PEDIATRICS Vol. 106 No. 2 August 2000, pp. 377

In Which Journals Will Pediatricians Find the Best Evidence for Clinical Practice?

To the Editor.

Birken and Parkin have performed a useful service in identifying "In which journals will pediatricians find the best evidence for clinical practice?" (Pediatrics 1999;103:941-947). Had they not succumbed to general allegations about journal impact factors and simply consulted any recent year of the Science Citation Index Journal Citation Reports, they would have learned that the same pediatric and general medical journals they identified were also among the top 10 cited in Pediatrics. Thus, citation rankings for these journals correlate very well indeed with their findings.

Their inclusion of titles such as Journal of Neurosurgery, and Gastroenterology reflect the choices of the Cochrane Database of Systematic Reviews (CDSR), which are not journals to be found in the average pediatrician's practice.

Finally, the inclusion of the Canadian Medical Association Journal is not surprising for the Canadian Paediatric Society (CPS) but is not one of the general journals most cited by pediatric investigators.

Eugene Garfield
Chairman Emeritus, ISI
Philadelphia, PA 19104

In Reply.

We thank Dr Garfield for his comments. Our discussion of impact factors was not the main thrust of our article, nor was it intended to diminish the importance of Dr Garfield's groundbreaking work. As the inventor of the Science Citation Index (SCI), Dr Garfield himself has warned "against the indiscriminate use of these data ... [I]mpact simply reflects the ability of journals and editors to attract the best papers."¹ Our objective was to identify the journals containing the best evidence relating to the clinical practice of pediatrics. We hypothesized that impact factors might not accurately identify the papers that have the greatest impact on the practicing pediatrician, because (as noted by Dr Garfield) "only a fraction of doctors do research," and hence have the opportunity to cite published research. Although Dr Garfield is correct that the journals identified in our study rank highly in the SCI Journal Citation Reports in the categories of pediatrics and general and internal medicine, the correlation is imprecise. Below we have listed the top 10 journals by impact factor in the pediatrics category of the 1995 SCI Journal Citation Report.² Because there is considerable overlap with our list, it does not include the general medical journals that we identified as contributing to the evidence in pediatric practice (listed in the second table, from the general and internal medicine category of the 1995 SCI Journal Citation Report). Furthermore, the relative weightings of the pediatric journals and general and internal medicine journals are quite different in our study as compared with the 1995 SCI Journal Citation Report. In addition, journals not identified by our study are listed in the pediatrics category of the 1995 SCI Journal Citation Report attributable to high-impact factor (notably, Pediatric Research), but do not aim to provide evidence for clinical pediatric practice.

Ranking JournalPediatrics Category Impact Factor  1. Journal of Pediatrics 2.859  2. Pediatric Research 2.857  3. Pediatrics 2.710  4. Pediatric Infectious Disease Journal 1.819  5. Archives of Disease in Childhood 1.582  6. Medical and Pediatric Oncology 1.543  7. Pediatric Pulmonology 1.433  8. American Journal of Diseases of Children 1.433  9. American Journal of Pediatric Hematology 1.271 10. Journal of Pediatric Gastroenterology and   Nutrition 1.243

Ranking JournalGeneral and Internal Medicine Impact Factor 1. New England Journal of Medicine 22.412 2. Lancet 17.490 4. Journal of the American Medical   Association 7.686 7. British Medical Journal 4.549

We agree with Dr Garfield's comment that inclusion of some journals resulted from the choice of topics selected by the Cochrane Collaboration for systematic review. We have identified this as a limitation of our study method. Finally, we would suggest that the inclusion of the Canadian Medical Association Journal in the strategy that used the Canadian Paediatric Society Statements is provocative. Similarly, we found that the Cochrane Database of Systematic Reviews was more likely to include non-North American journals than statements of the American Academy of Pediatrics or Canadian Paediatric Society. Is it possible that readers (whether practitioner or investigator) place a different value on journals that originate from their own (or closely related) nation?

Patricia C. Parkin
Catherine Birken
Department of Pediatrics, University of Toronto Faculty of Medicine
Hospital for Sick Children
Toronto, Canada M5G 1X8

REFERENCES

1. Garfield E How can impact factors be improved? Br Med J. 1996; 313:411-413 [Free Full Text]
2. Garfield E. 1995 SCI Journal Citation Reports: A Bibliometric Analysis of Science Journals in the ISI Database. Philadelphia, PA: Institute for Scientific Information, Inc; 1996