Top 50 medical journals from Balkan countries: A bibliometric analysis, 2000–2020

Background: Science Citation Index Expanded (SCIE) is one of the most important indexes that medical journals aspire to be covered by. Currently, SCIE indexes 14,840 peer-reviewed journals across 178 disciplines. Among these journals are 3445 medical journals, divided into more than 40 subject categories. Objectives: To reveal the impact and contribution of medical journals from Balkan countries through the Journal Impact Factor of those journals, the number of articles published by them, and the number of times those articles have been cited. Methods: Balkan countries are countries that fall or fully or partly within the Balkan peninsula. All medical journals from those countries listed in the SCIE were ranked based on cumulative citations between 2000 and 2020. Among them, the top 50 journals in terms of cumulative citations were chosen for the study, which analysed the data on 129,259 research articles and reviews that covered 27 different subject categories within the broad field of medicine. The countries were Bosnia & Herzegovina, Croatia, Greece, North Macedonia, Romania, Serbia, Slovenia, and Turkey Results: The top 50 journals included those published from eight Balkan countries. Turkey had the most journals (21) in the Web of Science (WoS) and Greece had 13 but, when ranked in terms of the number of journals in WoS per million people, Croatia topped the list, with 1.22 journals per million of its population, followed by Greece (1.21 journals). The top-cited journals were Anticancer Research (206,226 citations), International Journal of Oncology (171,654), Oncology Reports (157,467), Molecular Medicine Reports (82,009), and Oncology Letters (69,161). Oncology was the most cited subject category and Croatia, the country with maximum interaction with other Balkan countries, that is, papers in Croatian journals cited journals published from the maximum number of Balkan counties. Conclusion: The study provides insights into the last two decades of progress in academic publishing and in the performances of medical journals published from Balkan countries.


Journals
We used descriptive bibliometric analysis for identifying the most impactful journals, countries, and research areas in Balkan region and defined as Balkan countries the following 12 countries that fall fully or partly in the Balkan peninsula: Albania, Bosnia & Herzegovina, Bulgaria, Croatia, Greece, Kosovo, Montenegro, North Macedonia, Romania, Serbia, Slovenia, and Turkey. 14 All medical journals from Balkan countries covered by the SCIE were ranked based on cumulative citations during 2000-2020 (Supplementary Table 1). First, the 12 countries were filtered from the 'Publication sources' section of the WoS -Incites platform. Next, the research areas, or categories (as assigned by WoS, within the broad field of medicine), were limited to 27, and the journals indexed in ESCI were excluded. This process left us with 77 journals. After excluding journals that had ceased publication or had no JIF (because they had changed their title), we were left with 55 journals, which were then ranked by their cumulative citations and the top 50 among those were taken for further study and form the core of the present study. The five journals that were left out comprised four from Turkey and one from Bulgaria. Because the top 50 had no representation from Albania, Bulgaria, Kosovo, and Montenegro, these four countries were excluded from the study. All the bilingual journals from this list of 50 core journals are referred to by their English title.

Data collection and analysis
The following data were collected for each journal on 11 November 2020: country of publication, number of documents in the WoS database, number of citations, JIF, quartile, JIF without self-citations, and category. We analysed data from 129,259 research articles and reviews that included 27 different WoS categories.
We then analysed the impact of Balkan countries and their interactions. The number of citations earned by the articles published in those 50 journals and sorted by the country of publication of the citing journal served as the proxy for the journals' impact, and we collected these data through the WoS -Incites platform. We searched for each of the 50 journals in the Incites platform and for countries that had published at least three articles in any of those journals. To compare the impact of a country, we used the citation impact data that Incites provides. Citation impact shows the average number of times a given article was cited during a specified period. Because our search was filtered by the country, the citation impact showed the average number of citations received by articles published in journals from a given country between 2000 and 2020.

Statistical analysis
The results were reported as totals and as percentages. The Pearson correlation coefficient (r) was calculated to determine whether the number of publications was correlated to the total number of citations. This relationship was examined to see whether the large numbers of citations obtained by these top-cited journals were a function of their age rather than of the quality and intrinsic value of their content. Statistical analysis was conducted using IBM SPSS Statistics ver. 22.0 for Microsoft Windows (IBM Corp., Armonk, New York).

Ethics
As this analysis will draw on publicly available data and does not directly involve human participants, no ethical review was required for this study.

Results
Among the top 50 journals, eight were published from Balkan countries and were listed in the WoS database. Turkey, with 21 journals, topped the list, followed, in that order by Greece (13 journals), Romania (6), Croatia (5), Serbia (2), and Bosnia & Herzegovina, North Macedonia, and Slovenia (1 each) (Table 1). However, when the population of the country was also taken into account, Croatia was ranked first (1.22 journals for every million people), closely followed by Greece (1.21).
The distribution of published articles by subject category is shown in Figure 1.   Figure 2).  Table 2).
The top 5 journals, according to cumulative citation performances, were all from Greece, (Supplement 2, Table 1). Four of those five journals were on oncology; however, among the 50 journals, the journal with the highest JIF was the Hellenic Journal of Cardiology, with a JIF of 4.047.

Origin of articles and integration with other Balkan countries
All details of the study group are shown in Supplementary Table 1. Of the top-50 journals, 16 had published at least three articles from at least six different Balkan countries as ascertained from the affiliations of the authors. These journals were defined as the most Balkan-interactive journals and were dominated by Greece (five journals) and Croatia (four journals). In the 20 years, Croatian Medical Journal published articles from ten different Balkan countries; Psychiatria Danubina, from nine; and Acta Clinica Croatica and Acta Dermatovenerlogica Croatica, eight each. Overall, journals from Croatia showed the highest diversity in terms of the number of countries from the Balkan region; therefore, Croatia was the country with the highest interaction with other Balkan countries.
A total of 26 journals published more than 50% of the articles originating from the same country as that from which they were published, with Turkey occupying the top position in that list: of the total number of articles published in Mikrobiyoloji Bulteni, 97.6% were from Turkey, the corresponding figures for other journals from Turkey being 96% for Anatolian Journal of Psychiatry, 95.3% for Archives of Neuropsychiatry, 94% for Turkish Journal of Thoracic and Cardiovascular Surgery, and 90.0 for Joint Diseases and Related Surgery (Table 3). These journals have never published more than two articles from other Balkan countries in the last 20 years; however, 16 journals out of the top 50 have done so, from at least six Balkan Countries (Table 3), with Croatian Medical Journal and Journal of BUON leading the diversity, with authors from ten of the twelve Balkan countries to their credit.
The total number of citations was correlated to the number of publications (r = 0.985; p<0.001).
Turkey was next to Greece in being the most prolific Balkan country in terms of both citations and the number of published articles (Supplement 2, Table 2); however, when scaled to the country's population, it ranked the lowest (0.25 journals per million people) (Table 1) Table 3.
Croatian Medical Journal was the top-ranked journal in Croatia and ranked ninth among the top 50, with 18,694 citations (Supplement 2, Table 4). According to the journals' impact in the general medicine research area, the journal ranks second, next to Balkan Medical Journal, with a JIF of 1.247. However, Croatian Medical Journal was the most cited in the general-medicine category over the 20-year period.
Two journals from Serbia (Supplement 2, Table 5) are indexed in the same category, namely Medicine, General & Internal. Vojnosanitetski Pregled was ranked 31st, with 3437 citations, whereas Srpski Arhiv Za Celokupno Lekarstvo was ranked 36th, with 2186 citations. However, in terms of the JIF, these two journals are at the bottom of the list, with JIFs of 0.152 and 0.142, respectively.
Radiology and Oncology is the only journal from Slovenia (Supplement 2, Table 5) and covers the same area as the one that was the most frequently covered by the top 50 journals, namely Radiology, Nuclear Medicine & Medical Imaging and Oncology. The Journal Impact Factor of Radiology and Oncology was 1.746 (4843 citations) and the journal was placed in Q3 in Radiology, Nuclear Medicine & Medical Imaging and in Q4 in Oncology.
Of the Slovenian, Bosnian, and North Macedonian journals (listed in Supplement 2; Table 5

Discussion
Of the 27 subject categories covered by the top 50 journals, Oncology was at the top, with eight journals; however, most of them fell either in Q3 or in Q4 within the category, and none was placed in Q1. International Journal of Oncology and Oncology Reports, both from Greece, appear to be the most impactful oncology journals in that category and were placed in Q2. According to the study by Taş, 15 the most-cited oncology articles have been published mainly in New England Journal of Medicine, The Lancet, Nature Reviews, and Cancer. These data show that high-quality research with high citation potential is more likely to be published in world-renowned journals than to the regional ones.
Rosenkrantz and Ayoola 16 found that journals focusing on such subspecialties of radiology as cardiac imaging and molecular imaging have the highest JIF. However, of the four radiology journals in the present study, the only general radiology journal from Turkey, Diagnostic and Interventional Radiology, had the highest JIF of all (Table 2).
Medicine, General & Internal, was the second leading category, with seven journals, followed by Medicine, Research & Experimental, with five journals. Although the number of journals was very close to that for oncology, general medicine accounted for only 8% of the total articles and only 4% of the total citations, and journals in that category were placed in Q3 and Q4. Croatian Medical Journal was the most cited general medicine journal, with 18,694 citations, followed by Turkish Journal of Medical Sciences, with 6208 citations. However, Croatian Medical Journal earned the highest number of citations among the general medicine journals, and Balkan Medical Journal was the most impactful journal in the category with a JIF of 1.553. Among the 27 subject categories, Medicine, General & Internal was a significant one; because journals in that category publish articles from all fields of medicine, those journals represent a broad spectrum of subject categories. General medicine journals should be a rallying point for the local and international exchange of ideas, and it will be a pity if, in the 21st century, general medicine journals are successful only locally. Therefore, regional journals should strive harder to be more prominent internationally. 17 Journals from Turkey showed the widest distribution in that they represented 20 research categories, followed by Greece (8 categories) and Romania (7 categories). Turkey had two paediatrics journals in the top 50 and is the only Balkan country to publish journals on paediatrics. Despite its low JIF (0.349), Turkish Journal of Pediatrics ranked 13th among the top 50 journals, with 8886 citations.
Turkish Neurosurgery and Archives of Neuropsychiatry were the only clinical neurology journals in the top 50. Sarica et al 18 showed that Turkey contributed 2.5% to neurosurgical journals and ranked 10th globally. Our study showed that Turkish neurosurgical journals ranked first in the Balkan region, with the majority of authors being Turkish (60% in Turkish Neurosurgery and 96% in Archives of Neuropsychiatry). Acta Orthopaedica et Traumatologica Turcica is one of the only two orthopaedics journals in the top 50. Another orthopaedics journal is Joint Diseases and Related Surgery. In the study by Gürbüz et al. 9 , Turkey ranked 14th among 122 countries in terms of the number of articles published on orthopaedics, and Turkey's contribution to this field continues to increase. Those two journals were the only ones from the Balkan region to contribute to the literature on orthopaedics in SCIE.
Among the top 50 journals, only one represented microbiology. Apart from Mikrobiyoloji Bulteni, no other journal from the Balkan countries is indexed in SCIE, which makes the journal particularly important to the Balkan region. Macias et al 19 showed that continued existence of many so-called classic journals devoted to microbiology is threatened because new microbiology journals are more popular. Although the only microbiology journal in the Balkan region, the journal is published only in Turkish, which may explain why the JIF of Mikrobiyoloji Bulteni keeps fluctuating over the years despite it being the sole representative of microbiology.
Among the top 50 journals, only two dealt with Gastroenterology & Hepatology, namely the Journal of Gastrointestinal and Liver Diseases, from Romania, and Turkish Journal of Gastroenterology: the former was ranked first among the journals from Romania (10th among the top 50). These two journals are sole representatives of the Balkan countries in SCIE in the Gastroenterology & Hepatology category. Azer and Azer 20 found that the mean number of citations to papers published before 2000 was lower than that for papers published after 2000. However, the mean number of citations to articles published after 2000 tended to be higher, possibly indicating the significance of scientific content and the tendency of researchers to cite more recent work. The fact that these two journals indexed in SCIE are in the top-50 may be due to the increasing popularity of, and therefore more citations to, this research area. Similarly, citations of both these show that their JIFs have been increasing.
Four journals -all from Greece -published more than 10,000 articles each between 2000 and 2020 (Table 2). On the other hand, Balkan Journal of Medical Genetics from North Macedonia published only 329 articles in 20 years, making it the journal with the fewest publications. Although there are many journals devoted to medical genetics, only a few are from regions outside Western Europe and North America. 10,21 Among the journals from Balkan countries, only two in the category Cardiac & Cardiovascular Systems are indexed in SCIE, namely the Hellenic Journal of Cardiology, from Greece, which had the highest JIF (4.047) among the top 50, the other being the Anatolian Journal of Cardiology, from Turkey (JIF 1.223).
When we analysed the listed journals taking into account self-citations, two showed a significant difference between their JIF with and without self-citations: Joint Diseases and Related Surgery had the highest self-citation rate of 78%, followed by Hellenic Journal of Cardiology, of 48%. Although Hellenic Journal of Cardiology had the highest JIF in the top 50, when the list is sorted by the JIF without self-citations, the journal falls to the 6th place and Joint Diseases and Related Surgery falls to the 43th place from the 23rd. A high self-citation rate does not always imply manipulation. When journals get on in the years, their archives expand and their visibility increases; these factors can increase a journal's self-citation rate organically. However, the impact factor without self-citation is an important parameter to see the changes in the journal's rank in a given category.
We acknowledge that the present study has several limitations, one of them being that it was based on data only from the WoS: for better insights into the impact of medical journals from Balkan countries, data from other indices such as Scopus should also be considered (the coverage of which is broader than that of WoS). 22 Another limitation was that we capped the list at 50 whereas to investigate Balkan countries' contribution to the literature, all journals from the region should be investigated irrespective of the number of citations.
In conclusion, this study shows that top journals from Balkan countries are dominated by a few categories such as Oncology and General Medicine in terms of the number of articles published and the number of times they are cited. Greece and Turkey were the most prominent countries in terms of the number of journals in the top 50, cumulative citations, and the number of published articles. On the other hand, Croatia had the highest interactions with other Balkan countries in that it published papers by authors from maximum number of Balkan countries. Balkan journals thus have a broad representation in the field of medicine and a considerable impact. Lastly, more studies, and in greater details, are needed to broaden our understanding of the contribution of journals from Balkan countries.