The Dynamic Interest in Topics within the Biomedical Scientific Community

The increase in the size of the scientific community created an explosion in scientific production. We have analyzed the dynamics of biomedical scientific output during 1957–2007 by applying a bibliometric analysis of the PubMed database using different keywords representing specific biomedical topics. With the assumption that increased scientific interest will result in increased scientific output, we compared the output of specific topics to that of all scientific output. This analysis resulted in three broad categories of topics; those that follow the general trend of all scientific output, those that show highly variable output, and attractive topics which are new and grow explosively. The analysis of the citation impact of the scientific output resulted in a typical longtail distribution: the majority of journals and articles are of very low impact. This distribution has remained unchanged since 1957, although the interests of scientists must have shifted in this period. We therefore analyzed the distribution of articles in top journals and lower impact journals over time for the attractive topics. Novelty is rewarded by publication in top journals. Over time more articles are published in low impact journals progressively creating the longtail distribution, signifying acceptance of the topic by the community. There can be a gap of years between novelty and acceptance. Within topics temporary novelty is created with new subtopics. In conclusion, the longtail distribution is the foundation of the scientific output of the scientific community and can be used to examine different aspects of science practice.     

Croatian bibliometric analysis, 2000-2007

To develop search filters and retrieve information estimating the Croatian scientific output (SO) focusing on Public Health (PH) and Preventive Medicine (PM) in MEDLINE. A PubMed search of the MEDLINE database was performed to retrieve articles added to this database between 2000 and 2007. Search filters inspired by previous strategies were applied involving 'geographical', 'place of publication', 'subject' and 'language of publication' aspects. An evaluation of the geographical filter performance was done and sensitivity and specificity were calculated. There were obtained publications in several languages, originated in Croatia, published in Croatia and/or abroad. The Croatian SO in the field of PH-PM was obtained for the same period of time by combining search filters. The evaluation of the filter performance showed sensitivity 95.56% and specificity 100%. The filters constructed permitted the retrieval of the Croatian eight years research output. Increased tendency was observed in the global SO evolution and in the PH-PM area as well. The main languages of publication were English and Croatian. This study is a contribution to research in the field of scientific documentation and further analysis is recommended in constructing and developing search filters to retrieve and focus on specific information.     

Epidemiological patterns of tuberculosis in Croatia in the period 1996-2005

The last comprehensive publication on tuberculosis in Croatia and the earliest impact of war, besides the yearly routine reports, was done in 1996 in Croatian. We were, therefore, interested to explore incidence trends and to highlight the early post-war tuberculosis epidemiological patterns in the next ten years period (1996-2005). A retrospective analysis of epidemiological data on all registered tuberculosis cases in Croatia searching the databases of 21 Croatian Public Health Institutes and the National Tuberculosis Registry was made. During the study period, the total tuberculosis incidence rates in Croatia dropped from 45 to 25.8/100 000 inhabitants. The average highest age-specific rates were recorded in the age group > or = 65 years being in decrease in all age groups. Paediatric cases (0-14 years) represented 4.5% of all cases. Tuberculosis cases among males were recorded in 64% cases, and 83.6% were indigenous population. Tuberculosis was bacteriologically confirmed in 67.7% cases. A low proportion of drug resistance (3.3%) was recorded. During 1985-2005, 56 tuberculosis cases among 242 AIDS cases were reported. Tuberculosis mortality showed a decreasing trend (p < 0.001). However, tuberculosis has still had the highest mortality rates among infectious diseases in Croatia. Despite the War chain of events and tuberculosis programmatic changes, tuberculosis incidence rates in Croatia have been decreasing but they are still far away from national target, incidence rate of 10/100 000 declared in 1998 and much higher than in European Union and Western Europe. Tuberculosis among children, resistance to tuberculosis drugs and HIV prevalence, significant problems in many European countries, have not caused problems in tuberculosis control in Croatia. This favourable epidemiological situation must be kept and improved through strengthened tuberculosis control measures.     

Effects of war aggression in Croatia on some forms and manifestations of breast cancer

The aim of this study was to determine the differences in epidemiological and clinical manifestations of breast cancer in time of war in Croatia and in peacetime before and after the war, in the defined population of Pozesko-Slavonska County. The methods used in this study were the evaluation of relative predictive value of variables by means of chi 2-test and the analysis of variance, while the survival studies were tested by Long Rank test according to Kaplan-Meier analysis of survival. This work encompasses 660 patients who had breast cancer. The differences between three time periods were evaluated: the war period (1991-1995), and two control periods: before the war (1981-1990) and after the war (1996-2000). The patients were grouped by age, localization of tumor and survival. During the war period the patients were, on the average, 4.2 years younger than those who acquired the disease in control periods, and the mean age of patients was between 50 and 59 years (36.5% of patients). Although the difference in tumor distribution by sides (left or right breast) and quadrants was statistically significant (war period vs. control periods; p < 0.001), there was no statistically significant difference in the survival of patients according to the results of Kaplan-Meier analysis of localization of tumor (p > 0.05). The length of survival in terms of age of patients in time of surgical procedure was significantly different (p < 0.001). This study confirms the effects of war on some epidemiological and clinical manifestation of breast cancer in the defined population of Pozesko-Slavonska County.     

基于文献计量的植物雌雄异株研究进展

雌雄异株植物是研究植物性别的理想材料,同时作为生态系统的重要组成部分,对生物多样性的维持与保护起着重要作用。该文从文献计量学角度综述了雌雄异株植物相关研究的进展。通过检索Web of Science(WOS)平台的SCI-E数据库和CNKI数据库的有关雌雄异株研究的文献数据,从文献年代分布、期刊分布、研究国家与机构、核心作者和高引论文等方面进行了分析,并借助CitespaceⅢ信息可视化软件绘制雌雄异株植物研究的科学知识图谱,总结了雌雄异株研究的热点和前沿。结果表明:WOS数据库中,雌雄异株植物研究呈现快速上升趋势,就发文总量来看,发文前五的国家为美国、日本、加拿大、英格兰和中国。其中,美国发文量占比为31.03%;中国科学院为发文量最多的机构,发文占比3.36%,其次为牛津大学(2.613%),多伦多大学位列第三(2.427%);中国,巴西和印度三国,西班牙马萨里克大学和北京林业大学两个研究机构近5年来在该领域发文增量较快。论文主要集中在植物科学、环境科学与生态学和遗传学等学科。载文量前十位的期刊累计载文占比高达24.13%,发文量最多的期刊为American Journal of Botany,占总发文量的6.07%,其次为Evolution(2.80%),Annals of Botany(2.52%)排名第三。发文最多的作者为捷克科学院的VYSKOT B,发文占总数的2.57%,高引论文大多出自美国学者之手。从CNKI数据库看,西华师范大学、北京林业大学和河南师范大学发文数量位列前三,发文量最高的期刊为《生命世界》,占总发文量的3.00%。综合Web of Science和CNKI两大数据库的文献来看,青杨和番木瓜作为研究雌雄异株植物的模式植物,近年发文较多。当前的研究热点主要集中在雌雄性别决定,繁殖代价,雌雄个体对环境因子的响应差异等方面。     

Contribution of case reports to brain metastases research: systematic review and analysis of pattern of citation

Research activity related to different aspects of prevention, prediction, diagnosis and treatment of brain metastases has increased during recent years. One of the major databases (Scopus) contains 942 scientific articles that were published during the 5-year time period 2006–2010. Of these, 195 (21%) reported on single patient cases and 12 (1%) were reports of 2 cases. Little is known about their influence on advancement of the field or scientific merits. Do brain metastases case reports attract attention and provide stimuli for further research or do they go largely unrecognized? Different measures of impact, visibility and quality of published research are available, each with its own pros and cons. For the present evaluation, article citation rate was chosen. The median number of citations overall and stratified by year of publication was 0, except for the year 2006 when it was 2. As compared to other articles, case reports remained more often without citation (p<0.05 except for 2006 data). All case reports with 10 or more citations (n = 6) reported on newly introduced anticancer drugs, which commonly are prescribed to treat extracranial metastases, and the responses observed in single patients with brain metastases. Average annual numbers of citations were also calculated. The articles with most citations per year were the same six case reports mentioned above (the only ones that obtained more than 2.0 citations per year). Citations appeared to gradually increase during the first two years after publication but remained on a generally low or modest level. It cannot be excluded that case reports without citation provide interesting information to some clinicians or researchers. Apparently, case reports describing unexpected therapeutic success gain more attention, at least in terms of citation, than others.     

Why Most Biomedical Findings Echoed by Newspapers Turn Out to be False: The Case of Attention Deficit Hyperactivity Disorder

Context

Because positive biomedical observations are more often published than those reporting no effect, initial observations are often refuted or attenuated by subsequent studies.

Objective

To determine whether newspapers preferentially report on initial findings and whether they also report on subsequent studies.

Methods

We focused on attention deficit hyperactivity disorder (ADHD). Using Factiva and PubMed databases, we identified 47 scientific publications on ADHD published in the 1990s and soon echoed by 347 newspapers articles. We selected the ten most echoed publications and collected all their relevant subsequent studies until 2011. We checked whether findings reported in each “top 10” publication were consistent with previous and subsequent observations. We also compared the newspaper coverage of the “top 10” publications to that of their related scientific studies.

Results

Seven of the “top 10” publications were initial studies and the conclusions in six of them were either refuted or strongly attenuated subsequently. The seventh was not confirmed or refuted, but its main conclusion appears unlikely. Among the three “top 10” that were not initial studies, two were confirmed subsequently and the third was attenuated. The newspaper coverage of the “top 10” publications (223 articles) was much larger than that of the 67 related studies (57 articles). Moreover, only one of the latter newspaper articles reported that the corresponding “top 10” finding had been attenuated. The average impact factor of the scientific journals publishing studies echoed by newspapers (17.1 n = 56) was higher (p<0.0001) than that corresponding to related publications that were not echoed (6.4 n = 56).

Conclusion

Because newspapers preferentially echo initial ADHD findings appearing in prominent journals, they report on uncertain findings that are often refuted or attenuated by subsequent studies. If this media reporting bias generalizes to health sciences, it represents a major cause of distortion in health science communication.     

Biomedical research in Revista de Biologia Tropical

The contributions published in Revista de Biología Tropical in the area of Biomedical Sciences are reviewed in terms of number of contributions and scope of research subjects. Biomedical Sciences, particularly Parasitology and Microbiology, constituted the predominant subject in the Revista during the first decade, reflecting the intense research environment at the School of Microbiology of the University of Costa Rica and at Hospital San Juan de Dios. The relative weight of Biomedicine in the following decades diminished, due to the outstanding increment in publications in Biological Sciences; however, the absolute number of contributions in Biomedical Sciences remained constant throughout the last decades, with around 80 contributions per decade. In spite of the predominance of Parasitology as the main biomedical subject, the last decades have witnessed the emergence of new areas of interest in the Revista, such as Pharmacology of natural products, Toxinology, especially related to snake venoms, and Human Genetics. This retrospective analysis evidences that Biomedical Sciences, particularly those related to Tropical Medicine, were a fundamental component during the first years of Revista de Biología Tropical, and have maintained a significant presence in the scientific output of this journal, the most relevant scientific publication in biological sciences in Central America.     

Why Has the Number of Scientific Retractions Increased?

Background

The number of retracted scientific publications has risen sharply, but it is unclear whether this reflects an increase in publication of flawed articles or an increase in the rate at which flawed articles are withdrawn.

Methods and Findings

We examined the interval between publication and retraction for 2,047 retracted articles indexed in PubMed. Time-to-retraction (from publication of article to publication of retraction) averaged 32.91 months. Among 714 retracted articles published in or before 2002, retraction required 49.82 months; among 1,333 retracted articles published after 2002, retraction required 23.82 months (p<0.0001). This suggests that journals are retracting papers more quickly than in the past, although recent articles requiring retraction may not have been recognized yet. To test the hypothesis that time-to-retraction is shorter for articles that receive careful scrutiny, time-to-retraction was correlated with journal impact factor (IF). Time-to-retraction was significantly shorter for high-IF journals, but only ∼1% of the variance in time-to-retraction was explained by increased scrutiny. The first article retracted for plagiarism was published in 1979 and the first for duplicate publication in 1990, showing that articles are now retracted for reasons not cited in the past. The proportional impact of authors with multiple retractions was greater in 1972–1992 than in the current era (p<0.001). From 1972–1992, 46.0% of retracted papers were written by authors with a single retraction; from 1993 to 2012, 63.1% of retracted papers were written by single-retraction authors (p<0.001).

Conclusions

The increase in retracted articles appears to reflect changes in the behavior of both authors and institutions. Lower barriers to publication of flawed articles are seen in the increase in number and proportion of retractions by authors with a single retraction. Lower barriers to retraction are apparent in an increase in retraction for “new” offenses such as plagiarism and a decrease in the time-to-retraction of flawed work.     

The secular trend in the incidence of hemorrhagic stroke in the region of Osijek,Eastern Croatia in the period 1988-2000--a hospital based study

The purpose of the study was to establish the possible environmental influences in the observed peculiar rising and falling oscillations in the numbers of hemorrhagic stroke (HS) in Eastern Croatia (region of Osijek) during the last thirteen-years' period (1988-2000). In this period 1,222 HS were registered and treated. A constant increase in the incidence of HS was observed, from 60 (in 1988) to 139 (in 1998), with an average annual proportion of 16.5% of all stroke cases. A sharp increase in proportion of HS in total stroke incidence was recorded during the war in Croatia (1991-1995), with a peak incidence of 27.4% in 1993. Typical hypertensive intracerebral hemorrhage (ICH) was the most common (57.1%), atypical ICH occurred in 26.4%, subarachnoid hemorrhage (SAH) in 16.5%. Analysis of the annual number of hypertensive-ICH and SAH disclosed peculiar rising and falling oscillations. These variations were in correlation with heavy living conditions. During the war-period the SAH incidence sharply rose. Immediately after the war it suddenly decreased. The authors named this phenomenon a "pool depletion", supposing the relatively stable proportion of the bearers of aneurysms in population. The observed variations seem to be the consequence of the war stress and other negative psychosocial and economic factors in post-war period, which increases the risk for SAH and typical hypertensive-ICH through complex pathophysiological mechanisms.     

Publication of Original Research in Urologic Journals – A Neglected Orphan?

The pathophysiologic mechanisms behind urologic disease are increasingly being elucidated. The object of this investigation was to evaluate the publication policies of urologic journals during a period of progressively better understanding and management of urologic disease. Based on the ISI Web of Knowledge Journal Citation Reports and the PubMed database, the number and percentage of original experimental, original clinical, review or commentarial articles published between 2002–2010 in six leading urologic journals were analyzed. “British Journal of Urology International”, “European Urology”, “Urologic Oncology-Seminars and Original Investigations” (“Urologic Oncology”), “Urology”, “The Journal of Urology”, and “World Journal of Urology” were chosen, because these journals publish articles in all four categories. The publication policies of the six journals were very heterogeneous during the time period from 2002 to 2010. The percentage of original experimental and original clinical articles, related to all categories, remained the same in “British Journal of Urology International”, “Urologic Oncology”, “Urology” and “The Journal of Urology”. The percentage of experimental reports in “World Journal of Urology” between 2002–2010 significantly increased from 10 to 20%. A distinct elevation in the percentage of commentarial articles accompanied by a reduction of clinical articles became evident in “European Urology” which significantly correlated with a large increase in the journal’s impact factor. No clearly superior policy could be identified with regard to a general increase in the impact factors from all the journals. The publication policy of urologic journals does not expressly reflect the increase in scientific knowledge, which has occurred over the period 2002–2010. One way of increasing the exposure of urologists to research and expand the interface between experimental and clinical research, would be to enlarge the percentage of experimental articles published. There is no indication that such policy would be detrimental to a journal’s impact factor.     

Growth and development of biofeedback: a bibliographic update

Computerized literature searching techniques were used to examine publication patterns in the worldwide biofeedback literature. Searches were completed in the United States and in Japan for the years 1985 through 1987. The results were used to update the results of an earlier study that covered the years from 1964 through 1984. Publication growth curves were generated for several media, including scientific journal articles, books, doctoral dissertations, and popular magazine articles. Although publication of information about biofeedback remains active worldwide, there has been a declining trend in effect for the past several years. The American database grossly underestimated the number of Japanese biofeedback articles, and it is likely that the literatures of other countries outside of North America were similarly underestimated. Possible explanations for the various trends noted are discussed.     

Effects of war aggression in Croatia on histopathological manifestations of breast cancer in defined population of one county

The aim of the present study was to determine the differences in epidemiological and clinical manifestations of breast cancer during the war in Croatia and in peacetime. 660 consecutive patients were recorded (656 female and 4 male patients) from Pozesko-Slavonska County. The changes in histopathological features were recorded in war period (1991-1995, 156 patients) and through two control periods, before the war (1981-1990, 282 patients) and after the war (1995-2000, first five months, 223 patients). The relative predictive value was calculated using chi 2-test. The survival was calculated according to Kaplan-Meier analysis of survival. The histopathological analysis showed an equal distribution of noninvasive cancer (in situ cancer) across periods. In the war period, the level of the most common invasive cancer, ductal breast cancer, was lower (57.7%), compared to control periods (71.2%:63.7%:68.2%). Opposite to that, invasive lobular cancer was more common in the war period (3.2%), compared to control periods (0.7%-1.3%). Furthermore, mixed cancer was also increased in the war period (7.1%) compared to control periods (0.7%-2.2%), as was medullar cancer (10.9% vs. 5.5%-5.9%). The study showed statistically significant differences in the survival of patients with different histopathological diagnoses (Log Rank = 47.49, df = 7, p < 0.0001), while the histological grade of tumor, as a predictive factor was not proved to be statistically significant (p > 0.05). This study confirmed the influence of war of war on histopathological incidence of some forms of breast cancer.     

Growth and development of biofeedback: a bibliographic analysis

A computerized search was performed, and a bibliography was prepared on the subject of biofeedback covering the years from 1964 to 1985. Growth curves were produced for various publication media. The search produced references to 2,431 journal articles, 102 books, 79 popular magazine articles, and 551 doctoral dissertations. The journal articles were sorted according to the country of publication, language, and primary topic of the journal. Citations were found from 35 countries, written in 18 languages. All the media studied showed a period of rapid growth during the early to middle 1970s, but there was a tendency for leveling off or slight decline during the early 1980s. Publication of articles in medical journals has shown the greatest growth, and more articles are published yearly in medical journals than in journals of any other discipline or all specialty journals combined. Publication in psychological journals has shown a decline since 1977. Dental, nursing, and educational journals have shown a low rate of publication of biofeedback articles, indicating little or no growth.     

El duro peregrinaje de las revistas biomédicas españolas hacia la excelencia: ¿quién nos ayuda? Calidad,impacto y méritos de la investigación

Biomedical journals must adhere to strict standards of editorial quality. In a globalized academic scenario, biomedical journals must compete firstly to publish the most relevant original research and secondly to obtain the broadest possible visibility and the widest dissemination of their scientific contents. The cornerstone of the scientific process is still the peer-review system but additional quality criteria should be met. Recently access to medical information has been revolutionized by electronic editions.Bibliometric databases such as MEDLINE, the ISI Web of Science and Scopus offer comprehensive online information on medical literature. Classically, the prestige of biomedical journals has been measured by their impact factor but, recently, other indicators such as SCImago SJR or the Eigenfactor are emerging as alternative indices of a journal's quality. Assessing the scholarly impact of research and the merits of individual scientists remains a major challenge. Allocation of authorship credit also remains controversial.Furthermore, in our Kafkaesque world, we prefer to count rather than read the articles we judge. Quantitative publication metrics (research output) and citations analyses (scientific influence) are key determinants of the scientific success of individual investigators. However, academia is embracing new objective indicators (such as the “h” index) to evaluate scholarly merit. The present review discusses some editorial issues affecting biomedical journals, currently available bibliometric databases, bibliometric indices of journal quality and, finally, indicators of research performance and scientific success.     

Growth and development of biofeedback: A bibliographic analysis

A computerized search was performed, and a bibliography was prepared on the subject of biofeedback covering the years from 1964 to 1985. Growth curves were produced for various publication media. The search produced references to 2,431 journal articles, 102 books, 79 popular magazine articles, and 551 doctoral dissertations. The journal articles were sorted according to the country of publication, language, and primary topic of the journal. Citations were found from 35 countries, written in 18 languages. All the media studied showed a period of rapid growth during the early to middle 1970s, but there was a tendency for leveling off or slight decline during the early 1980s. Publication of articles in medical journals has shown the greatest growth, and more articles are published yearly in medical journals than in journals of any other discipline or all specialty journals combined. Publication in psychological journals has shown a decline since 1977. Dental, nursing, and educational journals have shown a low rate of publication of biofeedback articles, indicating little or no growth.We thank Ken Hartman for his assistance in performing this study.     

Six authors in search of a citation: villains or victims of the Vancouver convention?

OBJECTIVES--To analyse trends in the number of authors per article over the past 10 years. DESIGN--Analysis of articles from random volumes of eight biomedical journals. SUBJECTS--Cell, Nature, Proceedings of the National Academy of Sciences USA (PNAS), Journal of Clinical Investigation (JCI), Biochemical and Biophysical Research Communications (BBRC), Journal of Clinical Oncology (JCO), New England Journal of Medicine (NEJM), Lancet. MAIN OUTCOME MEASURES--Median and modal numbers of authors. RESULTS--All journals except Cell and Nature showed a trend towards increasing authorship numbers over the study period. The trend was most noticeable in journals such as JCO which feature clinical research. General medical journals (Lancet, NEJM) with a median of six to seven authors per article published far fewer seven author than six author studies, which suggests that author number may be influenced by the Vancouver convention which precludes citation of more than six authors. CONCLUSIONS--The phenomenon of expanding authorship in biomedical journal articles is not explained by the hypothesis that newer research technologies have necessitated more extensive collaboration. Rather, the data suggest that conferral of authorship may sometimes have a volitional component which contributes to rising author numbers. It is proposed that replacement of the Vancouver convention with a "first author, last author" citation system may help stem this rise in author numbers.     

Q fever in Croatia: war-induced changes in epidemiological characteristics

The article describes the epidemiological characteristics of Q fever in Croatia, during the period before and after the Homeland War. In the ten years prior to the Homeland War (1983-1992) 1053 cases of Q fever were recorded, 16.2% (171) of which on islands and in coastal areas. In the period after the Homeland War (1995-2008), a total of 654 cases was recorded, 59.9% (392) of which on islands and in coastal areas. In addition to reduced incidence, geographic distribution of the disease also changed. Before the war, the highest morbidity rate was recorded in the Sisak-Moslavina County. After the war, the Split-Dalmatia County recorded the highest morbidity rate because in the post-war period sheep from Bosnia and Herzegovina went to this county for winter grazing. The disease might be relevant to the Croatian Army and other armed forces that stay in Croatia as part of NATO forces.     

The changing pattern of cardiovascular risk factors: the CroHort study

Croatia has a long tradition of non-communicable disease prevention, but also obstacles to the implementation of preventive programs related to the general attenuation of public health and primary health care sector. The aim of this study was to determine trends in behavioral and biomedical risk factors and evaluate primary non-communicable disease and cardiovascular prevention. Physical inactivity was a leading risk factor with increasing trend and prevalence of 33.9% and 38.9% in men and women in 2008. In 2008, obesity was present in 26.1% and 34.1%, and hypertension in 65.8% and 59.7% of men and women. During the follow-up only smoking and alcohol consumption in men decreased significantly, while alcohol consumption and obesity in women, and hypertension in both sexes significantly increased. In the present situation, with the existing trends and environment it will not be possible to stop negative trends. Revitalization of public health activities and primary health care is essential.