- Analytic perspective
- Open Access
Chinese journals: a guide for epidemiologists
Emerging Themes in Epidemiologyvolume 5, Article number: 20 (2008)
Chinese journals in epidemiology, preventive medicine and public health contain much that is of potential international interest. However, few non-Chinese speakers are acquainted with this literature. This article therefore provides an overview of the contemporary scene in Chinese biomedical journal publication, Chinese bibliographic databases and Chinese journals in epidemiology, preventive medicine and public health. The challenge of switching to English as the medium of publication, the development of publishing bibliometric data from Chinese databases, the prospect of an Open Access publication model in China, the issue of language bias in literature reviews and the quality of Chinese journals are discussed. Epidemiologists are encouraged to search the Chinese bibliographic databases for Chinese journal articles.
The Chinese have had a long history in infectious disease control, and records of epidemics can be traced back two millennia . Since the introduction of modern medicine by missionary doctors in the 19th century , modern epidemiological studies have been conducted in China, first by Western doctors, and then gradually superseded by their Chinese colleagues in the 1930s . Since the 1950s, huge reductions in the incidence of infectious diseases like measles and schistosomiasis have been achieved through national vaccination programmes and environmental intervention programmes [1, 4]. The adoption of the Open Door Policy in 1978 marked the beginning of remarkable social and economic development unprecedented in China's modern history. However, rapid industrialization and urbanization are accompanied by many social problems, from the increasing rich-poor, urban-rural, coastal-interior disparity to heavy environmental pollution. Changes in disease profile with the increasing burden of non-communicable diseases as a result of an aging population with a successful one-child policy posed new challenges in the 21st century . The SARS epidemic in 2003 exposed how a lack of transparency and delayed dissemination of information on the part of the Chinese government made an epidemic of then unknown aetiology a global problem .
Epidemiologists from the non-Chinese world may wonder what resources of scientific knowledge and epidemiological information China (whose health research serves a fifth of the world's population) may offer us. In 1994, the British Medical Journal published an editorial recommending to its readers the Chinese medical journals . However, 13 years have gone by, and the Chinese medical and scientific literature is still largely terra incognita outside China . Recent enthusiasm among Westerners in learning the Chinese language [7, 8] may rekindle their interest in this untapped resource. As Beijing prepares for the Olympics in 2008 celebrating China's arrival in the modern world, perhaps an update of the development of Chinese biomedical journals may whet the reader's appetite. This paper is intended to serve as a guide.
This article will first provide a general overview to Chinese biomedical journals. Next, Chinese bibliographic databases will be described, using Wan Fang and iLib as examples. Chinese journals in epidemiology and public health will then be discussed, followed by a comprehensive examination of issues arising from switching the publication language to English, the effect on impact factors and Open Access. Lastly, the problems of language bias and quality of articles will be discussed. Three appendices are included. Appendix 1 provides additional information on bibliographic indexing of Chinese biomedical journals. Appendix 2 illustrates the historical background to the choice of language of publication using three journals as examples. Appendix 3 is a review of a survey of English language biomedical journals of China previously published in a Chinese journal.
For the purpose of this study, Chinese journals and databases discussed here are confined to that of mainland China, excluding Hong Kong, Macau and Taiwan. For a more in-depth study of the research potential of Chinese biomedical bibliographic databases, illustrated by the example of schistosomiasis research, please refer to the paper in this thematic issue by Liu et al. .
Chinese biomedical journals: an overview
Today there are more than 5000 academic periodicals published in mainland China, and around a thousand of these are related to biomedicine and health. Seventy-four journals from mainland China were indexed in 2006 Journal Citation Reports® Science Edition (JCR) published by Thomson Scientific, of which 12 were biomedical journals and two were multi-disciplinary science journals that publish biomedical articles. Of these 14 journals, only one was published in Chinese, while the rest were in English.
Eighty-two mainland Chinese journals are indexed for MEDLINE [10, 11], among which, 62 publish articles in Chinese, 16 in English, one in either English or German, and three in either Chinese or English. Only six of the MEDLINE-indexed mainland Chinese journals receive impact factors from JCR. All six publish articles in English (Table 1).
Altogether, 146 mainland Chinese journals that cover subjects such as general science, biology, medicine, veterinary science, agriculture and forestry, are indexed in the PubMed journal database (some of these are indexed in MEDLINE). Of these 146 journals, 110 publish articles in Chinese, 24 in English and seven in either Chinese or English (with one in Chinese or Latin and one with missing language data). For a detailed discussion, please refer to Appendix 1.
Searching for Chinese articles: the bibliographic databases
Full texts of more than five thousand Chinese journals are now available online. There are six mainland Chinese bibliographic databases through which Chinese language biomedical journal articles can be searched and located and of which two provide English interfaces:
Chinese Biomedical Literature Database (CBM) ,
Chinese Medical Current Content (CMCC) ,
VIP Information (VIP) ,
Users of traditional Chinese characters can use Yahoo! Taiwan Academia Search  whose mainland Chinese journal article entries are provided by iLib. In addition, Google Scholar [21, 22], as a multi-lingual bibliographic database, also facilitates searches in the Chinese language (Table 2)
As a recent paper  has given a detailed description and analyses of five of the Chinese bibliographic databases, the following discussion is restricted to three of them: Google scholar as related to searches in Chinese has not yet been covered by any academic paper in English and the same is true of iLib, which is not covered by ; Wan Fang database, which is freely available through terminals in the British Library, will be used as an example to illustrate the wealth of biomedical journals available to us through the internet.
Google Scholar provides a convenient starting point for searching Chinese articles, of which the bibliographic data is mainly provided by VIP information, Wan Fang database and iLib (all accessed on 21st February, 2007). For Chinese speakers, Google Scholar also provides a Chinese interface .
There are two apparent advantages (especially for non-Chinese speakers) of searching for Chinese articles in Google Scholar. Firstly, Google Scholar (Chinese interface) provides 'pinyin search', i.e. using a standardised Romanised form of Chinese, known as pinyin in Chinese . For example, if I type 'bing du' in the Google Scholar English interface, I will obtain journal articles with authors of the family name Bing Du. However, if I use the Chinese interface, I will be prompted whether I actually want to search with the search term (virus; bing du in Chinese pinyin). If so, by clicking on the prompt, I will be able to get my results for virus in Chinese. Secondly, it supports an automatic interchange between simplified Chinese characters used in mainland China, Malaysia and Singapore and traditional Chinese characters used in Hong Kong, Macao and Taiwan. These two functions are unique to Google Scholar at the moment and are not supported by the other Chinese bibliographic databases.
In additional to these functions, Google Scholar also provides links to institutional libraries and the British Library, citation records, links to related articles, and it groups different entries of the same article together. For a more structured search, the Advanced Scholar Search is needed, of which a Chinese interface is also available .
As of 13th February 2008, the Chinese links in Google Scholar provided by VIP information are linked to the PDF full text which requires subscription to VIP information. If the user is not covered by subscription, the link will be redirected to the webpage on which the title, author, abstract and keywords (all in Chinese) are displayed. The full text can then be purchased individually. Chinese links in Google Scholar provided by the Wan Fang database and iLib will directly lead to the Chinese abstract page. From there a link is provided to the full text PDF file which requires payment or subscription.
Although a previous study performed in 2005 found an English language bias in Google Scholar , the search engine has evolved so quickly that a new study of its article coverage is definitely worthwhile.
Wan Fang and iLib
Both Wan Fang database and iLib are run by Wanfang Data, an affiliate of the Chinese Ministry of Science & Technology (cf. ). While Wan Fang provides access to databases of journal articles, conference proceedings, degree theses, patents, national and industrial standards and even listed companies in China, iLib is essentially a subset of Wan Fang and is restricted to journal articles only.
The Wan Fang database maintains two portals, one in Chinese  and one in English . Cross-searches of different databases (e.g. journal articles and conference proceedings) using simplified Chinese in the domestic portal and English in the international one, are available.
Searching in iLib and Wan Fang
The advantage of iLib over Wan Fang for journal article searches is that the interface of iLib is more user-friendly and, unlike Wan Fang, there are links to the author, the journal issue, the journal, the references cited in the paper and some related papers in the iLib database, similar to the AbstractPlus format of PubMed.
Like PubMed, the Wan Fang databases or iLib can be searched for free. However, only Chinese abstracts are available for free in HTML format. Although many Chinese journals provide English abstracts to their articles nowadays, these English abstracts are not uploaded onto the public domain by Wan Fang or iLib. To access the English abstract online, one has to download the PDF full text which requires subscription. The only exceptions are those indexed by PubMed, through which they are freely available.
A difference in the search mechanism is that in Wan Fang, one has to choose whether to search the English Online Journals category or the China Online Journals (Chinese language journals) in the first place, while in iLib, there is no separation of the journals by language. Thus, if one types 'influenza' in iLib, one will find articles published in Chinese language journals (as the English titles of the Chinese articles are actually being searched) as well as in English language journals.
Subscription or payment for full text of mainland Chinese journal articles
For individual users, there are various methods of payment. However, most (if not all) of these methods apply only to users in mainland China. While VIP information accepts VISA card online payment, Wan Fang and iLib do not accept any credit cards; they accept only bank cards issued in mainland China or payment through a mainland Chinese mobile phone company, remittance via post offices or banks, or some 'pay-as-you-download cards', which provides you with a password to top-up your download credit online, using your personal Wan Fang or iLib account.
The British Library
To the knowledge of the author, as of 14th February 2007, the British Library has subscriptions to full text (PDF files) of all academic journals (both English language journals and Chinese language journals) available in the Wan Fang database (around 5700 periodicals). Readers have access to these journals through the computer terminals in the library. Below I describe in more detail what is available in the Wan Fang database.
English language journals in the Wan Fang database
There are 141 titles under the category of English China Online Journals. According to Wan Fang categories, eight are on agriculture, 58 on fundamental science, 24 on health and medical science, 48 on science & technology and three on social science, as of 14 August 2007 . Table 3 lists 24 English language journals on health and medical science available in Wan Fang. A full list in alphabetical order is available in .
Chinese language journals in the Wan Fang database
Under the category of China Online Journals, there are more than 5600 titles (5638 as of March 2007). When subdivided into five categories, over a thousand titles are found to be related to health, medicine and biology (1056 as of June 2007) .
Currently, it is the Chinese national standard that scientific periodicals published in mainland China in the Chinese language should contain English abstracts for every original research article and English titles for selected important articles (e.g. editorials, reviews, forums and short research articles, depending on the judgement of the editorial board) . The English table of contents is available online, free of charge, through the Wan Fang database. However, the English abstracts are only available in the full text PDF file from the Wan Fang database that requires subscription. (Only the Chinese abstract is available freely online in HTML format.) Thus, if one is unable to read Chinese, then his/her search is limited to 'Titles' and 'Authors' for the articles required. A new approach must be adopted if Chinese scientific journals aspire to secure a wider readership and a higher citation rate. Since the Scientific Electronic Library Online  can provide free online access to English abstracts of Spanish and Portuguese journal articles, it would seem appropriate for the Wan Fang database to move towards a similar standard. Of course, English abstracts are available for journals indexed by PubMed or ISI Web of Science.
Chinese journals in epidemiology and preventive medicine
Here, I introduce journals that are of particular interest to epidemiologists. The top general medical journal in mainland China is the Open Access English semi-monthly Chinese Medical Journal , abbreviated as Chin Med J (Engl) or the CMJ, and its sister periodical in Chinese, Zhonghua Yi Xue Za Zhi, the National Medical Journal of China. Both are MEDLINE-indexed. The CMJ has an impact factor (2006) of 0.615 (Table 1) (For the history of CMJ, please refer to Appendix 2.)
There are 105 journals under the category of "Preventive medicine and hygienics" in the Chinese portal of the Wan Fang database and in iLib [34, 35] as of 21 February 2007, which covers journals in epidemiology, preventive medicine, occupational health, toxicology, health economics and hospital management.
Chinese core journals and VIP impact factor
A few pieces of data can help us evaluate the quality of these journals. Although Science Citation Index Expanded and MEDLINE are primarily bibliographic databases with their main purpose being to search scientific and medical literature, they are sometimes used as pointers to indicate journals of importance. However, as language bias is suspected among these English-language indexing services, it is important to look at the data produced by the Chinese themselves. Among the 5000+ Chinese journals, some are classified as 'core journals'. According to Sun , these are indexed by at least one of the following three indexing systems. The first one is Comprehensive Lists of Titles of Chinese Core Journals (zhongwen hexin qikan yaomu zonglan) published by The National Library of China every four years. The latest one was published in 2004 which is available at  (username: gjtsg; password: tsgbkb; provided by National Library of China, see ). Its function is similar to that of MEDLINE: to indicate which are the top journals for a given field. It takes into account the bibliometric data from 52 databases or abstracting services, awards given by the national General Administration of Press and Publication, indexing by important indexing services (both national and foreign) as well as qualitative peer-review by specialists in the disciplines. In Tables 4, 5 and 6, those journals that were indexed in the Comprehensive Lists 2004 are indicated as 'Chinese core journals 2004' accordingly. The other two 'core journal' databases are the Chinese Science Citation Database  managed by the Chinese Academy of Science, and the Chinese Science and Technology Paper Citation Database managed by The Institute of Scientific and Technical Information of China (cf. [6, 26]).
Apart from impact factors published by Thomson Scientific in JCR, VIP Information also publishes bibliometric data of some of the journals indexed in its database . A handful of journals listed in Table 4 have their VIP impact factor and immediacy index available, which can contribute towards evaluation of their quality.
Two tiers: national and provincial
Table 4 lists 21 journals in epidemiology, preventive medicine and public health. These journals can be divided into two tiers: national and provincial. The Chinese Journal of Epidemiology and the Chinese Journal of Preventive Medicine (both published by the Chinese Medical Association (CMA)), and Journal of Hygiene Research (published by the Chinese Center for Disease Control and Prevention (China CDC)), represent the best research outputs of the disciplines in mainland China. They are indexed by Medline and Chemical Abstracts.
Other national journals include CPMA journals, like the China Preventive Medicine and the Chinese Journal of Public Health, and the International Journal of Epidemiology and Infectious Disease (formerly entitled, Foreign Medical Sciences (Epidemiology and Infectious Disease)) of CMA .
Of 31 provinces, autonomous regions and municipalities of the People's Republic (excluding the Special Administrative Regions of Hong Kong and Macao), only 12 publish their own journals of preventive medicine (Table 4) . Among the five Chinese core journals listed in Table 4, only Modern Preventive Medicine is a provincial journal. Three provincial preventive medicine journals received a VIP impact factor: that of Henan and Jiangsu as well as Gonggong Weisheng Yu Yufang Yixue of Hubei (Table 4). The others are trying hard to 'catch up'. For example, the Journal of Applied Preventive Medicine (new title since 2006, Volume 12 issue 3; formerly entitled, Guangxi Journal of Preventive Medicine) from Guangxi Zhuang Autonomous Region in southern China now has an international board of editors .
The development of the internet has prompted a drastic change in the ecology of academic publication worldwide and Chinese journals are no exception. Some observers may note that the purpose of publishing provincial journals may be to present epidemiological findings mainly of local use and serve as a local publication outlet. However, as all of these journals are now available online, the original raison d'être of provincial journals to foster the exchange of research output on a provincial level may diminish. A doctor from Sichuan can now easily download a paper published in the Shanghai Journal of Preventive Medicine, while a scientist from Guangzhou (Canton) can easily publish his/her paper in the Zhejiang Journal of Preventive Medicine. One can imagine fierce competition for good research papers among these journals in the near future and through the invisible hand of the market, some journals may prosper and attain international status while others may wither and die.
An interesting exception to the two tiers of national and provincial journals is the Journal of Preventive Medicine of Chinese People's Liberation Army, in which research articles related to public health issues in a military context, from hygiene in training camps to the temperature inside tanks, are published. Apart from those, there are also articles on civilian public health issues written by scientists in the military academy.
Specialist journals relevant to epidemiologists
Table 5 lists 23 journals related to tropical medicine, including journals in parasitology, HIV and tuberculosis. Table 6 lists 23 journals on non-communicable diseases, medical statistics, school health, occupational health, port/frontier health and quarantine, evidence-based medicine and reproductive health and family planning. All but one are published in Chinese. The exception, the Journal of Reproduction and Contraception is published in English with a sister publication, Reproduction and Contraception, published in Chinese . Some of these journals have been listed as Chinese core journals in 2004: three in parasitology (Table 5), one in medical statistics, one in school health, five in occupational health and two in reproductive health and family planning (Table 6). Specialist national journals like the Chinese Journal of Parasitology and Parasitic Diseases, of the Chinese Preventive Medicine Association (CPMA) series , publish papers of high academic standard in their respective specialties.
Articles of epidemiological relevance may also be found in medical university journals. It is common among mainland Chinese universities to publish university journals that contain predominantly their own research outputs. These journals number around 2000 in total, of which nearly half belong to natural sciences . University journals published by medical universities or medical faculties of comprehensive universities cover the whole spectrum of medical specialities. Some are indexed in MEDLINE, like the Journal of Peking University (Health Sciences) (cf. Table 1). The performances of 41 of these medical university journals have been analysed recently  and they varied greatly. Reform proposals have been suggested .
Switching to English: Opportunities and pitfalls
More and more Chinese language biomedical journals now accept submission of English articles (with Chinese abstracts). Some are even considering switching to English completely, e.g. the Journal of Molecular Biology . According to Zhang et al. , over 200 English language academic journals have been published in China from 1929 to July 2001. Out of these, more than 150 are published by "universities or institutions" in China . Compared to Taiwan and Hong Kong, the share of mainland Chinese academic journals published in English is relatively small. As illustrated by the history of three flagship general medicine journals in greater China (see Appendix 2), socio-political factors often play a role in the choice of language of publication used by a journal. While biomedical journals in Hong Kong have always been published in English due to its British colonial legacy, Taiwanese journals have been switching from Chinese to English in the recent quarter century. My hypothesis is that, due to Taiwan's small population, the internal market for its journals is small. Given that mainland Chinese and Hong Kong readers are unlikely to read Taiwanese journals, these journals switch to English to gain a wider readership (cf. The Journal of the Formosan Medical Society, see Appendix 2). Their situation is not unlike that of journals published in some small European countries . On the contrary, in mainland China, with its huge population and considerable number of scientists and medical professionals, the internal market for biomedical journals is substantial enough to sustain a sizable number of Chinese language journals. Thus I suggest that the size of the prospective market (as a result of the linguistic and political divide) plays a significant role in shaping the language trend of the world's journal publication.
Through the international language of scientific communication, English language journals provide a platform for Chinese (and foreign) scientists with a broad international readership. Hopefully, some of these journals will manage to receive their impact factors from JCR. However, by switching to English and internationalising their scope (e.g. by dropping the word 'Chinese' from their titles), they face severe competition from their counterparts in North America and Europe. Nevertheless, there are a few successes so far, like Cell Research and the World Journal of Gastroenterology: WJG  that are now indexed in Science Citation Index Expanded and MEDLINE. As the Chinese share of the world's scientific output increases and as Chinese scientists become more fluent in English, more English language biomedical journals published in China will receive their limelight in the international arena. For further discussion, please refer to Appendix 3.
Towards a truly global impact factor?
The increasing trend of using impact factors published by Thomson Scientific as an indicator in academic evaluation in universities and research institutes has received much criticism from non-English-speakers of the developing world . One of the criticisms against it is the alleged language bias of the Thomson Scientific database coverage towards journals published in English and in the industrialised world [51, 52]. The 'what-if' scenarios of inclusion of non-Science Citation Index (SCI)-indexed journals upon the impact factors of SCI-indexed journals have been studied and the 'hypothetical' impact factors of the non-SCI-indexed journals calculated [52, 53]. In order to better evaluate the performances of Latin American journals, SciELO publishes bibliometric indices of its own, similar to that of Thomson Scientific, using data from its database which reflect more the regional context . Brazilians can now evaluate their journals using the SciELO impact factor, rather than relying solely on that published in JCR . Should the Chinese do the same? At the moment VIP Information publishes bibliometric indices using data from its own database  (cf. Table 4). These data should be used in our evaluation of the quality of Chinese journals, especially in our fields of epidemiology and public health, as hardly any of these are indexed in Thomson Scientific database. Currently only a sub-set of Chinese journals receive their impact factors from VIP Information. Hopefully, in the future, more journals will receive their bibliometric data, perhaps not only from VIP Information alone, but pooling data from the other Chinese databases as well. In the long run, I envision an international collaboration between Thomson Scientific, SciELO, the Chinese databases and other bibliographic databases to provide authors and editors alike with a more accurate and comprehensive bibliometric data of journal performance by collating data across the various databases.
Open Access (OA) online publishing in China falls into two categories: non-peer-reviewed and peer-reviewed . The former provides an online interface for authors to publish their papers directly online, without peer-review or other form of quality control. Examples include Qiji.cn , the Chinese Preprint Service System  and Sciencepaper Online . The latter transfers paper-based peer-reviewed journals onto the web for free access (usually in PDF format). The Alliance of open access journals (OAJs) , sponsored by the Society of China University Journals in Natural Sciences, provides access to a number of OA journals, predominantly Chinese university journals. The international Directory of Open Access Journals (DOAJ)  also provides links to the websites of individual Chinese OA journals, including the Chinese Medical Journal .
However, to date the proportion of mainland Chinese journals adopting the OA publishing model is small. One possible reason is that Chinese bibliographic databases, unlike their Western counterparts, provide subscribed readers with PDF full text on behalf of the journals at an affordable rate – CNY three yuans (equivalent to USD 39 cents, as of 17 August 2007 ) per paper. Thus, the cost of setting up and maintaining an individual website for a journal may seem to be a potential financial disincentive. Furthermore, most OA journals, like that of BioMed Central  and Public Library of Science , adopt an author-pay model. In the mainland Chinese context where research funding is inadequate, more often than not, authors are less willing to pay for publication in OA journals. While OA journals in the West can grant waivers to authors from low income countries because their overhead costs are met by membership fees and article processing charges paid by universities and authors from the West, for most Chinese journals this will be difficult as most of their authors come from mainland China.
However, there are reasons to believe that many mainland Chinese authors welcome the development of OA publishing . Given the current limited accessibility of full text Chinese journal articles from outside China, OA journals may prove to be an option for rapid scientific communication between authors and readers from within China and without.
Why bother after all?
One may ask why bother with Chinese journal articles after all. Apart from those who do field work in China, what important epidemiological information does the Chinese literature offer us?
Avoid language bias
Perhaps one important application is to avoid language bias in our literature reviews . Back in 1995, Grégoire et al.  found that among the 36 consecutive meta-analyses that they analysed, one would produce a different conclusion had it not excluded studies based on linguistic reasons. Comparing English and German journals, Egger et al.  found that randomised controlled trials (RCTs) were more likely to publish in English language journals if they gave statistically significant results. This led to the worry that language bias could be introduced to reviews and meta-analyses restricted to data published in English, leading to distorted results. However, subsequent studies [68–70] found little evidence supporting this assertion. Pham et al. found that language bias led to an under-estimation of the protective effect of intervention in RCTs in complementary and alternative medicine (CAM) systematic reviews but not in that of conventional medicine .
Regarding the quality of reports, trials and systematic reviews published in English and those in languages other than English (LOE), are similar [71–73]. Inclusion of studies published in LOE in systematic reviews and meta-analyses is "likely to increase precision and may reduce systematic errors" , but financial budget and time constraints should also be taken into account .
Quality of articles
The quality of articles published in Chinese medical journals has led to debates in Western academia. The conclusion of a recent systematic review on the clinical effectiveness of treatment with hyperbaric oxygen for neonatal hypoxic-ischaemic encephalophathy that the "Chinese medical literature may be a rich source of evidence to inform clinical practice and other systematic reviews"  was disputed. In an online rapid response, Peter C. Gotzsche ("No double standards in research, please" dated 26th August 2006) argued that Liu et al. had provided no evidence for their statement. The standard adopted by Cochrane and CONSORT by which the Chinese trials identified in  are judged to be of poor quality, are not "Western" as declared by Liu et al. since they are adopted internationally, including by the Chinese Cochrane Centre. Gotzsche also cited two reviews [74, 75] to argue that "Chinese trials are far more positive, on average, than trials performed in other countries". In another study, Wang and Zhang found that by 1995, the "frequency of using statistical tests in Chinese medical journals appears comparable to that in other parts of the world", but "the lack or inappropriate use of statistics remains a problem" .
In spite of this scepticism, the present author agrees with Smith that Chinese medical journals are "a treasure house of medical science available for explorers"  provided that we evaluate the evidence published therein with no double standard. There are examples of reviews that cover Chinese journals and evaluate the evidence available, e.g. in a recent review on the effectiveness of hand-washing in preventing SARS, among the ten case-control studies identified, four were published in Chinese journals .
Chinese journals are a mine of epidemiological information that is yet to be explored by the outside world. Thanks to the development of the internet and bibliographic databases, they can now be explored with relative ease. It has been suggested that in order to be comprehensive, we should apply LILACS in our literature search to cover Spanish and Portuguese articles in our systematic reviews [78, 79]. Perhaps it is time to add to our list the Chinese databases and also include Chinese papers.
Appendix 1 Chinese biomedical journals indexed in bibliographic databases
In 1990, Gastel and Weng  published a detailed overview of Chinese medical journals written for Western readers. At that time, the number of medical journals published in China was estimated to be 500, rising to 700 only four years later . In 2007, around 1000 titles related to biomedicine and health, from more than five thousand academic periodicals, were published in mainland China. To see this in a bigger picture, let us take Journal Citation Reports® (JCR) and MEDLINE as bench marks.
Seventy-five journal titles from mainland China were indexed in 2006 Journal Citation Reports® Science Edition published by Thomson Scientific (compared to 17 from Taiwan and one from Hong Kong), among which the Journal of Integrative Plant Biology is the new title (since 2005) given to the journal formerly entitled Acta Botanica Sinica. Among these 74 mainland Chinese journals, there were 12 biomedical journals and two multi-disciplinary science journals that publish biomedical articles. Of these 14 journals, only Progress in Biochemistry and Biophysics is published in Chinese and the rest are in English. (Note: Acta Pharmacologica Sinica publishes in English according to MEDLINE but JCR 2006 records it as multi-lingual.)
As of 30th September 2006, 20,800 serial titles were received by the National Library of Medicine, the largest medical library in the world . As of January 2007, 5164 journals were indexed for MEDLINE , of which 82 were mainland Chinese journals (including Shen Jing Ke Xue Ton Bao and Zhen Ci Yan Jiu which were newly added to MEDLINE in February 2007 ) (Data as of 28th June 2007) (Table 1). Among these mainland Chinese journals, 62 publish articles in Chinese, 16 in English and three in either Chinese or English. One exception is the Journal of Huazhong University of Science and Technology (Medical Sciences) which publishes mainly in English but with some articles in German. This was because of the historical link of Tongji Medical College (which is now part of Huazhong University of Science and Technology) to Germany. (Note: According to MEDLINE record, it publishes in English only.) Only six of the MEDLINE-indexed mainland Chinese journals receive impact factors from JCR (Table 1). All six publish articles in English. Among them, Cell Research receives the highest impact factor of 3.426, followed by the Asian Journal of Andrology (1.737) and Acta Pharmacologica Sinica (1.397).
If we relax our criterion and include non-MEDLINE-indexed journals in our analysis, there are 146 mainland Chinese journals (of general science, biology, medicine, veterinary science, agriculture and forestry) indexed in the PubMed journal database (for details of data analysis, see below), of which 110 publish articles in Chinese, 24 in English and seven in either Chinese or English (with one in Chinese or Latin and one with missing language data).
Wan Fang database
As of June 2007, there are 1056 Chinese journals in the field of health, medicine and biology according to the English portal of Wan Fang database . 985 titles fall in the category of yiyaoweisheng (: Medical, pharmaceutical and hygiene/health) as of 7th August 2007, according to the Chinese portal of Wan Fang database .
On 21st November 2006, the PubMed journal database was searched with the following search terms: China OR Chinese OR Zhongguo OR Sinica OR Taiwan OR Taiwanese OR Taiwanica OR Formosa OR Formosan OR Hong Kong. A resulting 270 titles were obtained. By eliminating titles that have ceased to publish and those that are irrelevant to biomedical, veterinary and agricultural sciences, there were 179 titles. Putting aside the Taiwanese journals and those of Hong Kong, Macao and other countries/territories, there were 146 mainland Chinese journals (including those published by foreign publishers and thus registered the country of publication of its publisher). There were a few records whose country of publication data were missing or mistaken and were corrected for in the analysis.
According to a recent study , from 1932 to 2005, there were 1093 journals (537 titles current in 2005) from greater China, including Hong Kong (n = 7, 0.6%) and Taiwan (n = 58, 5.3%) indexed in Chemical Abstracts, among which 51 (4.7%) belonged to biological sciences and 216 were health-related (yiyaoweisheng), i.e. category Q and R according to the Chinese Library Classification . English language journals made up of 9.7% (n = 106) of the total. The majority of the journals indexed were established in or after 1980 (69.2%). The first journal being indexed was Chinese Medical Journal (see Appendix 2). Up to 14th October 2005, a total of 693610 articles had been indexed. A full list of the indexed journals with their ISSN, indexed years and number of indexed articles can be found at .
Up to 16th January 2006, a total of 340 journals, with 333621 articles, published in China have been indexed in Scopus, among which 73 (21.5%) titles are English language journals. According to the Chinese Library Classification, seven (2.1%) of the 340 indexed journals belonged to biological sciences (category Q) and 33 (9.7%) were health-related (yiyaoweisheng, category R). Comparing this to other bibliographic databases, 58 of these 340 journals were also indexed by Thomson Scientific, 264 by Wan Fang database and 280 by VIP Information. A full list of the journals indexed in Scopus with a detailed analysis can be found at Bao .
Appendix 2 History and Language: A case study of three flagship general medical journals in greater China
The purpose of this appendix is to illustrate how the historical background of a geopolitical region influences the choice of language of publication of a biomedical journal. I have chosen as examples, the three flagship general medical journals in greater China, namely, the Chinese Medical Journal, the Journal of the Formosan Medical Association and the Hong Kong Medical Journal. These journals provide a vivid illustration of how the decision to publish in Chinese or English is influenced by socio-political factors.
Chinese Medical Journal
The Chinese Medical Journal (CMJ) is the oldest English medical journal published in China. Its history can be traced to the China Medical Missionary Journal , founded in March 1887 in Shanghai by the China Medical Missionary Association () to foster the exchange of experiences and information among Western medical missionaries who worked in Christian hospitals in China. It was renamed Chinese Medical Journal in 1907. In November 1918, the Chinese Medical Association () was founded and started to publish a bilingual National Medical Journal of China (). In January 1932, the Chinese Medical Journal and the English section of the National Medical Journal of China merged and became the new Chinese Medical Journal ().
During the Second World War, the normal publication and distribution of the Chinese Medical Journal had been interrupted. Three versions of the journal had been published to serve three different readerships: the Japanese-occupied region by the Shanghai version (1942–45), the Free China by the Chengdu version (1942–44) and overseas by the Washington D.C. version (1943–44). Normal publication resumed in Shanghai in 1946 (volume 64).
After the establishment of the People's Republic, the Chinese Medical Association moved from Shanghai to Peking (Beijing) in 1951. Since then the Chinese Medical Journal has been published in Beijing. During the Cultural Revolution, the publication of the CMJ was interrupted. It was re-named China's Medicine (1966–68). Its publication ceased in 1969 and was re-established as the Chinese Medical Journal in 1975 (Note).
In 1979, following the Open Door Policy, a new editorial committee was formed and the CMJ resumed its academic vigour and quality as the flagship journal of the Chinese Medical Association, a window for the world of the achievements of the Chinese medical profession.
For many years, the CMJ had been the only English medical journal published in China, amidst many other journals published in Chinese. From its inception as a journal founded by Western doctors for their own medical communication, it has become the bridge for the Chinese medical profession to communicate their research outputs with the outside world. Henceforth, the use of English by the CMJ, should be interpreted as a deliberate act on the part of the Chinese to communicate cross-culturally to the rest of the world. (A brief history of the Chinese Medical Journal, written in Chinese, can be found on the CMJ website .)
Note: The year 1975, as the date of resumed publication of the CMJ, is correct according to the CMJ website  and the British Library Integrated Catalogue . However, one can find evidence among American medical literature that the CMJ resumed publication in January 1973 as volume 1 number 1 . Obviously this was warmly welcomed in the West as a sign of the Chinese medical profession going back to normal after the upheavals in the early years of the Cultural Revolution [89–93]. According to the British Library Integrated Catalogue, the CMJ was resumed published in January 1975 as volume 1 number 1. Since January 1979, the pre-Cultural Revolution sequence of volume number was resumed and the CMJ was continued at volume 92.
The Journal of the Formosan Medical Association
Taiwan had been under Japanese colonial rule from 1895 to 1945. The Journal of the Formosan Medical Association (, also known as ) was established in 1902 by Japanese doctors in Taiwan (also called Formosa by the Portuguese) and was first published in Japanese, with an English title Taiwan Igakkai Zasshi from 1931. From 1934, articles could also be written in European languages, like German. Its publication was interrupted in 1945 as the Second World War was drawing to a close. After the Second World War, when Taiwan was returned to the Republic of China, its publication resumed with Chinese language as the major medium. In 1987, it split into an English version and a Chinese version. In 1992, it switched to English completely and changed its English title from Taiwan I Hsueh Hui Tsa Chi to the current title. It has been indexed for the Science Citation Index since 1996. The Chinese version became Continuing Medical Education () in 1991 and Formosan Journal of Medicine () in 1996. It is published in Chinese to meet the needs of grass-roots medical practitioners .
Here, we observe the colonial footprint of the Japanese in the early history of Journal of the Formosan Medical Association. The end of Japanese rule brought an end to the use of Japanese among Taiwanese doctors. The decision to publish in Chinese coincided with the tide of decolonisation. The decision to split the journal into two, one in English for the publication of research output and one in Chinese for the continuing medical education at the grass-roots level, is a classic example of the dilemma between serving local needs and communicating research outputs to the world. (A Power-Point presentation of the History of the Formosan Medical Association and its Journal, written in Chinese, can be found at .)
Hong Kong Medical Journal
The Hong Kong Medical Journal ()  is the official journal of the Hong Kong Academy of Medicine and the Hong Kong Medical Association (HKMA) . Its history can be traced to the Hong Kong Chinese Medical Association (HKCMA), the predecessor of HKMA, which was founded in the British colony in 1920 . The society journal, the Bulletin of the Hong Kong Chinese Medical Association () was established in 1948 (Note) . As the HKCMA was renamed as HKMA in 1970, the Bulletin was renamed the Bulletin of the Hong Kong Medical Association () (volume 22 continues) , which was later continued by the Journal of the Hong Kong Medical Association (Chinese title unchanged) in 1985 (volume 37 continues) . It was superseded by the Hong Kong Medical Journal in 1995 (starting from volume 1). Articles are published in English with Chinese abstracts.
As in other former British colonies like India or Singapore, the colonial legacy of creating a class of bilingual elites in Hong Kong rendered local medical publication in Chinese unnecessary and the use of English as the medical language in Hong Kong removed the language barrier in international communication of the medical profession.
Note: Volume numbering of the Bulletin of the Hong Kong Chinese Medical Association started in 1948 as volume 1. It skipped publishing in 1950 and continued in 1951 as volume 3. Again in 1959, it skipped publishing and it continued in 1960 as volume 11 .
The above section illustrated how Chinese doctors adapt to changes in the socio-political arena by their choices of language of publication of their flagship general medicine journals. The Chinese Medical Journal, as the only English medical journal published in mainland China for many years, provided a showcase of Chinese medical achievement to the world and a channel of communication between Chinese doctors and their colleagues aboard. The Journal of the Formosan Medical Association demonstrated the process of colonisation, decolonisation and internationalisation in its switch of language from Japanese to Chinese and then to English. The Hong Kong Medical Journal is an example of how a colonial legacy has left a language heritage that fosters internationalisation in this globalising world.
The choice of language of publication by biomedical journals is often a consequence of many different socio-political factors.
Appendix 3 A survey of English language biomedical journals of China
A survey of English language biomedical journals published in China was conducted by Yu et al. in 2006 via self-administered questionnaires and interviews of their editorial boards . The survey covered 31 journals and gave a good summary of their basic information, bibliometrics, and details of their management, editorial board, publication and distribution. As this survey was published in Chinese with no English abstract available, and is therefore, less accessible to the average English-speaking readers, a review highlighting its major findings that are relevant to our present study will be of benefit to interested readers and is provided below.
While 19 of these 31 English language journals reported an adequate supply of submitted manuscripts, nine reported that theirs were inadequate (three did not reply to this question). Major reasons for this inadequacy were (1) dearth of scientific research output leading to dearth of manuscripts; (2) huge amount of high-quality manuscripts being drained to foreign journals; and (3) the limited capacity of writing in English on the part of some authors. The annual number of manuscripts received varied greatly (Table 7). Eighteen journals received manuscripts from outside China, ranging from a few manuscripts per year to 30% of its total number of manuscripts received. The majority of these submissions came from other developing countries. One of the consequences of low supply of high-quality manuscripts is that the frequency of publication of journals in China is low: 19 of the 31 English language journals are quarterly or semi-annual (Table 8) .
Another area that awaits improvement, according to Yu et al. , is the unequal distribution and non-specialisation of journals in China. Nearly half of the 31 English language journals surveyed are general medical journals, while there are no English language journals from China that are specialised in fields like epidemiology and preventive medicine. As it has been suggested , general journals should merge to raise their profile while others should specialise to avoid overlap in disciplines.
Among these 31 journals, the only full-time Editor-in-Chief is that of the World Journal of Gastroenterology: WJG. All the others work part-time for the journals. Yu et al.  argued that this was very disadvantageous to the development of these journals. The number of full-time editors varied across the 31 journals (Table 8), while 13 journals had additional part-time editors varying from one to six. Yu et al.  commented that in China, there are very few editors who have high academic qualifications in biomedical sciences and at the same time are proficient in the English language. More training is needed. In order to attract talent and prevent further brain-drain, Yu et al.  suggested that scientific editors in China should receive the same pay and benefits as scientific researchers to remove the impression that editors are second-class scientific professionals.
Twenty-four of the 31 journals received funding from the government; 20 had page-charges; six received remuneration from advertisements; six received sponsorship from the National Fund for Natural Sciences; and eight received sponsorship from other sources. Seven journals ran a deficit balance; 14 achieved breakeven and two made profits (no reply from eight journals). Given these disturbing facts, Yu et al.  suggested that while the Chinese government should increase its financial investment in these journals, the editorial boards should also learn how to manage the journals more efficiently.
International peer-review has been archived by thirteen of the 31 journals. Peer reviewers were drawn mainly from the West and Japan. Non-Chinese editors are found in eight journals. Apart from two Germans, they all come from English-speaking countries, and their number is limited to one per journal, with one exception which has three non-Chinese editors. All 31 journals studied are now online, of which eleven have their own websites. To different extents, they all manage their editorial process of submission, peer-review and re-submission electronically .
According to Yu et al. , the crux of the problem of journals in mainland China is that their model of operations remains that of planned economy, rendering them unfit to compete in today's Chinese market economy. As of 2006, eighteen of the 31 journals were distributed internationally, mainly through the agency of international publishing groups, like Elsevier, Nature, Springer and Blackwell. Through collaboration with these publishing groups, Chinese journals can benefit in terms of efficiency, economy of scales and share of the international market. Not only does this illustrate the feasibility of international collaboration, but it also provides Chinese publishers a model of development into a commercially viable publishing group of scientific periodicals. However, only seven of these 18 journals achieved an international circulation of more than 100 copies. This reflects the difficulty of breaking through into the international market.
Publishing in English is correlated to higher international visibility . Using data of 2003, Yu et al.  showed that English language biomedical journals of China were more likely to be indexed in international databases than their Chinese language counterparts (Table 9). However, compared to the international English language journals, their impact was rather low (as indicated by their low impact factor in JCR). Interestingly, by moving towards an international readership, these English language journals of China fared not so well in China either (Table 10). The analysis of Yu et al.  further supported claims made in the main text that journals published in China are caught in a dilemma: publishing in Chinese with a low international visibility versus publishing in English with a low local visibility.
Abstracts in non-English languages
The abstract of this paper has been translated into the following languages by the following translators (names in brackets):
Chinese – simplified characters (The author) [see Additional file 1]
Chinese – traditional characters (The author) [see Additional file 2]
French (Mr. Philip Harding-Esch) [see Additional file 3]
Spanish (Ms. Annick Bórquez) [see Additional file 4]
The author receives no funding for this paper.
Yu S-Z: Epidemiological methods: a view from China. The Development of Modern Epidemiology: Personal reports from those who were there. Edited by: Holland WW, Olsen J, Florey CdV Oxford: Oxford University Press; 2007.
Anderson GH: Peter Parker and the Introduction of Western Medicine in China. Mission Studies. 2006, 23: 203-238. 10.1163/157338306778985776
Sitthi-amorn C: The development of modern epidemioloogy in the East. The Development of Modern Epidemiology: Personal reports from those who were there. Edited by: Holland WW, Olsen J, Florey CdV Oxford: Oxford University Press; 2007.
Farley J: Bilharzia: a history of imperial tropical medicine Cambridge: Cambridge University Press; 1991.
Smith R: Chinese medical journals: getting in touch. Bmj. 1994, 309: 74.
Zhou P, Leydesdorff L: A comparison between the China Scientific and Technical Papers and Citations Database and the Science Citation Index in terms of journal hierarchies and interjournal citation relations. Journal of the American Society for Information Science and Technology. 2007, 58: 223-236. 10.1002/asi.20475. 10.1002/asi.20475
What Chinese means to all of us. http://podcast.timesonline.co.uk/serve.php/682/An-Introduction-From-Robert-Thomson.mp3
Learn Mandarin Chinese conversation (Times Online 11 February 2007).
Liu Q, Tian L-G, Xiao S-H, Qi Z, Steinmann P, Mak T, Utzinger J, Zhou X-N: Harnessing the wealth of Chinese scientific literature: schistosomiasis research and control in China. Emerging Themes in Epidemiology. 2008, 5: 19. 10.1186/1742-7622-5-19
National Library of Medicine: List of Journals Indexed for MEDLINE 2007. 2007.
Journals Recently Accepted by NLM for Inclusion in MEDLINE. http://www.nlm.nih.gov/bsd/lstrc/new_titles.html
Chinese Biomedical Literature Database (CBM). http://cbmwww.imicams.ac.cn
Chinese Medical Current Content (CMCC). http://www.cmcc.org.cn/
China National Knowledge Infrastructure (CNKI-CAJ). http://www.cnki.net/
China National Knowledge Infrastructure (CNKI) English portal. http://www.global.cnki.net/
VIP Information. http://www.cqvip.com/
Wan Fang database (Simplified Chinese portal). http://www.wanfangdata.com.cn/
Wan Fang database (English portal). http://www.wanfangdata.com/
Yahoo! Taiwan Academia Search. http://tw.search.yahoo.com/academia
Google Scholar. http://scholar.google.com
Google Scholar (Chinese interface). http://scholar.google.com/schhp?hl=zh-CN
Xia J, Wright J, Adams CE: Five large Chinese biomedical bibliographic databases: accessibility and coverage. Health Information and Libraries. 2008, 25: 55-61. 10.1111/j.1471-1842.2007.00734.x
Learn about pinyin search. http://web.archive.org/web/20071024144349/http:/scholar.google.com/intl/zh-CN/help/basics.html#pinyin
Google Scholar Advanced Scholar Search (Chinese interface). http://scholar.google.com/advanced_scholar_search?hl=zh-CN
Neuhaus C, Neuhaus E, Asher A, Wrede C: The depth and breadth of Google Scholar: An empirical study. Portal-Libraries and the Academy. 2006, 6: 127-141. 10.1353/pla.2006.0026. 10.1353/pla.2006.0026
International DOI Foundation announces launch of Chinese Registration Agency. http://www.doi.org/news/070319Wanfang.html
ECOJ: Browse by discipline. http://ecoj.wanfangdata.com/browse.aspx
English China Online Journals. A-Z List. http://ecoj.wanfangdata.com/List.aspx
Chinese Online Journals. http://www.wanfangdata.com/COJ/intr.asp
Lü YC: At the height of a hundred feet, move up one storey – a review from Guangxi Journal of Preventive Medicine to Applied Journal of Preventive Medicine [in Chinese]. Applied Journal of Preventive Medicine. 2006, 12 (4): I-III. http://www.ilib.cn/A-gxyfyx200604001.html
Scientific Electronic Library Online. http://www.SciELO.org/
Chinese Medical Journal. http://www.cmj.org/
List of Chinese journals in the category of Preventive Medicine and Hygienics (Wan Fang database, simplifed Chinese portal). http://c.wanfangdata.com.cn/S-root.R.R1.aspx
List of Chinese journals in the category of Preventive Medicine and Hygienics (iLib). http://scholar.ilib.cn/S-R.R1.html
Sun X-Z: An analysis of the impact of 41 medical university journals in China [in Chinese]. Chinese Journal of Scientific and Technical Periodical. 2006, 17: 1086-1089. http://www.ilib.cn/A-zgkjqkyj200606009.html
Comprehensive Lists of Titles of Chinese Core Journals 2004 (zhongwen hexin qikan yaomu zonglan 2004) [in Chinese]. http://hxqk.lib.pku.edu.cn/hxqk
Lists of Chinese databases (National Library of China). http://www.nlc.gov.cn/service/shujuku/cnlist.htm
Chinese Science Citation Database. http://www.thomsonreuters.com/products_services/scientific/Chinese_Science_Citation_DB
VIP Information Qikan Pingjia (Journal evaluation). http://www.cqvip.com/qikanpj/qkpj.asp
Chinese Medical Association: Carry forward the cause pioneered by our predecessors and forge ahead into the future to compose new movements of music – to our readers on the change of title of the series of Foreign Medical Sciences [in Chinese]. International Journal of Epidemiology and Infectious Disease. 2006, 33: 1. http://www.cma.org.cn/ArtShowContent.asp?ArticleID=568
Reproduction and Contraception (Website of both Journal of Reproduction and Contraception (English) and Reproduction and Contraception (Chinese)). http://www.randc.cn/
Chinese Preventive Medicine Association journal series. http://www.cpma.org.cn/05.asp?assort_id='05'
Jia X: Chinese University Journals: Status and Suggestions. Science Editor. 2006, 29: 123. http://www.councilscienceeditors.org/members/securedDocuments/v29n4p123.pdf
Journal of Molecular Cell Biology calls for contributions in English. http://www.cscb.org.cn/news.asp?id=477
Zhang YH, Wang S, Li J: The English-language academic journals of China: trends and developments. Learned Publishing. 2002, 15: 149-151. 10.1087/09531510252848926
Li L, Zhang FL: Understanding academic journals of China. Response to Yinian Gu. Scientometrics. 2003, 58: 697-700. 10.1023/B:SCIE.0000006890.14683.43
Puliselic L, Petrak J: Is it enough to change the language? A case study of Croatian biomedical journals. Learned Publishing. 2006, 19: 299-306. 10.1087/095315106778690733sss
Li ZX: How to establish a first-class international scientific journal in China?. World Journal of Gastroenterology. 2006, 12: 6905-6908.
Coura JR, Willcox Lde C: Impact factor, scientific production and quality of Brazilian medical journals. Mem Inst Oswaldo Cruz. 2003, 98: 293-297.
Aleixandre-Benavent R, Zurian JCV, Miguel-Dasit A, Arroyo AA, Gomez MC: Hypothetical influence of non-indexed Spanish medical journals on the impact factor of the Journal Citation Reports-indexed journals. Scientometrics. 2007, 70: 53-66. 10.1007/s11192-007-0104-x. 10.1007/s11192-007-0104-x
Miguel-Dasit A, Aleixandre R, Valderrama JC, Marti-Bonmati L, Sanfeliu P: Hypothetical influence of non-indexed Spanish journals on the impact factor of radiological journals. Eur J Radiol. 2005, 54: 321-326. 10.1016/j.ejrad.2004.07.017
Meneghini R, Mugnaini R, Packer AL: International versus national oriented Brazilian scientific journals. A scientometric analysis based on SciELO and JCR-ISI databases. Scientometrics. 2006, 69: 529-538. 10.1007/s11192-006-0168-z
Barros AJ: Scientific output in the collective health area: journal profile and evaluation by Capes [English translation from original Portuguese]. Rev Saude Publica. 2006, 40 Spec no.: 43-49.
Fang CH, Zhu XC: The open access movement in China. Interlending & Document Supply. 2006, 34: 186-193. 10.1108/02641610610714777
Chinese Preprint Service System. http://prep.istic.ac.cn/
Sciencepaper Online. http://www.paper.edu.cn
The Alliance of open access journals (OAJs). http://www.oajs.org/
Directory of Open Access Journals (DOAJ). http://www.doaj.org/
XE.com Conversion. http://www.xe.com/ucc/
BioMed Central. http://www.biomedcentral.com/
Public Library of Science. http://www.plos.org/
Ma A-F, Wang B-Y: Status Quo and Development of Chinese Open Access Sci-tech Publications [in Chinese]. Chinese Journal of Scientific and Technical Periodical. 2007, 18: 49-51. http://www.ilib.cn/A-Qcode~zgkjqkyj200701012.html
Mueller PS, Murali NS, Cha SS, Erwin PJ, Ghosh AK: The association between impact factors and language of general internal medicine journals. Swiss Medical Weekly. 2006, 136: 441-443.
Gregoire G, Derderian F, Lelorier J: Selecting The Language Of The Publications Included In A Metaanalysis – Is There A Tower-Of-Babel Bias. Journal Of Clinical Epidemiology. 1995, 48: 159-163. 10.1016/0895-4356(94)00098-B
Egger M, Zellweger-Zahner T, Schneider M, Junker C, Lengeler C, Antes G: Language bias in randomised controlled trials published in English and German. Lancet. 1997, 350: 326-329. 10.1016/S0140-6736(97)02419-7
Juni P, Holenstein F, Sterne J, Bartlett C, Egger M: Direction and impact of language bias in meta-analyses of controlled trials: empirical study. International Journal Of Epidemiology. 2002, 31: 115-123. 10.1093/ije/31.1.115
Moher D, Pham B, Klassen TP, Schulz KF, Berlin JA, Jadad AR, Liberati A: What contributions do languages other than English make on the results of meta-analyses?. Journal Of Clinical Epidemiology. 2000, 53: 964-972. 10.1016/S0895-4356(00)00188-8
Egger M, Juni P, Bartlett C, Holenstein F, Sterne J: How important are comprehensive literature searches and the assessment of trial quality in systematic reviews? Empirical study. Health Technol Assess. 2003, 7: 1-76.
Pham B, Klassen TP, Lawson ML, Moher D: Language of publication restrictions in systematic reviews gave different results depending on whether the intervention was conventional or complementary. Journal Of Clinical Epidemiology. 2005, 58: 769-776. 10.1016/j.jclinepi.2004.08.021
Moher D, Fortin P, Jadad AR, Juni P, Klassen T, LeLorier J, Liberati A, Linde K, Penna A: Completeness of reporting of trials published in languages other than English: Implications for conduct and reporting of systematic reviews. Lancet. 1996, 347: 363-366. 10.1016/S0140-6736(96)90538-3
Liu Z, Xiong T, Meads C: Clinical effectiveness of treatment with hyperbaric oxygen for neonatal hypoxic-ischaemic encephalopathy: systematic review of Chinese literature. Bmj. 2006, 333: 374. 10.1136/bmj.38776.731655.2F
Vickers A, Goyal N, Harland R, Rees R: Do Certain Countries Produce Only Positive Results? A Systematic Review of Controlled Trials. Controlled Clinical Trials. 1998, 19: 159-166. 10.1016/S0197-2456(97)00150-5
Tang J-L, Zhan S-Y, Ernst E: Review of randomised controlled trials of traditional Chinese medicine. BMJ. 1999, 319: 160-161.
Wang Q, Zhang B: Research design and statistical methods in Chinese medical journals. Jama. 1998, 280: 283-285. 10.1001/jama.280.3.283
Fung IC-H, Cairncross S: Effectiveness of handwashing in preventing SARS: a review. Trop Med Int Health. 2006, 11: 1749-1758. 10.1111/j.1365-3156.2006.01734.x
Royle P, Bain L, Waugh N: Systematic reviews of epidemiology in diabetes: finding the evidence. BMC Med Res Methodol. 2005, 5: 2. 10.1186/1471-2288-5-2
Clark OA, Castro AA: Searching the Literatura Latino Americana e do Caribe em Ciencias da Saude (LILACS) database improves systematic reviews. Int J Epidemiol. 2002, 31: 112-114. 10.1093/ije/31.1.112
Gastel B, Weng YQ: Medical journals in China. Ann Intern Med. 1990, 112: 70-72.
MEDLINE Factsheet. http://www.nlm.nih.gov/pubs/factsheets/nlm.html
China Online Journals – Introduction. http://www.wanfangdata.com/COJ/intr.asp
Bao G-H: Statistical analysis on Papers from Chinese Sci-tech Journals Cited by CAPLUS Database in 1932 ~ 2005 [in Chinese]. Chinese Journal of Scientific and Technical Periodical. 2006, 17: 392-395. http://www.ilib.cn/A-Qcode~zgkjqkyj200603012.html
Chinese Library Classification (Wikipedia – English entry). http://en.wikipedia.org/wiki/Chinese_Library_Classification
Bao G-H: Table of Statistical analysis on Papers from Chinese Sci-tech Journals Cited by CAPLUS Database in 1932 ~ 2005 [in Chinese]. Chinese Journal of Scientific and Technical Periodical. 2006, 17: 513-530. http://engine.cqvip.com/content/c/97176x/2006/017/003/sk54_c1_21993234.pdf
Bao G-H: Statistical analysis on Chinese Sci-tech Journals Cited by Scopus Database [in Chinese]. Chinese Journal of Scientific and Technical Periodical. 2006, 17: 1069-1077. http://www.ilib.cn/A-QCode~zgkjqkyj200606006.html
History of CMJ [in Chinese]. http://www.cmj.org/AboutUs/Information.asp?infoClass=HC
British Library. Integrated Catalogue. http://catalogue.bl.uk/F/?func=file&file_name=login-bl-list
Cheng TO: The Chinese Medical Journal vol 1, no. 1, January 1973. Jama. 1973, 224: 899-900. 10.1001/jama.224.6.899
Cheng TO: The new Chinese Medical Journal. Ann Intern Med. 1973, 78: 771-772.
Cheng TO: Editorial: Future development of Chinese medical journals. Ann Intern Med. 1973, 79 (6): 897-898.
Young TK: The Chinese Medical Journal. N Engl J Med. 1973, 289: 111.
Sidel VW: The Chinese medical journal. N Engl J Med. 1973, 289: 925.
Review and Prospect at the 100th anniversary of the Formosan Medical Association [Power point presentation in Chinese]. http://www.fma.org.tw/about05.html
Hong Kong Medical Journal. http://www.hkmj.org/
Hong Kong Medical Association. http://www.hkma.org/eindex.htm
Hong Kong Medical Association (Chinese Wikipedia). http://zh.wikipedia.org/wiki/%E9%A6%99%E6%B8%AF%E9%86%AB%E5%AD%B8%E6%9C%83
The Bulletin of the Hong Kong Chinese Medical Association (Online archive vol. 1 – 1969, vol. 21). http://sunzi1.lib.hku.hk/hkjo/issue.jsp?book=19
The Bulletin of the Hong Kong Medical Association (Online archive vol. 22 – 1984, vol. 36). http://sunzi1.lib.hku.hk/hkjo/issue.jsp?book=20
Journal of the Hong Kong Medical Association (Online archive vol. 37 – 1994, vol. 46). http://sunzi1.lib.hku.hk/hkjo/issue.jsp?book=21
Yu D-H, Shen Z-C, Shi J-Y, Deng X-Q, Yin C: Investigation on Status Quo of English Edition of Bio-medical Journals in China [in Chinese]. Chinese Journal of Scientific and Technical Periodical. 2007, 18: 227-233. http://www.ilib.cn/A-QCode~zgkjqkyj200702009.html
ICHF thanks Prof. Clive E. Adams for providing him with his manuscript on Chinese bibliographic databases  and alerting him to the existence of three of the five databases that are covered in his article. He is grateful to Mr. David Aanensen, Dr. Yan Che, Dr. Manoj Gambhir, Dr. James Lewis, Dr. Dabing Lu, Dr. Suzanne St. Rose, Dr. Clarence Tam, Dr. Yaobi Zhang and two reviewers for their scrutiny of the manuscript and their useful advice. ICHF thanks Mr. Philip Harding-Esch and Ms. Annick Bórquez for translating the abstract into French and Spanish respectively, Ms. Annick Bórquez and Ms. Gabriela Gomez for proof-reading the French and Spanish abstracts respectively, and Dr. Benny Lo for proof-reading the Chinese abstract. ICHF is supported by the HIV Monitoring Foundation, the Netherlands.
The author declares that they have no competing interests.
ICHF is a managing editor of the Emerging Themes in Epidemiology.
ICHF conceived the ideas of this study, conducted the analysis, and wrote the paper.