Background

For historical reasons, the field of neurosurgery has developed in China along its own unique path [1, 2]. Today’s China is more open than ever, including in academic research. Chinese neurosurgeons need to learn from their foreign counterparts, while doctors outside China also need to know what Chinese doctors have done. Publications represent the best bridge between these groups. In recent years, China doctors have begun to realize the importance of publication, and have begun to capture their discoveries and experience in publications to communicate their findings to others. As the main international academic language is English, Chinese neurosurgeons have to publish their work in English to reach worldwide recognition. As a result, language limitations obstruct academic exchanges between Chinese doctors and those from other countries.

Chinese neurosurgeons have published a significant body of work. Thus far, Chinese neurosurgery has made significant achievements in both clinical practice and scientific research, obtaining worldwide recognition and respect. As China has the largest population in the world, it should represent the largest disease resource database, and the voices of Chinese physicians should be well represented in the academic discussion. The first task is to understand the work that has already been done by Chinese neurosurgeons and China’s current position in the field.

The most commonly used medical biological databases—PubMed, Web of Science, and Google Scholar—each have their own strengths and weaknesses [3]. Among them, Web of Science (WoS) is a strong research database that was officially inaugurated in 2004 by the Thomson Scientific and Health Care Corporation. The WoS database not only contains the affiliations of all authors but also provides the numbers of citations of published articles. WoS provides access to Thomson Reuter’s multidisciplinary databases of bibliographic information. WoS is a powerful web interface providing access to the citation database [4]. WoS offers a significant advantage for literature reviews in some particular fields [5, 6], especially for efforts to understand overall trends [7, 8]. Previous studies have evaluated Chinese neurosurgical publications, but they only focused on local Chinese journals [9] or carried out only superficial research on Chinese neurosurgical publications [10]. The aim of this study was to comprehensively analyze neurosurgical publications in China using the WoS database.

Methods

The Web of Science (WoS) database was accessed on May 4, 2015. Publications in the Web of science core collection database were searched for publications of all types with authors’ addresses containing “neurosurg*” or “surgical neurology”. The number of publications and other information was obtained. In the first stage, an international comparison of neurosurgeons’ research outputs by country was carried out. Then, the search was divided into two periods, before 2010 (1928–2009) and after 2010 (2010 to present) to extract more detailed information.

Chinese neurosurgical publications were identified using the following search strategy: ((address: neurosurg*) OR (address: surgical neurology)) AND (address: China). Data were extracted from the search results to obtain information such as document type, countries/territories, funding agencies, organizations, publication year, title and research area. Then, the search results were analyzed using the “analyze results” tool on the WoS webpage.

We only included articles in the citation report, excluding reviews, meeting abstracts, letters, editorial material and other document types. We searched for papers with Chinese corresponding authors cited more than 100 times to identify Chinese neurosurgeons playing important roles in research. We also spoke with senior experts in the neurosurgical field and manually retrieved some original documents to ensure a complete survey.

Publications from the departments/institutes of neurosurgery in China and data sources from the Web of science core collection database were searched. The types of publications included articles, letters, reviews, proceedings papers, editorial materials, and more. Analyses included yearly research output, research output over the whole time period, WoS subject category, authors, organizations/institutes that submitted published articles, and the names of journals publishing articles.

Data from WoS were exported to a Microsoft Office® Excel spreadsheet and then transferred to a Microsoft Word document. We considered the top ranked publications in each item. ANOVA, Student’s t-, and c2 tests were used to assess the statistical significance of differences in the mean citation numbers among different study periods (SPSS version 17.0; SPSS Inc., Chicago, IL, USA). A p value <0.05 was considered statistically significant (2-tailed test).

Result

Proportional growth in Chinese publications

Worldwide, neurosurgical departments have been involved in a total of 165,365 publications, 61,411 of which were published since the beginning of 2010. Before 2010, Chinese neurosurgeons published only 2 % of total publications, ranking tenth in the world (Fig. 1). Chinese neurosurgical authors contributed 13 % of publications in the period after 2010, rising to the second most productive country in the world (Fig. 2).

Fig. 1
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The proportion of neurosurgical publications before 2010 by country. Before 2010, China accounted for 2 % of neurosurgical publications, ranking 10th in the world

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Fig. 2
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The proportion of neurosurgical publications by country from 2010 to the present. China accounts for 13 % of neurosurgical publications, ranking 2nd in the world

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Chinese neurosurgeons have published a total of 10,770 publications. The number of publications has increased every year, with especially rapid growth observed in recent years (Fig. 3).

Fig. 3
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The number of Chinese neurosurgical publications per year has increased rapidly

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The greatest proportion of these publications are articles, accounting for more than 87 %, far more than other document types (Fig. 4).

Fig. 4
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Document types of Chinese publications

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Details of Chinese neurosurgical publications

The 10 journals most frequently publishing articles by Chinese neurosurgeons differ from those publishing articles by neurosurgeons from throughout the world (Table 1). Chinese neurosurgeons have published few articles in the most famous magazines in the field of neurosurgery, such as “Journal of Neurosurgery” and “Neurosurgery”. Instead, they have frequently published papers in general medical journals such as “Chinese Medical Journal” and “PLOS One”. Journals emphasizing basic research have also published many articles by Chinese neurosurgeons.

Table 1 The top 10 journals publishing Chinese’s and world neurosurgeon’s publications
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There are 34 Chinese organizations that have published more than 100 publications in this research area (Table 2). The most prolific is “Capital Medical University”, which has published 1287 publications, accounting for 12 % of all Chinese neurosurgical publications. Most of these organizations are universities located in central cities of Eastern China.

Table 2 Organizations who published more 100 publications in China
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We identified 19 studies written by Chinese authors that have been cited more than 100 times (18 were identified from a database search, while 1 came from consulting a senior expert). The details of these studies are shown in Table 3. Most of these studies are basic research. However, some report research on clinical practice such as brain trauma, brain stem cavernous malformations, and epidemiological investigations in China. Because of China’s huge population and number of patients, the experiences and discoveries of Chinese neurosurgeons are an important part of the global knowledge base.

Table 3 Chinese neurosurgical publications cited more than 100
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Research area trends

Comparing publications before and after 2010, the distribution of worldwide publications among different research areas has changed somewhat. The following research areas have increased in proportion between the two periods: oncology, research experimental medicine, orthopedics, general internal medicine, cardiovascular system, cardiology, cell biology, pharmacology, and pharmacy.

At the same time, the proportions of the following research areas have decreased: neurosciences, neurology, surgery, radiology, nuclear medicine, medical imaging, pediatrics, pathology, psychiatry and endocrinology metabolism. However, these changes are not statistically significant (Fig. 5).

Fig. 5
figure 5

Research area trends and differences between China and the rest of the world. Comparing publications before and after 2010, the proportions of different research areas have changed somewhat. The proportions of the following research areas have increased: oncology, research experimental medicine, orthopedics, general internal medicine, cardiovascular system, cardiology, cell biology, pharmacology, and pharmacy. Basic research (cell biology, pharmacology, pharmacy, biochemistry, molecular biology) accounts for a comparatively larger proportion of Chinese publications. Chinese neurosurgeons have performed comparatively little clinical research such as neurosciences, neurology, and surgery

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As for Chinese publications, basic research areas such as cell biology, pharmacology, pharmacy, biochemistry, and molecular biology represent a higher proportion of publications compared with other countries. Clinical research areas such as neurosciences, neurology, and surgery are underrepresented among Chinese publications compared with the rest of the world (Fig. 5).

International collaborative research

Among 10,770 Chinese publications, 9385 are articles (not including reviews, meeting abstracts, letters and editorial materials). The studies by Chinese neurosurgeons represent collaborations with researchers from more than 20 countries, mostly developed countries such as the United States, Japan, Canada, Britain, Germany, and Australia (Fig. 6).

Fig. 6
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The countries collaborating with Chinese neurosurgeons on publications

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The citation report from these 9385 articles is displayed in Table 4. Among the 9385 articles, 2393 were the products of international collaborations. We find that these collaborative publications have a greater impact factor than the overall average impact factor. The average Citations per Item across all Chinese publications in this sample is 8.23, while the collaborative publications’ Average Citations per Item is 15.46. The h-index of all publications (85) reflects the fact that nearly 7000 of these articles do not include statistics. The h-index for the collaborative publications (76) was not significantly reduced. Overall, these results suggest that the collaborative publications have a higher average quality.

Table 4 Citation report of all China neurosurgeon’s publications and cooperation publications
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Discussion

For historical reasons, Chinese neurosurgeons have only recently begun to publish their work in English language publications. Compared with foreign neurosurgeons, Chinese neurosurgeons have not historically published prolifically. With China’s development, the health care system in China has entered a new era. Chinese physicians need to update their knowledge to remain consistent with global trends, and they also want to share their findings with the world. Publications represent the ideal medium for these communications, and Chinese doctors have recognized this point.

The research output of Chinese neurosurgeons has increased every year, with a growth rate obviously higher than the worldwide average. The proportion of neurosurgical publications with Chinese authors has increased to 13 %, second only after the United States (35 %). Both the quality and quantity of Chinese research has improved, facilitating exchange with neurosurgeons all over the world.

This study highlights the great gap in neurosurgery between China and developed countries. While clinical practice research is an important area of research (neurosciences, neurology, and surgery) for neurosurgeons throughout the world, this research area represents a weak point for Chinese neurosurgeons. In real clinical work, Chinese neurosurgeons also follow guidelines from developed countries. Each country’s clinical practice has its own features, and issues with the implementation of clinical practice guidelines must be taken into account [11, 12]. Chinese neurosurgeons should develop guidelines in line with their evidence combined with their social and cultural environment [13]. This calls for increased attention to clinical research in the future.

China presents several advantages for clinical research. China has the largest population base, the largest pool of disease cases, and the largest group of neurosurgeons. Chinese clinical research results should be credible and widespread because of the large number of Chinese neurosurgeons. Meanwhile, we should maintain our strength in basic research, as these research results can be translated into clinical practice.

Chinese authors have infrequently published in the classic neurosurgical journals such as “Journal of Neurosurgery” and “Neurosurgery”. To solve this problem, Chinese neurosurgeons need to target these journals with the aim of allowing more foreign counterparts to understand what Chinese doctors have done. Although there are a few neurosurgical journals in China, they are all published in Chinese and can only be read by Chinese readers. A direct way to expand the influence of Chinese neurosurgery is to build China’s own neurosurgical publication platform. “Chinese Neurosurgical Journal” is the first Neurosurgical journal published in English in China. There is no doubt that “Chinese Neurosurgical Journal” will play an important role in introducing Chinese studies to the world.

Capital Medical University and Fudan University are the leading Chinese organizations in this field, mainly because these two universities have very well-known neurosurgical centers, such as the neurosurgical departments in Tiantan Hospital [14] and Huashan Hospital [15]. Bei**g Neurosurgical Institute (number 3 in the list) is also set in Bei**g Tiantan Hospital and has many links with Bei**g Tiantan Hospital. The list of organizations shows that most of the organizations are in central cities of eastern China, reflecting China’s vast territory and unbalanced development.

China presents several advantages for clinical research. China has he largest population base, the largest pool of disease cases, and the largest group of neurosurgeons. Chinese clinical research results should be credible and widespread because of the large number of Chinese neurosurgeons.

Neurosurgeons play an unparalleled role in the development of brain research. Neurosurgery is a rapidly develo** field of research, and now that Chinese neurosurgeons have begun to play a major role in this field, they should seize the opportunity and continue to publish important basic and clinical research in top journals in the field.

Limitations of this study

While the Web of Science is an excellent database, it has several limitations. Web of Science is an English-language database, containing very little literature in other languages. This may lead to a selection bias.

Another limitation comes from scientometrics and bibliometrics. The statement that “no one metric can fully capture the complex contributions scholars make to their disciplines”[16] highlights the deficiencies of the journal impact factor (JIF) [17]. There is a growing view that for greater accuracy, the JIF must be supplemented with an article-based assessment and peer-review [18]. Therefore, this study valued article-based citations rather than the journal impact factor.

Conclusion

While Chinese neurosurgical publication has made great progress, there is still significant room for improvement. The next step is to strengthen Chinese neurosurgical clinical studies and to improve the publishing environment of Chinese neurosurgeons in an effort to introduce the results to the rest of the world.