Socioeconomic Determinants, Regional Differences, and Quality of Nephrology Research in Africa

The prevalence of chronic kidney disease (CKD) continues to rise globally.1Liyanage T. Ninomiya T. Jha V. et al.Worldwide access to treatment for end-stage kidney disease: a systematic review.Lancet. 2015; 385: 1975-1982Abstract Full Text Full Text PDF PubMed Scopus (1116) Google Scholar,2Bello A.K. Levin A. Tonelli M. et al.Assessment of global kidney health care status.JAMA. 2017; 317: 1864-1881Crossref PubMed Scopus (218) Google Scholar However, this has been found to be disproportionately higher in several low-income and low-to-middle−income countries.1Liyanage T. Ninomiya T. Jha V. et al.Worldwide access to treatment for end-stage kidney disease: a systematic review.Lancet. 2015; 385: 1975-1982Abstract Full Text Full Text PDF PubMed Scopus (1116) Google Scholar,3Xie Y. Bowe B. Mokdad A.H. et al.Analysis of the Global Burden of Disease study highlights the global, regional, and national trends of chronic kidney disease epidemiology from 1990 to 2016.Kidney Int. 2018; 94: 567-581Abstract Full Text Full Text PDF PubMed Scopus (365) Google Scholar Providing adequate kidney care for CKD patients depends on numerous factors, including an understanding of disease epidemiology, disease outcomes, response to treatment, and prognostic factors, as well as the availability of various items necessary to provide care for such patients. These elements are established and frequently updated through various forms of rigorous research. The International Society of Nephrology (ISN) first Global Kidney Health Atlas (GKHA) reported that Africa was consistently lagging behind other world regions in the capacity to participate in clinical trials or observational studies in nephrology.4Okpechi I.G. Alrukhaimi M. Ashuntantang G.E. et al.Global capacity for clinical research in nephrology: a survey by the International Society of Nephrology.Kidney Int Suppl. 2018; 8: 82-89Abstract Full Text Full Text PDF Scopus (8) Google Scholar Other studies have also shown that Africa has the lowest contributions to biomedical publications when all world regions are considered.5Soteriades E.S. Rosmarakis E.S. Paraschakis K. Falagas M.E. Research contribution of different world regions in the top 50 biomedical journals (1995–2002).FASEB J. 2006; 20: 29-34Crossref PubMed Scopus (49) Google Scholar Several factors are linked to biomedical research outputs, and include the available national funding structures for research and development, number of higher institutions of learning, availability of research infrastructure, training, mentorship and peer networks for research.6Horton R. North and south: bridging the information gap.Lancet. 2000; 355: 2231-2236Abstract Full Text Full Text PDF PubMed Scopus (159) Google Scholar,7Meo S.A. Al Masri A.A. Usmani A.M. et al.Impact of GDP, spending on R&D, number of universities and scientific journals on research publications among Asian countries.PLoS One. 2013; 8e66449Crossref PubMed Scopus (93) Google Scholar The aim of this descriptive study is to provide a brief report on the quantity and quality of published research in nephrology from Africa (by country and region) over a period spanning 5 decades. We identified 17,256 records from bibliographic searches; after removing duplicates (771), we screened 16,151 titles and abstracts and identified eligible 1326 articles (Figure 1, Supplementary Table S1). The number of publications increased over the study period and peaked in 2015 (Figure 2a). Included articles were from 34 African countries, and the top 5 publishing countries were Nigeria (31.1%), Egypt (13.3%), South Africa (11.9%), Morocco (5.4%), and Tunisia (4.8%) (Table 1, Figure 2b). When considered based on the number of physicians per 1000 population, Nigeria, South Africa, Egypt, Tunisia, and Morocco were still the top 5 countries. However, when based on number of articles per 10 million population, the 5 countries were Seychelles (105.6), Tunisia (54.6), South Africa (27.9), Senegal (25.2), and Nigeria (21.6). With reference to the first author (and study setting), the proportion of articles published by region were as follows: West Africa, 39.1%; North Africa, 28.7%; Southern Africa, 12.1%; East Africa, 7.7%; and Central Africa, 3.6%. The others were from non-African first authors (Figure 3a).Figure 2(a) Trends in number of articles published in Africa. (b) Number of articles published per country in Africa.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Table 1Sociodemographic details, quality and quantity of articles published from included countries in AfricaCountryPopulationGDPHDILiteracy rateNo. of physicians (pmp)No. of articles (%)No. of articles in IF journals (%)No. of RCTs (%)Nigeria189,374,68562670.52951.628.9412 (31.1)107 (21.6)0 (0.0)Egypt97,553,15111,3810.69275.254.5176 (13.3)73 (14.7)2 (40.0)South Africa56,067,47713,4720.66594.176.2158 (11.9)103 (20.8)0 (0.0)Morocco35,739,58078380.64769.451.071 (5.4)18 (3.6)0 (0.0)Tunisia11,532,12711,5990.72579.0134.063 (4.8)27 (5.5)1 (20.0)Sudan40,533,33058950.49053.522.057 (4.3)8 (1.6)0 (0.0)Senegal15,850,56727420.49643.37.240 (3.0)5 (1.0)0 (0.0)Kenya49,699,86231560.55578.714.035 (2.6)4 (0.8)0 (0.0)Cameroon24,053,72732860.51871.319.025 (1.9)15 (3.0)0 (0.0)Ghana28,833,62942940.57971.515.021 (1.6)9 (1.8)0 (0.0)Democratic Republic of Congo81,339,98857190.43579.311.019 (1.4)18 (3.6)0 (0.0)Ivory Coast24,294,75037200.47443.912.016 (1.2)8 (1.6)0 (0.0)Uganda42,862,95826950.49370.28.015 (1.1)12 (2.4)0 (0.0)Ethiopia104,957,43817350.44839.03.013 (1.0)3 (0.6)0 (0.0)Zimbabwe16,529,90420060.51688.716.012 (0.9)2 (0.4)0 (0.0)Tanzania57,310,01927870.53177.92.010 (0.8)4 (0.8)0 (0.0)Zambia17,094,13039220.57983.012.010 (0.8)3 (0.6)0 (0.0)Togo7,797,69414910.48763.84.09 (0.7)1 (0.2)0 (0.0)Libya6,374,61698000.71660.2129.07 (0.5)2 (0.4)0 (0.0)Algeria41,318,14213,0530.70369.895.26 (0.5)2 (0.4)0 (0.0)Burkina Faso19,193,38217200.40234.66.06 (0.5)3 (0.6)0 (0.0)Benin11,175,69222190.48532.94.05 (0.4)0 (0.0)0 (0.0)Mali18,541,98021170.44233.18.04 (0.3)0 (0.0)0 (0.0)Republic of Congo81,339,98857190.59279.320.04 (0.3)3 (0.6)0 (0.0)Guinea12,717,17613110.42432.012.03 (0.2)0 (0.0)0 (0.0)Botswana2,291,66116,7350.69881.240.02 (0.2)2 (0.4)0 (0.0)Madagascar25,570,89515060.51271.629.02 (0.2)0 (0.0)0 (0.0)Malawi18,622,10411690.47662.12.02 (0.2)1 (0.2)0 (0.0)Gambia2,100,56816890.45241.911.01 (0.1)1 (0.2)0 (0.0)Lesotho2,203,82130290.49776.65.01 (0.1)1 (0.2)0 (0.0)Niger21,477,3489780.35315.53.01 (0.1)0 (0.0)0 (0.0)Rwanda12,208,40719130.49868.35.01 (0.1)0 (0.0)0 (0.0)Seychelles94,73728,3910.78293.9151.01 (0.1)1 (0.2)0 (0.0)Sierra Leone7,557,21214730.42032.43.01 (0.1)0 (0.0)0 (0.0)Outside AfricaNANANANANA91 (6.9)56 (11.3)2 (40.0)GDP, gross domestic product; HDI, human development index, IF, impact factor; NA, not applicable; pmp, per million population; RCTs, randomized controlled trials. Open table in a new tab Figure 3(a) Number of articles per region in Africa. (b) Number of articles published in journals with an impact factor in Africa.View Large Image Figure ViewerDownload Hi-res image Download (PPT) GDP, gross domestic product; HDI, human development index, IF, impact factor; NA, not applicable; pmp, per million population; RCTs, randomized controlled trials. Table 2 summarizes the types and study designs of included articles. There were 1051 (79.3%) original research (made up of cross-sectional studies [n = 841, 80.0%], cohort studies [n = 114, 10.9%], case-control studies [n = 91, 8.7%], and randomized control trials [n = 5, 0.5%] (Table 2). Articles published in journals with an impact factor (IF) or Scimago Journal Rank (SJR) were 37.3% (median IF = 1.56, interquartile range [IQR] = 0.92−2.39) and 79.6% (median SJR = 0.32, IQR = 0.19−0.65), respectively. Nigeria (21.6%), South Africa (20.8%), and Egypt (14.7%) had the most articles in a journal with an IF (Table 1, Figure 3b). Only 31.8% of the articles were published in a journal with a nephrological or urological scope, and 59.0% were published in journals based in Africa (Table 2).Table 2Types of published articles, study designs, and journal metrics of included articlesTypen (%)Article types (n = 1326) Cross-sectionalaPublished original articles.841 (63.4) Case report165 (12.4) CohortaPublished original articles.114 (8.6) Case controlaPublished original articles.91 (6.9) Review62 (4.7) Randomized controlled trialaPublished original articles.5 (0.4) Case series17 (1.3) Letter16 (1.2) Commentary10 (0.8) Editorial4 (0.3) Images1 (0.08)Study design (n = 1051) Prospective582 (55.4) Retrospective299 (28.5) Prospective and retrospective1 (0.1) Unclear169 (16.1)Journal metrics Impact factor (n = 495), median [IQR]1.56 [0.92–2.39] SJR (n = 1056), median [IQR]0.32 [0.19–0.65]Journal scope (n = 1326) Nephrology/urology422 (31.8) Others904 (68.2)Journal location (n = 1326) Journals based in Africa782 (59.0) Journal based outside of Africa544 (41.0)IQR, interquartile range; SJR, scientific journal ranking.a Published original articles. Open table in a new tab IQR, interquartile range; SJR, scientific journal ranking. Using multivariable linear regression, population was the only sociodemographic factor associated with publications by country (β-coefficient = 1.26, 95% confidence interval [CI] = 0.85−1.68, P < 0.0001) (Table 3). Factors associated with publications in a journal with an IF were as follows: the continent of the journal (adjusted odds ratio [aOR] = 0.08, 95% CI = 0.06−0.11, P < 0.0001), level of income (aOR = 3.59, 95% CI = 2.12−6.08, P < 0.0001), literacy rate (aOR = 1.01, 1.01−1.03, P = 0.004), number of physicians (aOR = 0.60, 95% CI = 0.37−0.98, P = 0.042), population size (aOR = 2.55, 95% CI = 1.82−3.57, P < 0.0001), and number of authors listed in the publication (aOR = 1.11, 95% CI = 1.05−1.17, P = 0.0004) (Table 4).Table 3Factors associated with the number of publications per countryFactorsUnivariable linear regressionMultivariable linear regressionCrude β-coefficient (95% CI)P valueAdjusted β-coefficient (95% CI)P valuePopulation1.28 (0.86 to 1.69)<0.00011.26 (0.85 to 1.68)<0.0001GDP0.002 (−0.002 to 0.007)0.228HDI155.6 (−84.4 to 395.6)0.213Physicians32.2 (−31.4 to 95.8)0.32925.4 (−18.9 to 69.7)0.269Literacy rate0.35 (−0.94 to 1.63)0.602CI, confidence interval; GDP, gross domestic product; HDI, human development index. Open table in a new tab Table 4Factors associated with publishing in a journal with an impact factorFactorsnn (%)Univariate modelMultivariate final modelCrude odds ratio (95% CI)PAdjusted odds ratio (95% CI)PFirst continent of the author Outside of Africa9156 (61.5)1 Africa1209436 (36.1)0.35 (0.23–0.55)<0.00011.13 (0.54–2.33)0.750Types of papers Others27578 (28.4)1 Original articles1051417 (39.7)1.66 (1.25–2.23)<0.0001Continent of the journal Outside of Africa542127 (67.9)1 Africa782368 (16.2)0.09 (0.07–0.12)<0.00010.08 (0.06–0.11)<0.0001Scope of the journal Others904300 (33.2)1 Specific to nephrology/urology422195 (46.2)1.73 (1.37–2.19)<0.0001Country level of income Low- and low-middle1044327 (31.2)1 Upper-middle and high255165 (64.7)4.02 (3.01–5.36)<0.00013.59 (2.12–6.08)<0.0001Country level of HDI Low and medium1139403 (35.4)1 High and very high16089 (55.6)2.29 (1.64–3.20)<0.0001Level of literacy By increase of 10%1.03 (1.03–1.04)<0.00011.01 (1.01–1.03)0.004Number of physicians by 100,000 people By increase of 0.252.17 (1.59–2.95)<0.00010.60 (0.37–0.98)0.042Year of publication ≤200014168 (48.2)1 2000–2009370140 (37.8)0.65 (0.44–0.97) 2010–2017815287 (35.2)0.58 (0.41–0.84)0.013Number of authors By increase of 31.13 (1.09–1.18)<0.00011.11 (1.05–1.17)0.0004Number of inhabitants in the country ≤50 × 106443141 (31.8)1 >50 × 106856351 (41.0)1.49 (1.17–1.90)0.0012.55 (1.82–3.57)<0.0001 Open table in a new tab CI, confidence interval; GDP, gross domestic product; HDI, human development index. This study was carried out to assess the quality and quantity of nephrology research from Africa over the past 5 decades. Our study showed the following: (i) Nigeria (and West Africa), with a very large population, have the highest numbers of nephrology publications: (ii) a relatively low quality of research as evidenced by the low number of randomized controlled trials (RCTs) and publications in journals with low Ifs; and (iii) no correlation among gross domestic product (GPD), human development index (HDI), and literacy rate with number of publications per country in Africa. The reasons for West Africa (and Nigeria) having the highest number of publications may be related to the larger size of the population (and therefore the number of researchers), higher number of medical schools in the region compared to other African regions, 8World Federation for Medical Education and the Foundation for Advancement of International Medical Education and ResearchWorld Directory of Medical Schools.www.wdoms.org/Date: 2016Google Scholar and the large number of biomedical journals in West Africa and Nigeria compared to other regions (https://www.ajol.info/index.php/index/browse/category). Thus, although African Journals OnLine (AJOL) hosts 525 different journals, 42.3% are in Nigeria, which might increase publication opportunities for researchers from Nigeria and West Africa. This could explain why 59% and 68.2% of nephrology publications on the continent are published in journals hosted within Africa and journals with scope outside of nephrology/urology, respectively (Table 2). Although various studies have shown a higher number of nephrologists to be from the North African region compared to other African regions,9Osman M.A. Alrukhaimi M. Ashuntantang G.E. et al.Global nephrology workforce: gaps and opportunities toward a sustainable kidney care system.Kidney Int Suppl. 2018; 8: 52-63Abstract Full Text Full Text PDF PubMed Scopus (95) Google Scholar,S1 the relatively lower number of published studies from North Africa compared to West Africa may be related to language, as most of countries in North Africa are predominantly Arabic- or French-speaking nations. “Brain-drain” of nephrologists with research capacity could also be a contributing factor to the low number and quality of nephrology research outputs from Africa.S2,S3 Many qualified researchers may leave Africa for “greener pastures” in other continents often because of socioeconomic constraints, lack of infrastructure, and desire for personal fulfilment.S4 Although brain drain remains a hefty challenge for developing sustainable research programs in Africa, this can be turned into an opportunity to improve research in Africa, given the number of African-origin nephrology researchers working outside of the continent. The skills of nephrology researchers who have left Africa, irrespective of their locations, can be harnessed to provide training and mentoring and to improve skills and collaboration at local levels to enhance both quantity and quality of research. The initial ways to do this could include invitations and participations at local nephrology meetings, development of research protocols, joint supervision of nephrology trainees, and joint applications for research grants for research. Such partnerships can become immensely critical toward contributing and improving Africa’s healthcare systems and research. Research quality is difficult to quantify; however, given the rigorous editorial and peer review processes of many journals, publications in journals with high impact factors as well as RCTs tend to be appropriately regarded with quality. There were only 0.4% nephrology RCTs recorded over the period of our study.S5−S9 Only a few centers in Africa (mainly South Africa, Egypt, Algeria, and Morocco) have the human and infrastructural capacity to participate in research clinical trialsS10; however, these trials are usually driven by pharmaceutical companies, highlighting the gaps in conducting RCTs in Africa. Notwithstanding that we did not find an association between economic indicators (GDP and HDI) and publication counts, these factors have been known to correlate with scientific productivity.S11,S12 Data from the World Bank shows that most African countries either do not have data on research and development or spend less than 0.5% of national budget on research and development (compared to high-income countries that spend well over 2%).S13 Although most African countries are faced with a double burden of infectious and noncommunicable diseases as well as poverty, there needs to be a substantial increase in spending for healthcare and for scientific research and development; this will have positive outcomes for nephrology research in Africa. There are a few limitations of our study. Our search was limited to PubMed and AJOL; hence, research in other databases could have been missed. However, we are confident to have captured most articles published in the study period. Also, our study is limited by excluding research on kidney disease in conditions known to increase kidney disease risk in Africans (e.g., hypertension, diabetes, and HIV). We did this because research related to these risk factors often describe other associated systemic complications, thus categorizing them as “general medicine.” Finally, although we used “first author” details to describe the country of origin of the research, in every case, we verified the country of the study setting as the country of the research. For review articles in which the African author(s) were not first, last, or corresponding authors, the article was not counted as African research. Despite these limitations, our study still captures the essence of the current state of nephrology research in Africa, thus advocating for measures that improve the amount and quality of nephrology research from the continent. This requires an increase in resource allocation for kidney disease research and training. All the authors declared no competing interests. JJN is supported by a Postgraduate Scholarship from the University of Adelaide. The authors are grateful to Dr. Mazou N. Temgoua for his contributions. Download .pdf (.12 MB) Help with pdf files Supplementary File (PDF)

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