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Fertility and Sterility and impact factor
EDITOR’S CORNER Fertility and Sterility and impact factor Togas Tulandi, M.D., M.H.C.M.,a Fady F. Shehata, MB.BCh. M.Sc.,a and Alan DeCherney, M.D.b a
Department of Obstetrics and Gynecology, McGill University, Montreal, Quebec, Canada; and b NICHD/NIH, Bethesda, MA
Increasing the number of articles and reviews does not lead to an increased impact factor. The type and quality of the articles might influence this result. Compared with the traditional 2-year impact factor, a 5-year impact factor fluctuates little, and may be a better indicator for evaluation of published journals. (Fertil Steril 2010;93:2105–6. 2010 by American Society for Reproductive Medicine.) Key Words: Impact factor, citation, Fertility and Sterility, Scopus, Thompson
Impact factor is considered to be one of the important measures in evaluating the quality of scientific journals. It is also used by academic institutions and funding agencies to evaluate researchers, for academic promotion, financial bonus, or salary increase. As a result, many authors target their publications to high impact journals. On a social level, it became similar to intelligence quotient, where researchers who published in low impact factor journals are considered inferior to those who published in high impact factor journals. Impact factor was first introduced by Garfield and Sher in 1963 (1, 2). At present, it is still the most important measure in evaluating published literature. Impact factor is calculated using a fixed equation based on articles published in 2 years. For example, the impact factor for the year 2000 is equal to the total number of citations in the year 2000 for ‘‘citable’’ articles published in 1999 and 1998 divided by the total number of citable articles in 1999 and 1998. Thomson Reuters, an independent information resource for health care professionals and scientists has been publishing impact factors of most peer-reviewed journals in Journal Citation Reports (JCR) (3). However, the particular citable articles that provide a foundation for calculating the impact factor are not revealed to the public; only the sum of these articles are provided. A citable item according to JCR could be either a research article or a review. At present, there are tools available allowing researchers and statisticians to calculate the impact factor by themselves. For this report, we used Scopus database, a product of Elsevier to calculate the impact factor and other related calculations (4). Scopus is the largest abstract and citation database in Scientific, Technical and Medical publishing, including 15,000 peer-reviewed titles from more than 4,000 publishers. Fertility and Sterility is now integrated with Scopus. We evaluated the 2-year impact factors of Fertility and Sterility for the years 2000–2008 using Scopus and compared them to those published by JCR. The results show that the impact factors are not Received October 11, 2009; revised January 11, 2010; accepted January 26, 2010; published online March 15, 2010. T.T. has nothing to disclose. F.F.S. has nothing to disclose. A.D. has nothing to disclose. Reprint requests: Fady Shehata, MB.BCh., M.Sc., Department of Obstetrics and Gynecology, McGill University. 687 Pine Avenue West, Montreal, H3A 1A1, Quebec, Canada (FAX: 514-843-1448; E-mail: fady. [email protected]).
0015-0282/10/$36.00 doi:10.1016/j.fertnstert.2010.01.065
FIGURE 1 Impact factors of Fertility and Sterility as calculated using Scopus and published by Journal Citation Report (JCR).
Tulandi. Fertility and Sterility and impact factor. Fertil Steril 2010.
FIGURE 2 Number of original articles published in Fertility and Sterility in 1998–2008.
Tulandi. Fertility and Sterility and impact factor. Fertil Steril 2010.
Fertility and Sterility Vol. 93, No. 7, May 1, 2010 Copyright ª2010 American Society for Reproductive Medicine, Published by Elsevier Inc.
2105
FIGURE 3
FIGURE 4
Number of review articles published in Fertility and Sterility in 1998–2006.
Five-year impact factors of Fertility and Sterility as calculated using Scopus and published by Journal Citation Report (JCR).
Tulandi. Fertility and Sterility and impact factor. Fertil Steril 2010.
Tulandi. Fertility and Sterility and impact factor. Fertil Steril 2010.
the same, but the trend during those years is similar (Fig. 1). To evaluate this phenomenon, we calculated the number of articles and reviews in Scopus. We found that in contrast to the years 1998–2002, the number of articles started to increase consistently from 2003 until 2006 (Fig. 2). Figure 3 shows that the number of review articles increased from 2001 with a peak in 2004. The increase in the number of reviews is not followed by increased impact factor. In 2007 the numbers of articles and reviews were lower than those in the previous year. Because impact factor is calculated using the citations from the previous 2 years, this decrease might have played a role in increasing impact factor for the year 2008. The 2008 impact factor for Fertility and Sterility is 4.17 as published by JCR and 2.7 as calculated using Scopus. The journal ranks third in the Obstetrics and Gynecology category and second in the Reproductive Biology category. The widely used 2-year impact factor, however, does not accurately capture real citation patterns of a journal, as articles older than 2 years may often be among the most cited. In January 2009, Thomson Reuters released an expanded version of reports including a 5-year impact factor that refers to articles published in the previous 5 years. It might be a better indicator, as it does not fluctuate between years as much as the 2-year impact factor. We calculated the 5-year
impact factor for Fertility and Sterility according to Scopus and JCR for the years 2000–2008. The fluctuation between years becomes less pronounced. However, similar to that of 2-year impact factor, we observed the same increase in impact factor for 2008 compared with the previous years (Fig. 4). Fertility and Sterility is available online through www.fertstert.org and through Elsevier’s ScienceDirect. As of July 2009, an estimated of 713,506 full-text articles from Fertility and Sterility were requested from ScienceDirect, and the Web site had more than 1,057,791 total views. Compared with 2008, this is an increase of 16% in requests for articles and 64% in total views. The availability of the journal electronically facilitates access to published articles and might influence future impact factors. Contrary to previous beliefs, our analysis suggests that increasing the number of articles and reviews does not lead to increased impact factor. The type and quality of articles might influence this result. Compared with the traditional 2-year impact factor, a 5-year impact factor fluctuates little, and may be a better indicator for evaluation of published journals.
REFERENCES 1. Garfield E. The history and meaning of the journal impact factor. J Am Med Assoc 2006;295:90–3. 2. Garfield E, Sher IH. New factors in the evaluation of scientific literature through citation indexing. Am Documen 1963;14:195–201.
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Tulandi et al.
3. Thomson R. Journal Source Data. In: Journal Citation Reports. Vol. 2010: Thomson R, ed. 2008. Available at: http://admin-apps.isiknowledge.com/ JCR/help/h_sourcedata.htm#sourcedata. Accessed: January 11, 2010.
Fertility and Sterility and impact factor
4. Scopus database. Scopus. In: Vol. 2009. New York: Elsevier B.V, 2009. Available at: http://info.scopus.com/about/. Accessed: January 11, 2010.
Vol. 93, No. 7, May 1, 2010
Department of Obstetrics and Gynecology, McGill University, Montreal, Quebec, Canada; and b NICHD/NIH, Bethesda, MA
Increasing the number of articles and reviews does not lead to an increased impact factor. The type and quality of the articles might influence this result. Compared with the traditional 2-year impact factor, a 5-year impact factor fluctuates little, and may be a better indicator for evaluation of published journals. (Fertil Steril 2010;93:2105–6. 2010 by American Society for Reproductive Medicine.) Key Words: Impact factor, citation, Fertility and Sterility, Scopus, Thompson
Impact factor is considered to be one of the important measures in evaluating the quality of scientific journals. It is also used by academic institutions and funding agencies to evaluate researchers, for academic promotion, financial bonus, or salary increase. As a result, many authors target their publications to high impact journals. On a social level, it became similar to intelligence quotient, where researchers who published in low impact factor journals are considered inferior to those who published in high impact factor journals. Impact factor was first introduced by Garfield and Sher in 1963 (1, 2). At present, it is still the most important measure in evaluating published literature. Impact factor is calculated using a fixed equation based on articles published in 2 years. For example, the impact factor for the year 2000 is equal to the total number of citations in the year 2000 for ‘‘citable’’ articles published in 1999 and 1998 divided by the total number of citable articles in 1999 and 1998. Thomson Reuters, an independent information resource for health care professionals and scientists has been publishing impact factors of most peer-reviewed journals in Journal Citation Reports (JCR) (3). However, the particular citable articles that provide a foundation for calculating the impact factor are not revealed to the public; only the sum of these articles are provided. A citable item according to JCR could be either a research article or a review. At present, there are tools available allowing researchers and statisticians to calculate the impact factor by themselves. For this report, we used Scopus database, a product of Elsevier to calculate the impact factor and other related calculations (4). Scopus is the largest abstract and citation database in Scientific, Technical and Medical publishing, including 15,000 peer-reviewed titles from more than 4,000 publishers. Fertility and Sterility is now integrated with Scopus. We evaluated the 2-year impact factors of Fertility and Sterility for the years 2000–2008 using Scopus and compared them to those published by JCR. The results show that the impact factors are not Received October 11, 2009; revised January 11, 2010; accepted January 26, 2010; published online March 15, 2010. T.T. has nothing to disclose. F.F.S. has nothing to disclose. A.D. has nothing to disclose. Reprint requests: Fady Shehata, MB.BCh., M.Sc., Department of Obstetrics and Gynecology, McGill University. 687 Pine Avenue West, Montreal, H3A 1A1, Quebec, Canada (FAX: 514-843-1448; E-mail: fady. [email protected]).
0015-0282/10/$36.00 doi:10.1016/j.fertnstert.2010.01.065
FIGURE 1 Impact factors of Fertility and Sterility as calculated using Scopus and published by Journal Citation Report (JCR).
Tulandi. Fertility and Sterility and impact factor. Fertil Steril 2010.
FIGURE 2 Number of original articles published in Fertility and Sterility in 1998–2008.
Tulandi. Fertility and Sterility and impact factor. Fertil Steril 2010.
Fertility and Sterility Vol. 93, No. 7, May 1, 2010 Copyright ª2010 American Society for Reproductive Medicine, Published by Elsevier Inc.
2105
FIGURE 3
FIGURE 4
Number of review articles published in Fertility and Sterility in 1998–2006.
Five-year impact factors of Fertility and Sterility as calculated using Scopus and published by Journal Citation Report (JCR).
Tulandi. Fertility and Sterility and impact factor. Fertil Steril 2010.
Tulandi. Fertility and Sterility and impact factor. Fertil Steril 2010.
the same, but the trend during those years is similar (Fig. 1). To evaluate this phenomenon, we calculated the number of articles and reviews in Scopus. We found that in contrast to the years 1998–2002, the number of articles started to increase consistently from 2003 until 2006 (Fig. 2). Figure 3 shows that the number of review articles increased from 2001 with a peak in 2004. The increase in the number of reviews is not followed by increased impact factor. In 2007 the numbers of articles and reviews were lower than those in the previous year. Because impact factor is calculated using the citations from the previous 2 years, this decrease might have played a role in increasing impact factor for the year 2008. The 2008 impact factor for Fertility and Sterility is 4.17 as published by JCR and 2.7 as calculated using Scopus. The journal ranks third in the Obstetrics and Gynecology category and second in the Reproductive Biology category. The widely used 2-year impact factor, however, does not accurately capture real citation patterns of a journal, as articles older than 2 years may often be among the most cited. In January 2009, Thomson Reuters released an expanded version of reports including a 5-year impact factor that refers to articles published in the previous 5 years. It might be a better indicator, as it does not fluctuate between years as much as the 2-year impact factor. We calculated the 5-year
impact factor for Fertility and Sterility according to Scopus and JCR for the years 2000–2008. The fluctuation between years becomes less pronounced. However, similar to that of 2-year impact factor, we observed the same increase in impact factor for 2008 compared with the previous years (Fig. 4). Fertility and Sterility is available online through www.fertstert.org and through Elsevier’s ScienceDirect. As of July 2009, an estimated of 713,506 full-text articles from Fertility and Sterility were requested from ScienceDirect, and the Web site had more than 1,057,791 total views. Compared with 2008, this is an increase of 16% in requests for articles and 64% in total views. The availability of the journal electronically facilitates access to published articles and might influence future impact factors. Contrary to previous beliefs, our analysis suggests that increasing the number of articles and reviews does not lead to increased impact factor. The type and quality of articles might influence this result. Compared with the traditional 2-year impact factor, a 5-year impact factor fluctuates little, and may be a better indicator for evaluation of published journals.
REFERENCES 1. Garfield E. The history and meaning of the journal impact factor. J Am Med Assoc 2006;295:90–3. 2. Garfield E, Sher IH. New factors in the evaluation of scientific literature through citation indexing. Am Documen 1963;14:195–201.
2106
Tulandi et al.
3. Thomson R. Journal Source Data. In: Journal Citation Reports. Vol. 2010: Thomson R, ed. 2008. Available at: http://admin-apps.isiknowledge.com/ JCR/help/h_sourcedata.htm#sourcedata. Accessed: January 11, 2010.
Fertility and Sterility and impact factor
4. Scopus database. Scopus. In: Vol. 2009. New York: Elsevier B.V, 2009. Available at: http://info.scopus.com/about/. Accessed: January 11, 2010.
Vol. 93, No. 7, May 1, 2010