Diabetes Research in India, China and Brazil: A Comparative Quantitative Study, 2000-09

Diabetes is a chronic disease that occurs when the pancreas does not produce enough insulin or when the body cannot effectively use the insulin it produces. Diabetes is a life-threatening condition affecting millions of people. Diabetes is a major threat to global public health that is rapidly getting worse, and the biggest impact is on adults of working age in developing countries. Diabetes is a common condition and its frequency is dramatically rising all over the world. Although diabetes is sometimes considered a condition of developed nations, the loss of life from premature death among persons with diabetes is greatest in developing countries [1].


Introduction
Diabetes is a chronic disease that occurs when the pancreas does not produce enough insulin or when the body cannot effectively use the insulin it produces.Diabetes is a life-threatening condition affecting millions of people.Diabetes is a major threat to global public health that is rapidly getting worse, and the biggest impact is on adults of working age in developing countries.Diabetes is a common condition and its frequency is dramatically rising all over the world.Although diabetes is sometimes considered a condition of developed nations, the loss of life from premature death among persons with diabetes is greatest in developing countries [1].
According to International Diabetic Federation (IDF), the low-and middle-income countries face the greatest burden of diabetes.It is one of the major causes of premature illness and death in most countries.It is estimated that around 330,000 deaths will be attributable to diabetes in 2010 and shows a 5.5% increase over the estimates for the year 2007 [2].Diabetes imposes a large economic burden on the individual, national healthcare system and economy.Healthcare expenditures on diabetes are expected to account for 11.6% of the total healthcare expenditure in the world in 2010.As per IDF estimates, healthcare expenditures to treat and prevent diabetes and its complications are expected to total at least USD 376 billion in 2010.By 2030, this number is projected to exceed some USD 490 billion [2].
In 1985, the best data available suggested that 30 million people had diabetes worldwide.Fast-forward 15 years and the numbers were revised to just over 150 million.Today, less than 10 years on, the new figures -launched at the 20 th World Diabetes Congress in Montreal, Canada -put the number closer to 300 million, with more than half aged between 20 and 60.IDF predicts that, if the current rate of growth continues unchecked, the total number will exceed 435 million in 2030 -many more people than the current population of North America.Diabetes now affects seven percent of the world's adult population.The regions with the highest comparative prevalence rates are North America, where 10.2% of the adult population have diabetes, followed by the Middle East and North Africa Region with 9.3%.The regions with the highest number of people living with diabetes are Western Pacific, where some 77 million people have diabetes and South East Asia with 59 million.India is the country with the most people with diabetes, with a current figure of 50.8 million, followed by China with 43.2 million.Behind them the United States (26.8 million); the Russian Federation (9.6 million); Brazil (7.6 million); Germany (7.5 million); Pakistan (7.1 million); Japan (7.1 million); Indonesia (7 million) and Mexico (6.8 million).When it comes to the percentage of adult population living with diabetes, the new data reveal the devastating impact of diabetes across the Gulf Region, where five of the Gulf States are among the top ten countries affected.The Pacific island nation of Nauru has the world's highest rate of diabetes, with almost a third of its adult population (30.9%) living with the disease.It is followed by the United Arab Emirates (18.7%);Saudi Arabia (16.8%);Mauritius (16.2%);Bahrain (15.4%);Reunion (15.3%);Kuwait (14.6%);Oman (13.4%);Tonga (13.4%) and Malaysia (11.6%) [3].

Literature Review
A few studies have been conducted in measuring the progress of the research in diabetes worldwide and in Indian context in the past.Lewin [4] studied world diabetes mellitus publications during 1984-2005, using MEDLINE database and indicated that the publication growth of articles parallels the increase in diagnosed cases of diabetes mellitus (both type 1 and type 2 together) and the literature relating to type 1 diabetes mellitus has saturated, while that of type 2 showed the increase over time.Apoor, Montori, Wilczynski, and Haynes [5] studied author self-citation in the diabetes literature.Krishnamoorthy et al. [6] studied world diabetes literature during 1995-2004, using MEDLINE database.Somogyl and Schubert [7] made an interesting correlation between national bibliometric and health indicators in diabetes.

Aims and Objectives
The main objective of this study is to analyze the diabetes research in India, China and Brazil, as reflected in its publications output during 2000-09.In particular, the study focuses on the following objectives: (i) To study the research output, publication share, rank and global burden of the diabetes of most productive countries of the world, (ii) To study the research output, growth and citation impact of research in India, China and Brazil, (iii) to study the patterns of international collaboration of India, China and Brazil and (iv) To study research profile of leading institutions of India, China and Brazil.

Methodology and Source of Data
The Scopus Citation database has been used for retrieving the publication data in diabetes research for the 10 years (2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009).For citations data, three years, two years and one year citations window has been used for computing average citations per paper during 2000-2007, 2008 and 2009.The search strategy on diabetes literature was carried out using the following key words strategy suggested by Arunachalam and Gunasekaran [8], Ratnakar and Satyanarayana [9] and Rosalind A. Maria [10].For identifying literature on three types of diabetes and for different diabetes complications, different keywords strategies were developed.For calculating the international collaborative papers, a separate search strategy was prepared.

Analysis Research output of most productive countries
In overall, the global publications share of top 16 most productive countries in diabetes research vary from 1.29% to 29.25% during the ten years period (2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009).Among these 16 most productive countries in diabetes research, USA scored 1 st rank, with global publications share of 29.25%.UK comes at 2 nd rank with 8.50% global publications share, followed by Japan, Germany, Italy, France and China (with their global publications share ranging from 3.48% to 6.27%).Spain, Netherlands, Sweden and India ranks at 8 th to 11 th positions, with their global publications share varying from 2.13% to 2.96% during 2000-09.The countries that rank between 12 th to 16 th positions are Switzerland, S. Korea, Brazil, Turkey and Belgium with their global publications share less than 2% (varying from 1.29% to 1.45%) (Table 1).
On analyzing the shift in ranking of these 16 countries from 2000 to 2009, it was found that USA, UK, Japan and Germany continue to rank at 1 st to 4 th positions, in spite of decline in their publications share from the year 2000 to the year 2009.Among the developing countries China, India, South Korea and Brazil witnessed the major shift in their ranking from 13 th to 5 th , 11 th to 9 th , 14 th to 12 th and 16 th to 13 th , respectively due to the increase in their global publications share from the year 2000 to the year 2009.

Research productivity and burden of disease in global context
Based on the percentage of population suffering from diabetes, these 16 most productive countries have been categorized into Highest (with diabetic population from 8.1% to 12.3%), Medium (with diabetic population from 5% to 8.0%) and Lowest (with diabetic population from less than 5%) affected countries.Similarly countries are classified according to publications intensity as High (with papers per million populations varying from 460 to 966), Medium (with papers per million populations varying from 238 to 369) and Low (with papers per million populations less than 200) (Table 2).Sweden, Netherlands, Switzerland, UK and Belgium) are found to have generally low to medium prevalence of diabetes (varying from 4.9% to 8.0%) in contrast to medium publications intensity countries (namely UK, Germany, France, Italy and Spain) having high prevalence of diabetes (varying from 8.7% to 12.3%).As against these two groups of countries, low publication intensity countries (namely Japan, Turkey, India, Brazil and China) have low to medium prevalence of diabetes (varying from 4.5% to 7.4%).In this group, South Korea is the only exception with having high prevalence (9%) of diabetes (Table 2).

Research profile of India, China and Brazil in diabetes research
On analyzing the diabetes research profile of India, China and Brazil, it was found that China witnessed the highest publications output with 9520 papers in diabetes research, in contrast to India and Brazil's publication output of 5843 papers and 3907 papers respectively during 2000-09.In terms of cumulative growth of diabetes research publications from 2000-04 to 2005-09, China achieved the highest growth rate of 244.24%, followed by Brazil (172.45%) and India (122.64%)(Table 3).
Considering the quality and impact of papers (measured in terms of the citations received per paper on a three year window), Brazil scored the highest impact of 6.64, followed by India (4.59) and China (3.82).Among these three countries, Brazil and India witnessed decline in its citation impact from 7.24 to 6.42 and 4.62 to 4.58 citations, respectively in contrast to increase in China from 3.73 to 3.85 citations from 2000-04 to 2005-09 (Table 4).
Considering the international collaboration publications output, China achieved the highest international collaborative publication share of 20.88% during 2000-09, followed by Brazil (20.86%) and India (12.54%).The international collaborative publications share of all the three countries has increased from 2000-04 to 2005-09: India (from 10.65% to 13.39%),China (from 18.21% to 21.90%) and Brazil (from 20.59% to 20.95%).The international collaborative research output of Brazil witnessed the highest citations impact per paper of 16.13, followed by India (9.65) and China (9.26).Among these three countries, the citation impact per paper of India increased from 8.83 to 9.94 from 2000-04 to 2005-09, as against decrease from 11.17 to 8.82 in China and 17.39 to 15.68 in Brazil (Table 5).

Subject wise research priorities of India, China and Brazil
In terms of research priorities, the largest emphasis (72.67%) has been given to medicine in world output in diabetes, followed by Biochemistry

Research output of India, China and Brazil under types of diabetes
Diabetes research output on different types of diabetes shows that the maximum research output in these counties comes from Type 2 diabetes with publications share varying from 16.18% to 21.09%, followed by Type 1 diabetes with publications share varying from 4.84% to 9.54% and gestational diabetes with publications share varying from 0.97% to 2.48% during 2000-09.In Type 2 diabetes, India contributes the highest share of 21.09%, followed by China (20.66%) and Brazil (16.18%).In Type 1 diabetes, Brazil contributes highest share of 9.34%, followed by India (5.51%) and China (4.84%).In gestational diabetes, Brazil contributes the highest share of 2.48%, followed by India (1.92%) and China (0.97%) (Table 9).
The Brazil achieved the highest citation impact per paper of 5.22 and 8.84 in Type 1 diabetes and Type 2 diabetes, followed by India (4.73 and 5.61) and China (3.74 and 3.76) during 2000-09.In gestational diabetes, India achieved the highest citation impact per paper of 3.61, followed by Brazil (3.09) and China (2.30) during 2000-09.

Diabetic complications and research output of India, China and Brazil
In terms of diabetic complications in research as reflected in world output, the largest emphasis has on heart with publications share of 38.99% during 2000-09, followed by kidney (25.56%), eye (11.13% share), nervous system (9.94% share), brain (8.52% share), foot (5.61% share) and tooth (0.25% share).
On analyzing the diabetic complications in research among India, China and Brazil research output in terms of their publications relative index, it was found that eye, neuropathy and kidney complications with activity index of 1.60, 1.37 and 1.20 showed above world average in India, eye and kidney complications with activity index of 2.16 and 1.20 in China and tooth, eye, kidney, neuropathy and heart complications with activity index of 2.31, 1.18, 1.16, 1.10 and 1.09 in Brazil (Table 12).
Considering the impact of these three countries on diabetic complications, (i) Brazil witnessed the highest citations impact per paper of 9.54 on heart, followed by India (4.81) and China (4.23), (ii) Brazil witnessed the highest citations impact per paper of 8.95 on eye, followed by India (4.25) and China (1.62), (iii) Brazil witnessed the highest citations impact per paper of 7.69 on kidney, followed by India (4.81) and China (4.23), (iv) Brazil witnessed the highest citations impact per paper of 6.26 on neuropathy, followed by India (4.10) and China (2.35), (v) China witnessed the highest citations impact per paper of 3.67 on tooth, followed by Brazil (1.00) and India (0.40), (vi) India witnessed the highest citations impact per paper of 1.75 on foot, followed by Brazil (10.61) and China (0.56) (Table 13).

Research profile of prolific institutions of India, China and Brazil
The research profile of 10 most productive institutions in diabetic

Conclusion
There is an urgent need for governments to face the challenge of diabetes epidemic.At the same time, investments must be made in diabetes R&D, care and management, including diabetes education, to enable the millions of people with diabetes to lead full and productive lives.There is a need to develop new training courses and develop sufficient trained manpower, besides increasing the international collaboration efforts in this area.Diagnosis, treatment, management and prevention of diabetes require integrated health systems, delivery of care down to primary care level, and supportive policies outside the health sector.System-level changes and improvement in political and organizational environment is required within which diabetes care is provided.

Table 1 :
Global publications output, publications share and rank of top 16 most productive countries in diabetes research, 2000-2009.Volume 3 • Issue 2 • 1000110 J Health Med Inform ISSN:2157-7420 JHMI, an open access journal

Country 2010 Population (20-79) years 000's10 DM population and percent share of Diabetic population of productive countries Prevalence 2010 National (%)10 Total Papers Papers per Million Population
On comparing research emphasis of the India, China and Brazil vis-à-vis the world, it was observed that Pharmacology, Toxicology & Pharmaceutics, Agricultural & Biological Sciences and Chemistry has a higher share, compared to the lower share of Medicine, Biochemistry, Genetics & Molecular Biology, Neurosciences and Immunology & Microbiology in India during 2000-09.In China, comparatively more emphasis has been placed on Pharmacology, Toxicology & Pharmaceutics and Chemistry, compared to lower emphasis on Medicine, Biochemistry, Genetics & Molecular Biology, Agricultural & Biological Sciences, Neurosciences and Immunology & Microbiology.In Brazil, more emphasis has been placed on Pharmacology, Toxicology & Pharmaceutics, Agricultural & Biological Sciences, Neurosciences and Immunology & Microbiology compared to less emphasis on Medicine, Biochemistry, Genetics & Molecular Biology and Chemistry (Table7).

Table 2 :
Publication output per million population and percent share of diabetic population of most productive countries.

Table 3 :
Annual growth of papers in diabetes research, 2000-09.
TP: Total Papers; TC: Total Citations; ICP: International Collaborative Papers

Table 4 :
Publication output and citation impact of India, China and Brazil in diabetes research, 2000-2009.

Table 5 :
Citation impact of international collaborative papers of India, China and Brazil in diabetes research, 2000-2009.

Table 6 :
Subject-wise break-up of papers of India, China and Brazil in diabetic research, 2000-09.
by India (4.48) and China (3.18); (ii) in Biochemistry, Genetics & Molecular Biology, Brazil made the highest citation impact per paper of 7.22, followed by China (5.45) and India (5.28); (iii) in Pharmacology, Toxicology & Pharmaceutics, Brazil made the highest citation impact per paper of 4.9, followed by India (4.55) and China (4.31); (iv) in Agricultural & Biological Sciences, China made the highest citation in Chemistry, Brazil made the highest citation impact per paper of 7.12, followed by China (5.89) and India (5.8 zil 7); (vi) in Neurosciences, China made the highest citation impact per paper of 5.81, followed by India (5.55) and Brazil (5.06) and (vii) in Immunology & Biology, Brazil made the highest citation impact per paper of 7.65, followed by India (5.04) and China (4.77) (Table8).

Table 7 :
Relative index of publication output in diabetes research under different subjects, 2000-2009.
TP: Total Papers; TC: Total Citations; ACPP: Average Citations per Paper

Table 8 :
Publication output and impact in diabetes research under different subjects, 2000-09.

Table 9 :
Publication share of different types of diabetes, 2000-09.

Table 10 :
Publication output and impact in diabetes research under different types of diabetes during 2000-2009.

Table 11 :
Share of publication output in diabetic complications during 2000-2009.

Table 12 :
Relative index of publication output in diabetic complications during 2000-2009.

Table 13 :
Publication output and impact in diabetic complications research during 2000-2009.
TP: Total Papers; TC: Total Citations; ACPP: Average Citations per Paper

Table 14 :
Publication output, impact and H-Index of productive institutions of India in diabetic research during 2000-2009.

Table 15 :
Publication output, impact and H-Index of productive institutions of China in diabetic research during 2000-2009.
TP: Total Papers; TC: Total Citations; ACPP: Average Citations per Paper

Table 16 :
Publication output, impact and H-Index of productive institutions of Brazil in diabetic research during 2000-2009.