Background and Objectives: Indexing texts are one of the important tools that help researchers, scholars, students, searchers, and others who need documents with complete information in them researches. One of the benefits of credible indices is the high number of international referrals to these indices, which increases the visibility of these papers globally. As a result, it is possible to be cited with other papers and provide the opportunity to solve the content of the papers in the epistemological body of the scientific field related to their subject.  The highest indices in the current division of the Ministry of Health are ISI, PubMed and Scopus. Given that valid indices have indicators for evaluating journals and accepting them, so the possibility of accepting various articles in indices based on the indicators that these indices apply can be different. Identifying the status and composition of papers indexed in the indices, while presenting an image of the orientation of the researchers in the methodology used in the research, can be an introduction to the study of the orientation of the incident in the content composition of the indices under consideration.
Methodology: The population of this analytical cross-sectional study was all papers indexed at ISI, PubMed and Scopus bases with organizational affiliation of Ahwaz Jundishapur University of Medical Sciences and the 2015 publish date. The research sample was determined using a census method and 281 papers were included in the present study. Then, the status of the articles studied was studied with three factors: "type of study", "aim of the study" and "field and subject area", as well as the relationship between the methodological tend of the papers in the three factors mentioned with the probability of accepting papers in valid indices. The relationship between the methodological orientation of the two "aim" and "type of study" factors with the "field and subject area" was also examined. The descriptive statistics such as charts & etc were used andChi-square test by SPSS software was used for analyzing the data.
Findings: Of the 281 entered papers in this research, the most papers were cross-sectional analytical (86 articles, 30.6%), and the smallest papers were case report (0 articles, 0%), the cohort (0 articles, 0%) and then systematic review (1 article, 0.4%). Also, the 3 international indices examined in terms of the type of study papers were oriented toward papers of a cross-sectional type. The highest number of studied papers were in the field of public health (37 studies, 13.2%), and the smallest number of studies were in the field of medical history, hospitals and health centers, medical profession (0 studies). Chi-square test determined the relationship between descriptive cross-sectional studies and general public health topics in the present study. Also, there was a meaningful statistical relationship between descriptive cross-sectional studies and the subject area of contagious diseases. A direct relationship between the aim of treatment and the subject area of the pathology in the studied papers was also confirmed by this test. Also, the Chi-square test between the papers aimed at treatment and the subject area of pharmacology has also shown a direct relationship. Finally, this test showed that there was a direct relationship between the prevention objective and the public health subject in the studies.
Discussion: Assigning the most types of studies to cross-sectional studies can have many reasons, including the fact that researchers are more familiar with the stages of these studies, doing cross-sectional research is possible in many disciplines and groups at the university. On the other hand, each type of study has its own advantages and very few reports of cases, narrative review and systematic review, and the absence of a cohort study in the studied papers is not justified. In reviewed studies, the high number of studies aimed at treatment in the studies papers in this study itself is a strength point, however, the low number of articles aimed at prevention is one of the weaknesses of the university. One of the reasons that a large number of papers have been in public health subject area, is the multitude of related groups in the field. Also, in these groups, the number of professors and students is high and the research topics are very diverse. One of the reasons for the direct link between "public health" studies and "descriptive-cross-sectional" studies in the studied papers can be the nature of research in this regard. However, the public health area has received the largest number of articles in studied papers, the lack of systematic reviews and reviews in this subject area is unexpected. The results showed that the acceptance of clinical trials in international profiles was lower than other types of studies. Perhaps the credible international indices, due to the importance of clinical trials, would have a more rigorous line-up than other studies in accepting these studies.