Sickle cell anaemia, recognized as a major public health problem by the World Health Organization (WHO) (WHO, 2006) is a genetic blood disorder characterized by abnormal red blood cells that assume a rigid, sickle shape (Chaudhary & Chaudhary, 2011). It is a genetically determined haematological disorder which was first observed in 1904 by Dr. J.B. Herrick in the blood of an anaemia West Indian medical student (Emechebe, Oyire, & Achigbu, 2017). It is a disease which decreases the flexibility of many red cells resulting in their destruction and blocking blood flow which may cause many complications. According to Grosse et al (2011) sickle cell anaemia is wide spread affecting many people in Africa and some other part of the world. According to Akinyanju (1989) Nigeria has the largest burden of sickle cell disorder in the world; Nigeria's large population has ensured that over 40 million Nigerians are healthy carriers of the S gene. This number of carriers far exceeds the total population of every other affected African country and indeed, of several of them put together. Consequently, about 150, 000 Nigerian children are born each year with sickle cell anaemia (HbSS), the prevailing type of sickle cell disorder (SCD) in this region (Akinyanju, 1989). Combatting the menace of sickle cell anaemia in the country requires not only financial support but also sickle cell anaemia research to discover the potential treatment and possible cure for the disease. In line with the National effort to kick against the sickle cell anaemia, this study was carried out to give the bibliometric analysis of sickle cell anaemia literature on Nigeria listed in PubMed in order to determine the productivity of medical researchers on sickle cell anaemia on Nigeria.
Bibliometrics is an approach used in measuring scientific publications and science in general(Meyer, 2009). Bibliometrics is the application of quantitative analysis and statistics to publications such as journal articles and their accompanying citation counts (Thomson Reuters, 2008). According to Oxford LibGuides (2018), Durieux & Gevenois (2010) and Kolle (2017), Bibliometrics is the statistical method engaged to analyse and measure the quantity and quality of books, articles, or other publications which canbe done using a set of statistical and mathematical indices called bibliometric indicators. There are three major categories of these indicators and these are the quantitative indicators that measure the research productivity of a researcher, performance indicators that evaluate the quality of publications and structural indicators that help to establish a link between publication, authors and research fields (Josh, 2014; Kolle, 2017; Durieux and Gevenois, 2010).Bibliometrics is used in research performance evaluation, especially in university and government laboratories, and also by policy makers, research directors and administrators, information specialists and librarians, and researchers themselves (Thomson Reuters, 2008). Therefore, bibliometric analysis is a discipline in which research work described in scientific literature is evaluated by measuring certain indicators (Carrizo-Sainero, 2000; Thom, 2008).
Innumerable studies have been carried out on citation analysis as well as bibliometric analysis of different medical literature. Vioque et al. (2009) conducted a bibliometric study of scientific literature on obesity research in PubMed (1988-2007)in order to give an overview of obesity research and to explore to what extent scientific production parallels the so-called obesity epidemic. Akinola (2016) conducted citation analysis of paediatrics literature on Nigeria listed in Medline during 2002-2012, to understand the information need, use, sources and trends in the citation window. Ugolini et al. (2013) conducted bibliometric analysis of literature in cerebrovascular and cardiovascular diseases rehabilitationin order to explore temporal trends, geographic distribution, and socioeconomic determinants of scientific production in the field of cerebrovascular and cardiovascular disease (CCD) rehabilitation. Huang et al. (2015) conducted a retrospective bibliometric analysis of articles about traditional Chinese medicine (TCM) research in PubMed in order to learn about the development and perspective of TCM. Olayiwola (2015) conducted Bibliometric analysis of Ebola research in Africa, studying the characteristics of Ebola literature on Africa and utilized some evaluative bibliometric design to figure out citations of the publication. Glynn et al (2010) conducted bibliometric analysis on representation of cancer in the medical literature, which was used to measure the proportion, quality and relevance of articles for the most common cancer types. Yang, Pan and Chen (2009), conducted citation analysis of five journals in Andrology, which was used to find out the features in literature demand by researchers in the field of Andrology.
Despite the remarkable bibliometric research activities in medical sciences, no known study has been carried out on sickle cell anaemia literature listed in PubMed, particularlyon Nigeria.Therefore, the present study aims at carrying out bibliometric analysis of sickle cell anaemia literature on Nigeria listed in PubMed between 2006 and 2016 in order to investigate the research productivity output of medical researchers in Nigeria on sickle cell anaemia in the published articles included in the electronic database, PubMed.
Bibliometric methods have been applied to several studies to determine research productivity of journals, institutions and scientists as well as to discover productivity trends of articles.
As it was said by Levi et al (2009) and Sanni (2011), one of the most tangible production units of science in any country is research publications, and indeed the number of publications and the amount of citations these papers received. Adeniyi (2012) applied a series of bibliometric indicators to study biomedical literature in selected West African Countries between 2002 and 2011; it was revealed that Nigeria was the most productive country with 51.6% articles which made her the country with the highest number of publications among the selected West Africa countries. In a study which explored the literature of diabetes in Nigeria, Harande (2011) reported that the production of diabetes literature in Nigeria in the year 1986-2009 revealed that from the year 1986 the growth of literature became exponential. Uthman (2008) had similar observation that Nigeria has achieved a significant increase in the number of publications while Harade(2011) said that the possible explanation for the growth of the literature clearly showed that medical research is gaining attention and interest from Nigeria scientists, medical practitioners, researchers and scholars, which maybe as a result of the general population increase, as well as prevalence of specific diseases
The number of citations an article receives is an important indicator of impact and contribution to clinical world (Shuaib et al, 2015). In a study conducted by Shuaib et al (2015), it was revealed that there was a paucity of literature concerning top article citations in cardiology. It was also revealed that the most highly cited articles were published in variety of journals in which half of the articles were published in Circulation and European Heart Journal. Contrary to this, the study of bibliometric analysis of citation classics of acute appendicitis revealed that Radiology, Annals of Surgery and British Journal of Surgery were the top three journals with 15, 13, 11 respectively (Varzgalis, 2017). Shuaib et al (2015) also found out that general medical journals such as the lancet and the New England Journal of Medicine contributed only 5 articles to the list despite their extremely high impact factor.
Huang et al. (2015) conducted a retrospective bibliometric analysis of articles about traditional Chinese medicine (TCM) research in PubMed in order to learn about the development and perspective of TCM. It was observed that the articles originated from 102 countries and territories. China had the highest number of publications with 20,121 articles, followed by United States with 2207 articles and 57.74 % of the articles were published in English. It was also established that the publication activity of TCM literature increased rapidly in the past 20 years, indicating enhanced attention attracted to TCM and more research input.
Vioque et al (2009) analysed publications on obesity research in PubMed from 1988 to 2007. The result showed that there was an exponential increase in the number of publications on obesity. The references were published in 3613 different journals, with 20 journals...