Equal Contributions And Credit Given To Authors In Public Health Journals During A10-year Period

Background:There is a trend in authors giving equal contributions and credit in scientific manuscripts. The prevalence and characteristics have been investigated in the five general medicine journals with the highest impact factors, four critical care medicine journals and four anesthesiology journals with high impact factors. But this prevalence is not known in other journals. This study aimed to identify longitudinal trends and characteristics of the practice of explicitly giving equal credit in public health journals.Methods:Manual searches were conducted to identify original research articles with equally credited authors published between January1,2002and December31,2011in five public health journals with highest impact factors (2010JCR report)(Annual Review of Public Health, Epidemiologic Reviews, Environmental Health Perspectives, Epidemiology, and International Journal of Epidemiology). The Instructions to Authors in the five journals are also searched for the information on giving equal credit to authors. Results:The practice of authors given equal credit was found in three of the five journals. No article with authors given equal credit was identified in Annual Review of Public Health and Epidemiology. Only one article with authors given equal credit was identified in Epidemiologic Reviews. But articles with equally credited authors in Environmental Health Perspectives and International Journal of Epidemiology form a great proportion of the total number of articles published in2011vs2010. Statistically significant difference was noted in Environmental Health Perspectives and International Journal of Epidemiology in yearly prevalence (r=0.894,P=0.000; r=0.839, P=0.002, respectively). The first two authors listed in the byline received equal credit in the majority of the time but the practice was also applied to authors in nearly every position in the byline. In the journals of Environmental Health Perspectives and International Journal of Epidemiology, the authors giving equal credit are mainly from United States and England. Finally none of the journals provided specific guidance regarding this practice in their Instructions to Authors.Conclusions:The practice of explicitly giving authors equal credit is not found in all the5journals. However this practice should be better to be addressed in the guidance for authors. Although this phenomenon has been addressed, it has not aroused enough attention in the scientific research field.