Impact Factor 0.630 4.15*
Immediacy Index 2.86* 7.11* 3.62*
Citing Half-Life 1.23 0.472 1.79 1.00 0.375
*Pair-wise difference between correlation >1.96, the null hypothesis is rejected
Conclusions
The present study examines the relationship and difference between the citation data for journals of general and internal medicine and surgical medicine. The results of Pearson correlation test reveal that the frequently published journals are cited more frequently and also with high impact factor and immediacy index, in addition, they are usually accompanied with short citing half-life (usually cite current literature). However there is no correlation between cited half-life and other citation data, except citation
counts and citing half-life. This suggests that there is really no association between productivity and cited half-life. This indicates that a more productive journal may not be cited frequently for long periods.
The results of Fisher test reveal that for journals of general and internal medicine and surgical medicine, there is no significant difference for the two samples in the correlation between source items and citation counts, between source items and impact factor, between source items and citing half-life, between citation counts and citing half-life, between impact factor and citing half-life, between immediacy index and citing half-life, and between cited half-life and citing half-life. However, the correlation between source items and immediacy index, between citation counts and impact factor, between citation counts and immediacy index, and between impact factor and immediacy index for the general and internal medicine journals is significantly larger than that for the surgical medicine journals.
*
This work was supported by grant NSC 90-2413-H-032-009 from the National Science Council, Taiwan, R.O.C.
References
1. M. B. LINE, A. SANDISON, Obsolescence and changes in the use of literature with time. Journal of
Documentation, 30 (3) (1975) 283–350.
2. G. MAGYAR, Bibliometric analysis of a new research sub-field. Journal of Documentation, (1974) 32. 3. B. R. BOYCE, J. S. POLLENS, Citation-based impact measures and Bradfordian criteria. Collection
Management, 4 (1982) 29.
4. L. EGGHE, R. ROUSSEAU, Average and global impact of a set of journals, Scientometrics, 36 (1) (1996) 97–107. 5. R. ROUSSEAU, G. VAN HOOYDONK, Journal production and journal impact factors, Journal of the
American Society for Information Science, 47 (10) (1996) 775–780.
6. J. E. CHO, C. T. CHO, J. M. BELMONT, Learning to assess the value of infectious disease journals. Journal of the Microbiological Immunology Infectious, 31 (1998) 1–4.
7. G. B. E. JEMEC, Impact factors of dermatological journals for 1991–2000.
(http://www.biomedcentral.com/1471-5945/1/7) (BMC Dematology, 1:7, November ,2001).
8. C. TOMER, A statistical assessment of two measures of citation: The impact factor and the immediacy
index. Information Processing and Management, 22 (1986) 251–258.
9. G. G. DE QUEIROZ, F. W. LANCASTER, Growth, dispersion and obsolescence of the literature – A case study from thermoluminescent dosimetry. Journal of Research Communication Studies, 2 (1981) 203–217. 10. D. P. WALLACE, The Relationship between Journal Productivity and Obsolescence in a Subject
Literature. Ph.D. diss., University of Illinois at Urbana-Champaign, 1985, p. iii.
11. M. Y. TSAY, S. S. MA, The nature and relationship between the productivity of journals and their
citations in semiconductor literature. Scientometrics, 56 (2) (2003) 201–222. 12. <http://isil.jcrweb.com> (2003/08/24).
13. <http://sunweb.isinet.com/isi/journals/scope/scope_scie.html> 14. <http://isi1.jcrweb.com/help/hjcr_a1.htm>(20 March 2002).
15. D. DE SOLLA PRICE, A general theory of bibliometric and other cumulative advantage processes, Journal of the American Society for Information Science, 27 (1976) 292–306.
16. T. W. ANDERSON, An Introduction to Multivariable Statistical Analysis, 2nd ed. New York : Wiley,
Appendix 1
Journals in general & internal medicine
No Title SourceItems CitationCount ImpactFactor ImmediacyIndex Cited Half-Life Half-LifeCiting 1 Acta Clinica Belgica 32 209 0.381 0.000 5.3 6.1 2 Acta Medica Austriaca 47 131 0.158 0.000 5.5 5.5 3 American Family Physician 199 1552 0.888 0.518 4.7 5.2 4 American Journal of Chinese Medicine 48 314 0.583 0.021 7.2 9.8 5 American Journal of Managed Care 169 399 0.642 0.160 2.7 4.1 6 American Journal of Medicine 192 20938 5.960 0.948 >10.0 5.6 7 American Journal of Preventive Medicine 147 2051 2.192 1.619 4.4 5.5 8 American Journal of the Medical Sciences 139 3022 1.520 0.115 >10.0 8.2 9 Amyloid – International Journal of Experimentaland Clinical Investigation 41 427 2.957 0.073 3.1 6.3 10 Annales de Medecine Interne 139 569 0.420 0.029 7.1 6.7 11 Annals of Internal Medicine 210 35912 9.833 2.405 8.2 5.4 12 Annals of Medicine 88 1849 2.794 0.216 5.0 5.3 13 Annals of Saudi Medicine 45 217 0.097 0.000 6.9 8.6 14 Annual Review of Medicine 33 2712 9.891 1.333 5.4 5.5 15 Archives of Family Medicine 147 1252 2.262 0.469 4.5 6.5 16 Archives of Internal Medicine 348 21329 6.055 1.241 7.2 6.4 17 Australian and New Zealand Journal of Medicine 124 1310 0.413 0.169 7.9 5.1 18 Aviation Space and Environmental Medicine 184 2248 0.658 0.103 9.2 9.9 19 British Journal of General Practice 147 2197 1.627 0.837 4.7 5.3 20 British Medical Bulletin 65 2274 1.869 0.077 7.4 5.1 21 British Medical Journal 612 51530 5.331 2.928 6.9 3.7 22 Bulletin de l’ Academie Nationale de Medecine 100 328 0.195 0.060 5.4 4.9 23 Canadian Family Physician 168 606 0.407 0.226 4.3 5.7 24 Canadian Medical Association Journal 190 4932 2.352 1.489 7.2 4.8 25 Chinese Medical Journal 284 752 0.107 0.000 7.9 6.4 26 Cleveland Clinic Journal of Medicine 79 552 0.827 0.241 8.1 4.7 27 Current Medical Research and Opinion 27 376 1.000 0.333 >10.0 5.5 28 Danish Medical Bulletin 22 634 0.914 0.045 9.9 9.3 29 Deutsche Medizinische Wochenschrift 315 2267 0.788 0.203 8.8 5.3 30 DM Disease – A – Month 26 148 0.548 0.077 7.4 5.5 31 East African Medical Journal 130 829 0.199 0.108 6.9 >10.0 32 Ethiopian Medical Journal 30 157 0.149 0.000 9.1 9.5 33 European Journal of Clinical Investigation 143 3952 2.071 0.322 6.7 6.4 34 Family Practice 106 1174 1.078 0.113 5.9 5.9 35 Harvey Lectures 7 166 0.154 0.000 >10.0 n.a. 36 Hospital Medicine 181 170 0.348 0.138 2.1 4.8 37 Hospital Practice 97 543 0.412 0.062 7.2 3.7 38 Indian Journal of Medical Research 67 966 0.383 0.045 >10.0 9.4 39 Internal Medicine 223 1086 0.643 0.265 4.5 7.8 40 International Journal of Clinical Practice 180 289 0.579 0.106 2.2 6.0 41 Internist 158 352 0.277 0.057 4.6 4.7 42 Irish Journal of Medical Science 33 348 0.353 0.000 7.4 6.9 43 Irish Medical Journal 6 189 0.280 0.167 7.0 5.8 44 Israel Medical Association Journal 231 4 0.027 0.009 n.a. 6.5 45 JAMA – Journal of the American MedicalAssociation 377 69197 15.402 4.523 6.4 4.4 46 Japanese Journal of Medical Science & Biology 0 311 0.444 n.a. >10.0 n.a. 47 Journal of Family Practice 96 3009 2.851 0.698 6.5 6.4 48 Journal of General Internal Medicine 111 3031 2.421 0.784 5.4 6.1 49 Journal of Internal Medicine 151 3553 2.273 0.411 6.1 6.3 50 Journal of Investigative Medicine 44 775 2.255 0.364 3.9 7.5 51 Journal of Laboratory and Clinical Medicine 112 6795 1.978 0.295 >10.0 6.9 52 Journal of Pain and Symptom Management 111 1955 1.837 0.171 5.3 6.8 53 Journal of the Formosan Medical Association 161 750 0.353 0.031 6.3 8.5 54 Journal of the National Medical Association n.a. 730 0.555 n.a. 7.5 n.a.
Appendix 1 (continued)
No Title SourceItems CitationCount ImpactFactor ImmediacyIndex Cited Half-Life Half-LifeCiting 55 Journal of the Royal College of Physicians ofLondon 85 686 0.759 0.341 5.3 4.6 56 Journal of the Royal Society of Medicine 169 1503 0.270 0.148 8.5 7.2 57 Journal of Urban Health-Bulletin of the New YorkAcademy of Medicine 55 46 0.345 0.127 n.a. 4.4 58 Journal of Womens Health 0 468 1.395 n.a. 3.2 n.a. 59 Journal of Womens Health & Gender-BasedMedicine 111 41 0.395 0.054 n.a. 6.9 60 Lancet 821 113804 10.232 3.153 6.9 4.0 61 Mayo Clinic Proceedings 169 5728 2.242 0.444 8.8 5.9 62 Medical Clinics of North America 80 2047 1.486 0.412 8.4 5.3 63 Medical Journal of Australia 246 5722 1.928 0.919 8.0 3.8 64 Medical Principles and Practice 27 31 0.097 0.000 n.a. 7.5 65 Medical Problems of Performing Artists 25 130 0.397 0.080 8.2 9.2 66 Medicina Clinica 285 1628 0.750 0.365 4.7 4.9 67 Medicina Dello Sport 25 121 0.164 0.040 >10.0 >10.0 68 Medicina-Buenos Aires 159 371 0.345 0.069 5.4 5.8 69 Medicine 34 4454 4.623 0.382 >10.0 8.6 70 Medizinische Klinik 142 593 0.390 0.056 6.5 6.3 71 Medizinische Welt 105 228 0.061 0.010 >10.0 5.5 72 Military Medicine 226 1204 0.512 0.071 7.0 7.7 73 Mount Sinai Journal of Medicine 59 536 0.628 0.254 9.1 >10.0 74 National Medical Journal of India 39 140 0.333 0.359 4.4 5.7 75 Netherlands Journal of Medicine 68 590 0.721 0.132 5.8 6.3 76 New England Journal of Medicine 379 135613 29.512 5.821 7.1 5.1 77 New Zealand Medical Journal 131 1963 1.202 0.527 7.4 5.7 78 Novartis Foundation Symposium n.a. 218 1.239 n.a. 1.9 n.a. 79 Palliative Medicine 64 648 1.989 0.188 n.a. n.a. 80 Panminerva Medica 41 110 0.169 0.000 5.3 9.0 81 Postgraduate Medical Journal 244 2515 0.339 0.057 >10.0 7.7 82 Postgraduate Medicine 180 1350 0.722 0.106 7.6 4.5 83 Presse Medicale 381 2011 0.441 0.087 7.4 5.7 84 Preventive Medicine 163 3316 1.557 0.252 6.9 6.8 85 Primary Care 56 314 0.720 0.000 5.9 5.4 86 Proceedings of the Association of AmericanPhysicians 0 578 2.881 n.a. 2.9 n.a. 87 QJM-Monthly Journal of the Association ofPhysicians 77 4171 2.252 0.312 9.7 6.3 88 Revista Clinica Espanola 117 411 0.217 0.026 7.2 5.6 89 Revista de Investigacion Clinica 61 188 0.202 0.066 6.2 6.6 90 Revista Medica de Chile 167 493 0.290 0.084 6.1 6.6 91 Revue de Medecine Interne 185 484 0.375 0.146 4.6 6.7 92 Saudi Medical Journal 208 243 0.153 0.077 5.8 8.9 93 Scandinavian Journal of Primary Health Care 46 509 0.611 0.043 7.4 6.4 94 Schweizerische Medizinische Wochenschrift 368 1220 0.258 0.068 8.8 5.7 95 Scottish Medical Journal 76 449 0.488 0.026 >10.0 5.7 96 South African Medical Journal 96 2242 0.461 0.406 >10.0 6.1 97 Southern Medical Journal 252 3698 0.593 0.067 >10.0 8.0 98 Terapevticheskii Arkhiv 172 362 0.075 0.017 7.4 6.8 99 Tohoku Journal of Experimental Medicine 72 804 0.328 0.014 8.9 8.0 100 Ulster Medical Journal 34 86 0.170 0.000 n.a. 7.8 101 Upsala Journal of Medical Sciences 7 147 0.163 0.000 >10.0 >10.0 102 West Indian Medical Journal 58 166 0.222 0.103 7.7 8.4 103 Western Journal of Medicine 127 1635 0.643 0.197 8.3 5.0 104 Wiener Klinische Wochenschrift 162 857 0.572 0.247 5.3 6.7 105 Yonsei Medical Journal 127 235 0.332 0.024 4.1 7.9 n.a.: not available
Appendix 2 Journals in surgery
No Title SourceItems CitationCount ImpactFactor ImmediacyIndex Cited Half-Life Half-LifeCiting 1 Acta Chirurgica Belgica 67 232 0.27 0.045 6 7.1 2 Acta Neurochirurgica 183 4011 0.817 0.06 8.1 9 3 Aesthetic Plastic Surgery 53 608 0.414 0 7.7 >10.0 4 American Journal of Surgery 198 11950 2.116 0.045 >10.0 6.8 5 American Journal of Surgical Pathology 194 9128 4.269 0.552 6.8 7.5 6 American Surgeon 234 3562 1.101 0.034 6.7 8.1 7 Annales Chirurgiae et Gynaecologiae 68 549 0.55 0.029 9 8.9 8 Annales de Chirurgie 125 661 0.545 0.032 5.8 6.7 9 Annals of Plastic Surgery 221 2975 0.864 0.086 7.6 9.7 10 Annals of Surgery 200 19555 5.987 0.51 >10.0 6.4 11 Annals of Surgical Oncology 108 1439 2.799 0.528 3.2 6.4 12 Annals of the Royal College of Surgeons of England 146 1415 0.439 0.055 9 8 13 Annals of Thoracic Surgery 885 16696 1.828 0.211 5.5 6.5 14 Annals of Vascular Surgery 116 1329 1.073 0.06 6.3 8 15 Archives of Orthopaedic and Trauma Surgery 150 1054 0.507 0.04 9 >10.0 16 Archives of Otolaryngology – Head & Neck Surgery 254 6663 1.527 0.177 >10.0 7.8 17 Archives of Surgery 209 11964 2.629 0.239 >10.0 6.4 18 Arthroscopy 116 2422 1.217 0.224 6.1 7.8 19 Australian and New Zealand Journal of Surgery 194 1792 0.627 0.16 7.1 8 20 British Journal of Neurosurgery 118 956 0.539 0.068 6.4 9.3 21 British Journal of Oral & Maxillofacial Surgery 122 1110 0.771 0.057 8.6 >10.0 22 British Journal of Plastic Surgery 146 2576 0.675 0.116 >10.0 >10.0 23 British Journal of Surgery 235 15907 2.935 0.506 8.5 6.6 24 Burns 120 1373 0.856 0.117 6.1 >10.0 25 Canadian Journal of Surgery 83 1027 0.422 0.06 >10.0 8.2 26 Cardiovascular Surgery 86 778 0.862 0.07 4.3 8.5 27 Ceska a Slovenska Neurologie a Neurochirurgie 60 17 0.059 0 n.a. 7.7 28 Childs Nervous System 131 1119 0.563 0.023 6.4 9.3 29 Chirurg 212 1709 0.721 0.108 5.9 6.3 30 Chirurgische Gastroenterologie 42 106 0.078 0.095 5.5 6.1 31 Cleft Palate-Craniofacial Journal 89 1277 0.718 0.09 9.8 >10.0 32 Clinical Neurology and Neurosurgery 56 904 0.619 0.054 7.8 >10.0 33 Clinical Orthopaedics and Related Research 424 18488 1.182 0.104 >10.0 9 34 Clinical Techniques in Small Animal Practice 23 14 0.228 0 n.a. 8.9 35 Clinical Transplantation 107 1740 1.841 0.224 4.7 5.9 36 Clinics in Plastic Surgery 51 1322 0.816 0.02 10 9.7 37 Critical Reviews in Neurosurgery n.a. 49 0.233 n.a. n.a. n.a. 38 Current Problems in Surgery 12 394 1.826 0.167 6.8 8 39 Dermatologic Surgery 228 1537 1.647 0.206 3.2 8.2 40 Digestive Surgery 129 296 0.81 0.047 3.3 9.4 41 Diseases of the Colon & Rectum 279 6935 1.69 0.176 7.3 7.9 42 Endoscopy 229 3482 1.817 0.236 5.7 4.1 43 European Journal of Cardio-Thoracic Surgery 248 2453 1.187 0.153 3.8 6.4 44 European Journal of Pediatric Surgery 87 534 0.35 0.011 5.5 9.5 45 European Journal of Plastic Surgery 97 149 0.159 0.021 6.4 >10.0 46 European Journal of Surgery 197 1352 0.663 0.061 4.7 8 47 European Journal of Surgical Oncology 141 1539 1.434 0.213 5.4 6.7 48 European Journal of Vascular and EndovascularSurgery 223 1750 1.565 0.139 3.6 7.5 49 European Surgical Research 46 626 0.754 0.065 8.3 8.4 50 Gynaecological Endoscopy 60 159 0.485 0 4.5 6.2 51 Head and Neck-Journal for the Sciences andSpecialties of the Head and Neck 108 2132 1.917 0.111 6.7 8
Appendix 2 (continued)
No Title SourceItems CitationCount ImpactFactor ImmediacyIndex Cited Half-Life Half-LifeCiting 52 Hepato-Gastroenterology 396 2717 0.905 0.086 4.3 8.3 53 Injury – International Journal of the Care of theInjured 206 1569 0.363 0.039 8.1 >10.0 54 International Journal of Colorectal Disease 51 888 1.707 0.137 6.3 7.2 55 International Journal of Oral and MaxillofacialSurgery 87 1600 0.932 0.092 9.2 8.7 56 International Journal of Surgical Pathology 34 95 0.463 0.088 n.a. 7.1 57 International Surgery 37 779 0.488 0.081 7.7 >10.0 58 Journal de Chirurgie 46 411 0.213 0.109 >10.0 5.8 59 Journal of Bone and Joint Surgery – AmericanVolume 180 17733 2.222 0.2 >10.0 8.6 60 Journal of Bone and Joint Surgery – British Volume 221 9475 1.612 0.308 >10.0 9.1 61 Journal of Burn Care & Rehabilitation 82 1109 0.81 0.134 6.6 8.9 62 Journal of Cardiac Surgery 12 828 0.224 0.083 6.2 6 63 Journal of Cardiovascular Surgery 144 1719 0.573 0.021 9.4 9.8 64 Journal of Cataract and Refractive Surgery 274 3835 2.071 0.299 4.2 6 65 Journal of Clinical Laser Medicine & Surgery 36 356 1.205 0.056 4.1 7.3 66 Journal of Craniofacial Surgery 27 406 0.541 0.074 4.9 9.6 67 Journal of Cranio-Maxillofacial Surgery 38 583 0.636 0 7 >10.0 68 Journal of Endovascular Surgery 0 960 3.276 n.a. 3.5 n.a. 69 Journal of Endovascular Therapy 73 31 n.a. 0.425 n.a. 3.9 70 Journal of Hand Surgery – American Volume 136 3573 0.795 0.103 9.1 >10.0 71 Journal of Hand Surgery – British and EuropeanVolume 130 1933 0.495 0.038 7.1 >10.0 72 Journal of Investigative Surgery 39 277 0.756 0.051 6.2 8.9 73 Journal of Laparoendoscopic & Advanced Surgical
Techniques – Part A 59 185 0.783 0.017 2.6 5.1 74 Journal of Neurology Neurosurgery and Psychiatry 284 15244 2.846 0.391 9.6 7.3 75 Journal of Neurosurgery 479 21895 2.918 0.284 10 7.8 76 Journal of Neurosurgical Anesthesiology 50 414 0.937 0.06 5 7.6 77 Journal of Pediatric Surgery 416 7689 1.216 0.159 7.7 7.7 78 Journal of Reconstructive Microsurgery 79 697 0.621 0.063 6.1 >10.0 79 Journal of Refractive Surgery 100 1012 2.061 0.25 3.5 5.5 80 Journal of Shoulder and Elbow Surgery 105 1046 0.973 0.114 5.2 >10.0 81 Journal of Surgical Oncology 150 2616 1.541 0.053 7.8 8.1 82 Journal of Surgical Research 225 4940 1.674 0.151 6.2 6.9 83 Journal of the American College of Surgeons 190 2802 2.805 0.142 3.9 6 84 Journal of the Royal College of Surgeons ofEdinburgh 79 631 0.51 0.038 7.3 7.5 85 Journal of Thoracic and Cardiovascular Surgery 329 14544 3.057 0.407 7.9 6.5 86 Journal of Trauma – Injury Infection and Critical
Care 388 10348 1.498 0.168 8.2 8.5
87 Journal of Vascular Surgery 293 9781 3.114 0.362 6.4 6.9
88 Knee 43 91 0.255 0.233 n.a. 8.7
89 Langenbecks Archives of Surgery 78 908 1.77 0.064 4.6 5.8 90 Lasers In Medical Science 34 330 0.62 0.206 6.2 9.1 91 Lasers In Surgery and Medicine 100 2442 2.348 0.7 6.4 6.5 92 Liver Transplantation 134 998 2.13 0.5 3.1 5.3 93 Microsurgery 70 801 0.517 0.143 7 9.5 94 Minimally Invasive Neurosurgery 32 249 0.805 0.031 4.1 8.8 95 Minimally Invasive Therapy & Allied Technologies 51 214 0.291 0 4.6 5.7 96 Neurochirurgie 58 539 0.39 0 >10.0 8.2 97 Neurocirugia 41 41 0.154 0 n.a. >10.0 98 Neurologia Medico-Chirurgica 121 807 0.387 0.05 7.4 >10.0 99 Neurological Surgery 130 466 0.156 0.008 9.2 7.9 100 Neurosurgery 357 13560 2.899 0.401 6.9 7.7
Appendix 2 (continued)
No Title SourceItems CitationCount ImpactFactor ImmediacyIndex Cited Half-Life Half-LifeCiting 101 Neurosurgery Clinics of North America 63 779 1.265 0.159 5.4 10 102 Neurosurgery Quarterly 13 97 0.5 0 n.a. >10.0 103 Neurosurgical Review 31 386 0.358 0.065 7.8 8.5 104 Obesity Surgery 76 482 1.464 0.342 3.1 6.2 105 Operative Techniques in Sports Medicine 42 107 0.606 0 3.4 6.9 106 Ophthalmic Surgery and Lasers 96 1788 0.775 0.021 8.3 8.1 107 Oral Surgery Oral Medicine Oral Pathology OralRadiology and Endodontics 237 5447 0.865 0.089 >10.0 9.4 108 Otolaryngology – Head and Neck Surgery 364 4677 0.977 0.113 7.3 8.9 109 Pediatric Neurosurgery 109 1209 0.811 0.018 5.9 9.3 110 Pediatric Surgery International 168 701 0.491 0.06 3.8 9.8
111 Phlebology 7 310 0.571 0 7.2 8.9
112 Plastic and Reconstructive Surgery 464 11554 1.423 0.216 9.7 8.7 113 Revue de Chirurgie Orthopedique et Reparatricede l’ Appareil Moteur 129 710 0.212 0.054 >10.0 9.4 114 Scandinavian Journal of Plastic and ReconstructiveSurgery and Hand Surgery 68 942 0.45 0.059 >10.0 >10.0 115 Seminars In Surgical Oncology 73 952 1.65 0.247 4.5 6.3 116 Shock 176 2177 2.785 0.307 3.7 6.4 117 Skull Base Surgery 33 119 0.185 0.03 5.5 >10.0 118 South African Journal of Surgery 15 124 0.159 0 9.3 >10.0 119 Stereotactic and Functional Neurosurgery 5 834 0.657 0.2 5.9 5.7 120 Surgery 255 13128 2.456 0.169 >10.0 6.2 121 Surgery Today-The Japanese Journal of Surgery 240 842 0.356 0.017 4.7 9.6 122 Surgical and Radiologic Anatomy 53 346 0.314 0 6.6 >10.0 123 Surgical Clinics of North America 102 2560 1.252 0.069 >10.0 6.7 124 Surgical Endoscopy – Ultrasound andInterventional Techniques 221 3638 2.056 0.213 4 5.7 125 Surgical Laparoscopy Endoscopy & PercutaneousTechniques 89 1011 0.691 0.067 5.2 6 126 Surgical Neurology 144 3798 1.018 0.118 >10.0 9.4 127 Surgical Oncology – Oxford 13 389 0.293 0 7.2 7 128 Techniques in Neurosurgery 27 35 0.215 0.037 n.a. >10.0 129 Thoracic and Cardiovascular Surgeon 86 937 0.85 0.07 7.4 8.1 130 Transplant International 64 1114 2.049 0.141 4.6 6.3 131 Transplantation 771 22990 4.035 0.475 5.3 6 132 Transplantation Proceedings 1204 10492 0.678 0.021 6.1 5.8 133 Unfallchirurg 153 930 0.496 0.078 6 8.4 134 World Journal of Surgery 248 4939 2.02 0.153 6.3 9 135 Zentralblatt für Chirurgie 230 846 0.302 0.039 5.8 7.2 136 Zentralblatt für Neurochirurgie 19 180 0.939 0 7.5 8.3 n.a.: not available
