The paper analyzes Parkinson’s disease research publications output by India in the global context using bibliometric indicators with the purpose to assess and evaluate the research productivity and impact of the country in the subject. The publications data for study was sourced from the Scopus database covering the 30-year period 1990-2019. The study reveals that the global research in the domain of Parkinsons’s disease is highly skewed. The top 15 most productive countries in the subject account for a 99.59% global publications share. The USA is the world leader in the subject with a 31.71% global share, followed by U.K., Germany, Italy, Japan and China (from 6.16% to 10.20%), etc. India ranks as the 13th most productive country in the world with a global publications share of 2.35% (3149 publications). India registered a 22% annual growth rate in the subject, averaged citation impact of 19.08 citations per paper, and published 21.88% of its country output as a share of international collaborative papers. The paper identifies most productive organizations, most cited organizations, most productive authors, and most cited authors. The paper also identifies the most productive journals and the most cited journals.
Bibliometrics; Indian publications; Parkinson’s disease; Scientometrics
Parkinson’s Disease (PD) is recognized as the most common age-related movement disorder and the second most common neurodegenerative disease [1-3]. As the PD disease worsens, non-motor symptoms begin to impact the quality of life [4,5]. The pathological features of the Parkinson disease result from the substantial cell loss or cell deaths in the substantianigra (a region of the midbrain) [4] and the concomitant loss of Dopamine (DA) neurotransmitter or not enough dopamine in this region of the brain. Though the cause of cell death is poorly understood, but it does involve the build-up or deposition of proteins within the brain as intracellular inclusions called Lewy bodies in the neurons [4,6,7]. The disease is clinically manifested after the death of ~70% of these neurons [4,6]. The symptoms usually emerge slowly [4]. Early in the disease, the most obvious symptoms are shaking, rigidity, slowness of movement, and difficulty with walking [4]. Thinking and behavioral problems may also occur [2]. Dementia becomes common in the advanced stages of the disease [7]. Depression and anxiety are also common, occurring in more than a third of people with PD [5]. Other symptoms include sensory, sleep, and emotional problems [1,2]. The main motor symptoms are collectively called "parkinsonism” or a "parkinsonian syndrome" [4,6].
Parkinson disease has been the subject of intense research across the world ever since it was first discovered around 200 years ago. The literature in the subject has by far grown significantly in volume. Among the bibliometric studies at international level, Xue, Hu, Lai, Cai and Wen [8] studied 100 most-cited articles (receiving 669 to 6902 citations per paper and appearing between 1996 and 2000) on Parkinson’s disease to evaluate research on metrics such as citation number, publication time, journal, impact factor, authors, original country, institution of corresponding author and study type. Li, Ho and Li [9] assessed quantitative and qualitative global trends in Parkinson's disease literature 1991-2006 on measures such as scientific output, world collaboration, and the frequency of author keywords used. The keywords analysis helped to identify research trends and recent hot spots. Yang, Wang, Tang, Wang and Bao [10] examined publication trends in stem-cell research in the context of Parkinson's disease and studied the bibliometric characteristics of top-cited articles, published between 1999 and 2018, on metrics such as annual outputs, distribution by journals, countries/regions, and institutions. The authors also studied global collaborations between publications and tracked the growing hotspots using MeSH terms.At the national level, Gupta and Bala [11] examined the research output of India in Parkinson's Disease (PD) during 2002-2011. The bibliometric indicators used for analysis include: Research output, research growth, country rank in global publications, citation impact, international collaboration, major collaborators and publication productivity. They also analyzed research output by subject sub-fields and described bibliometrics characteristics of the leading institutions and authors and of highly-cited papers in the subject.
The data for the present study was sourced from the Scopus database. It is one of the most reliable international multidisciplinary citation databases (http://www.scopus.com) by Elsevier Science and most widely used for bibliometric studies [12]. The Scopus has a slight edge in the coverage of health sciences, medicine and environmental science journals over the Web of Science or PubMed [13]. The strategy applied for data retrieval was as follows. Here, the keyword “Parkinson*” was suffixed to search tags -- “Key” (Keyword) and “Title” (Title of Paper) -- and the time frame for search output was limited to -- 1990 till June, 2019. This main search strategy so formulated yielded a total of 208902 records as the world output in the subject. The global search output was refined manually to 133731 records. The final search output was further refined by country of publication (including India) to identify the top 15 most productive countries in the domain of Parkinson’s disease research. The search string (shown below) for sourcing India’s output in the subject yielded 3149 records. These records were further analyzed by document types including original articles, reviews, letters and editorials, etc [14-17].
(KEY(Parkinson*) or TITLE (Parkinson*)) and PUBYEAR > 1989 AND PUBYEAR < 2020 and (LIMIT-TO (AFFILCOUNTRY,"India"))
Overall publication output & growth
As seen from Scopus database, the global research in the domain of Parkinson disease accumulated a total of 133731 publications during the 30-year period 1990-2019, with an average of 4457.7 papers per year. During the period, India contributed a 2.35% share (3139 publications) to the global publications output, with an average of 104.6 papers per year, and registered 22% annual growth compared to world average of 7.06% in the subject. Compared to 15-year absolute growth (108.34%) registered by the world between 1990-2004 and 2005-2019, the corresponding growth by India in the subject was ten times faster (1080.08%). This sort of growth trend in the data seeks to reveal that India’s growth in the 2nd half of the study period was significantly faster compared to its 1st half. The citation impact of India averaged to 19.08 citations per paper (CPP) during 1990-2019 (Table 1, Figure 1).
Publication Period |
World |
India |
|||||
TP |
TP |
TC |
CPP |
TP (%) |
ICP |
ICP (%) |
|
1990 |
1524 |
7 |
51 |
7.29 |
0.46 |
0 |
0 |
1991 |
1420 |
10 |
64 |
6.4 |
0.7 |
1 |
10 |
1992 |
1650 |
5 |
68 |
13.6 |
0.3 |
0 |
0 |
1993 |
1738 |
3 |
19 |
6.33 |
0.17 |
1 |
33.33 |
1994 |
1724 |
7 |
195 |
27.86 |
0.41 |
3 |
42.86 |
1995 |
1908 |
11 |
291 |
26.45 |
0.58 |
1 |
9.09 |
1996 |
1935 |
8 |
105 |
13.13 |
0.41 |
4 |
50 |
1997 |
2254 |
17 |
440 |
25.88 |
0.75 |
1 |
5.88 |
1998 |
2296 |
13 |
312 |
24 |
0.57 |
1 |
7.69 |
1999 |
1638 |
13 |
325 |
25 |
0.79 |
3 |
23.08 |
2000 |
2884 |
25 |
593 |
23.72 |
0.87 |
1 |
4 |
2001 |
2887 |
24 |
401 |
16.71 |
0.83 |
5 |
20.83 |
2002 |
3338 |
20 |
804 |
40.2 |
0.6 |
3 |
15 |
2003 |
3839 |
43 |
1931 |
44.91 |
1.12 |
6 |
13.95 |
2004 |
4126 |
40 |
1263 |
31.58 |
0.97 |
8 |
20 |
2005 |
4374 |
50 |
2804 |
56.08 |
1.14 |
14 |
28 |
2006 |
4739 |
63 |
2441 |
38.75 |
1.33 |
11 |
17.46 |
2007 |
5057 |
69 |
1850 |
26.81 |
1.36 |
12 |
17.39 |
2008 |
5280 |
76 |
1912 |
25.16 |
1.44 |
18 |
23.68 |
2009 |
5620 |
104 |
4597 |
44.2 |
1.85 |
20 |
19.23 |
2010 |
6149 |
136 |
4204 |
30.91 |
2.21 |
23 |
16.91 |
2011 |
6456 |
141 |
2932 |
20.79 |
2.18 |
28 |
19.86 |
2012 |
6998 |
174 |
3471 |
19.95 |
2.49 |
36 |
20.69 |
2013 |
7164 |
195 |
4467 |
22.91 |
2.72 |
44 |
22.56 |
2014 |
7009 |
249 |
5445 |
21.87 |
3.55 |
50 |
20.08 |
2015 |
7339 |
242 |
7213 |
29.81 |
3.3 |
54 |
22.31 |
2016 |
7756 |
317 |
3204 |
10.11 |
4.09 |
66 |
20.82 |
2017 |
7957 |
321 |
6002 |
18.7 |
4.03 |
71 |
22.12 |
2018 |
8149 |
386 |
1924 |
4.98 |
4.74 |
99 |
25.65 |
2019 |
8523 |
380 |
749 |
1.97 |
4.46 |
105 |
27.63 |
1990-2004 |
35161 |
246 |
6862 |
27.89 |
0.7 |
38 |
15.45 |
2005-2019 |
98570 |
2903 |
53215 |
18.33 |
2.95 |
651 |
22.43 |
1990-2019 |
133731 |
3149 |
60077 |
19.08 |
2.35 |
689 |
21.88 |
Table 1: India Vs World - Publication Output and Citations Count in Parkinson’s Disease Studies, 1990-2019.
Note: TP-Total papers; TC-Total citations; CPP-Citations per paper; ICP-International collaborative papers.
Figure 1: Parkinson disease research studies- Global Vs India 1990 -2019.
During the period under study, the bulk of the publications output by India appeared as articles and reviews (61.19% and 22.61% share), and the rest was distributed across other publication types: conference papers, letters, book chapters, editorials, notes, short surveys, erratum etc.
India collaborated with a total of 160 foreign countries in its research pursuits in Parkinson disease. It published 21.88% of its output (689) as a share of International Collaborative Publications (ICP). The citation impact of the ICP publications by India was 35.12 citations per paper, nearly twice that of the country average (19.08) during the period. The USA was the largest collaborating partner with India with a 46.08% share of total ICP publications by the country, followed by U.K. (13.21%), Australia (9.72%), Saudi Arabia (9.43%) and others.
Of the 3198 publications by India on Parkinson’s disease during 1990-2019, 3108 (98.70%) were the outcome from research projects supported by funding from 140 Indian and foreign funding agencies. CSIR funded for the largest number of papers (116), followed by ICMR (102 papers), Kerala, DST, India (95 papers), etc. Among the foreign funding agencies, Bangladesh Council of Scientific & Industrial Research funded 132 papers, National Institute of Health, USA (48 papers), etc.
On classifying India’s Parkinson’s disease research output by age groups of target population, it was found that “Adults” constituted the largest research category of target population, followed by “Middle Aged” (13.02%), “Aged” (12.70%), “Adolescents” (3.24%) and Children’s (2.41%) during 1990-2019 (Table 2).
S.No |
Target Population Age Group |
Number of Papers |
Share of Papers |
||||
1990-2004 |
2005-2019 |
1990-2019 |
1990-2004 |
2005-2019 |
1990-2019 |
||
1 |
Adults |
90 |
624 |
714 |
36.59 |
21.50 |
22.67 |
2 |
Middle Aged |
48 |
362 |
410 |
19.51 |
12.47 |
13.02 |
3 |
Aged |
41 |
359 |
400 |
16.67 |
12.37 |
12.70 |
4 |
Adolescents |
20 |
82 |
102 |
8.13 |
2.82 |
3.24 |
5 |
Children’s |
15 |
61 |
76 |
6.10 |
2.10 |
2.41 |
6* |
TOTAL |
246 |
2903 |
3149 |
100.00 |
100.00 |
100.00 |
7* |
ACTUAL TOTAL |
214 |
1488 |
1702 |
87 |
51.26 |
54.04 |
Table 2: Break-up of Research Papers by Age Groups of Target Population.
Top 10 countries in research studies on Parkinson ’s disease
More than 100 countries participated in global research in the domain of Parkinson’s disease (133731 papers). Of these, the top 15 countries contributed a 99.59% share to the global output in 30-year during 1990-2019. The USA contributed a 31.71% global share, followed by U.K., Germany, Italy, Japan and China (from 6.16% to 10.20%), Canada, France and Spain (from 4.59% to 5.24%), Australia, Netherlands, Sweden, India, South Korea and Brazil (from 1.82% to 2.95%) during 1990-2019. During the 15-year study period (1990-2004 and 2005-2019), 11 of top 15 countries (namely China, India, South Korea, Brazil, Italy, Australia, Spain, Netherlands, Germany, Canada and Sweden) witnessed marginal jump in their global share by 0.23% to 6.40%, where as 4 other countries (namely U.K., USA, France and Japan) witnessed marginal dip in their global share by 0.46% to 3.47%. (Table 3, Fugure 2).
S.No |
Name of the Country |
Number of Papers |
Share of Papers |
||||
1990-2004 |
2005-2019 |
1990-2019 |
1990-2004 |
2005-2019 |
1990-2019 |
||
1 |
USA |
11476 |
30936 |
42412 |
32.64 |
31.38 |
31.71 |
2 |
U.K. |
3708 |
9939 |
13647 |
10.55 |
10.08 |
10.2 |
3 |
Germany |
2863 |
8356 |
11219 |
8.14 |
8.48 |
8.39 |
4 |
Italy |
2111 |
7537 |
9648 |
6 |
7.65 |
7.21 |
5 |
Japan |
3114 |
5313 |
8427 |
8.86 |
5.39 |
6.3 |
6 |
China |
505 |
7728 |
8233 |
1.44 |
7.84 |
6.16 |
7 |
Canada |
1776 |
5237 |
7013 |
5.05 |
5.31 |
5.24 |
8 |
France |
2161 |
4737 |
6898 |
6.15 |
4.81 |
5.16 |
9 |
Spain |
1318 |
4819 |
6137 |
3.75 |
4.89 |
4.59 |
10 |
Australia |
682 |
3259 |
3941 |
1.94 |
3.31 |
2.95 |
11 |
Netherlands |
886 |
2961 |
3847 |
2.52 |
3 |
2.88 |
12 |
Sweden |
807 |
2489 |
3296 |
2.3 |
2.53 |
2.46 |
13 |
India |
246 |
2903 |
3149 |
0.7 |
2.95 |
2.35 |
14 |
South Korea |
214 |
2665 |
2879 |
0.61 |
2.7 |
2.15 |
15 |
Brazil |
210 |
2230 |
2440 |
0.6 |
2.26 |
1.82 |
Total of top 15 countries |
32077 |
101109 |
133186 |
91.23 |
102.58 |
99.59 |
|
Total of world |
35161 |
98570 |
133731 |
Table 3: Top 15 Most Productive Countries on Parkinson’s disease during 1990-2019.
Figure 2: Distribution of Parkinson's Disease by Country of Publication 1990-19.
Subject-wise distribution of research output
In all, Parkinson’s disease research studies by India are distributed by the Scopus classification across nine subject areas. Of these, medicine accounted for the largest publication share (45.47%), followed by neuroscience (30.84%), biochemistry, genetics & molecular biology (26.42% share), pharmacology, toxicology & pharmaceutics (25.69% share) and the other five subjects (computer science, engineering, chemistry, agricultural & biological Sciences and immunology & microbiology) contributed between 1.97% to 6.80% sharerespectivelys of the country output.
The research activity index of each subject, computed for two select periods viz 1990-2004 and 2005-2019, was found to differ quantitatively. The world average AI for a given subject is always 100. With reference to the world average index, the activity index in three subject areas (medicine, neuroscience, agriculture & biological science) dipped from a high level between (110.78 - 148.39) in 1990-2004 to a level below the world average between (95.9 - 99.09) in 2005-2019. In 6 other areas, their activity index spiked from a low-end level between (5.98 - 87.68) in 1990-2004 to a level well above the world average between (101-04 -107.97) in 2005-2019. This shows that research activity in all of the nine subject areas has been dynamic and changing with the changing times. The 5-yearly average growth was the lowest in engineering discipline (95.47%) and the highest in computer science (275.10%) (Figures 3 and 4).
Figure 3: Parkinson's Disease Research - Change in Activity Index between 1990-2004 & 2005-2019.
Figure 4: Parkinson Disease Research - 5-Yearly Growth in Related Subject Areas 1990-2019.
Distribution of research output by Types of Parkinson’s disease: Parkinson’s disease has been classified as primary and secondary. The primary Idiopathic disease yielded only 75 records and the main emphasis was on Secondary Atypical disease in India. A break-up of India’s publication on various types of Parkinson’s disease is shown in Figure 5.
Figure 5: Distribution of Parkinson Disease Research by Parkinson Disease Type - 1990-2019.
Significant keywords
As seen from the Scopus database, a total of 269 keywords seem to define and identify India’s literature on Parkinson’s disease as well as give some idea about the broad research trends in the treatment and investigation of the disease (Table 4, Figure 6). These keywords have been classified under broad subject headings along with the frequency of keyword occurrence.
Broad Term |
Neuroprotection (453), Neurodegenerative Diseases (357), Degenerative Disease (294) Neurologic Disease (166) Neuroprotective Agent (164) Neurotoxicity (183) Neurodegeneration (124), Parkinsonism (560), Parkinsonian Disorders (190) |
Specific to Parkinson’s disease |
Parkinson Disease (2118), Parkinson's Disease (1106) |
Oxidation Related |
Oxidative Stress (547) Anti-oxidants(250), Anti-oxidant Activity (243) Reactive Oxygen Metabolite (182) |
Pahology Related |
Pathophysiology (277) Pathogenesis (165)) Neuropathology (85) |
Protein Related |
Protein Expression (276), Alpha Synuclein (276), Protein Aggregation (153) |
Enzyme Related |
Enzyme Activity (235) Glutathione (220), Superoxide Dismutase (189) Enzyme Inhibition (84), Catalase (169) |
Medications |
Levodopa (408) Carbidopa Plus Levodopa (88) Rotenone (107) Oxidopamine (108) Haloperidol (107) Carbidopa (74) Monoamine Oxidase Inhibitor (37) Bromocriptine (71) Pramipexole (77) Ropinirole (82) Apomorphine (52), Selegiline(85) Rasagiline (47) Amantadine (82) |
Genetic Related |
Genetics (221) Gene Expression (124) Gene Mutation(115), Gene Expression Regulation (58), Single Nucleotide Polymorphism (56) Genetic Association (50), Messenger RNA (50), Genetic Predisposition (49) Genotype (45), Genetic Variability (44) |
Imaging |
Nuclear Magnetic Resonance Imaging (210) Magnetic Resonance Imaging (90) Neuroimaging (99) Positron-Emission Tomography (36) Single Photon Emission Computed Tomography (21) Computer Assisted Tomography (67) |
Brain & Parts |
Dopamine (398), Brain (253), Dopaminergic Nerve Cell (245) Nerve Degeneration (186) SubstantiaNigra (213) Neurons (151) Dopaminergic Neurons (110) Nerve Cell (117) Basal Ganglion (71) |
Other related Diseases |
Alzheimer Disease (593) Diabetes Mellitus (152) Schizophrenia (152), Epilepsy (134) Multiple Sclerosis (124) Amyotrophic Lateral Sclerosis (173) Cerebrovascular Accident (93) |
Motor Dyfunctions |
Motor Dysfunction (203), Motor Activity (106) Bradykinesia (119), Dyskinesia (116) Cognitive Defect (146) Tremor (169) Muscular Dystrophy (16) Spinal Muscular Atrophy (10) Postural Balance(9) |
Non-Motor Dyfunctions |
Dementia (120), Dystonia (118) Olfactory Bulb (12) Speech Disorder (27) Restless Legs Syndrome(22) Impulse Control Disorder (15) Memory Disorder (43) Respiratory Chain (18) Autonomic Dysfunction (22) Mental Disease (32) Depression (226) Anxiety (56) Sleep Disorder (62) Psychosis (75) Orthostatic Hypotension (9) |
Surgery |
Brain Depth Stimulation (104) Neurosurgery (34) |
Others |
Apoptosis (203) Corpus Striatum (197) Signal Transduction (172) Mitochondria (137) Drug Delivery System (128) Tyrosine 3 Monooxygenase (128) Mitochondrion (124) Hypertension(120) Risk Factor (113) Catalase (169) Animal Model (152) |
Table 4: Significant Keywords Distributed by Broad Categories defining Parkinson’s disease Literature from India during 1990-2019.
Figure 6: Parkinson's Disease Research - Top 25 Keywords for Literature Retrieval 1990-2019.
Top 10 most productive & cited organizations in India
The scientometric profile of top 10 most productive and top 10 most cited organization is presented in Table 5. In all, a total of 700 organizations from India participated in Parkinson’s disease research during 1990-2019. The top 50 most productive organizations contributed 62.95% share (1982) to the country output in the subject. Their productivity varied from 16 to 210 publications per organization.
S.No |
Name of the Organization |
TP |
TC |
CPP |
HI |
ICP |
ICP (%) |
RCI |
Top 10 Most Productive Organizations |
||||||||
1 |
National Institute of Mental Health & Neurosciences (NIMHANS), Bangalore |
210 |
3870 |
18.43 |
36 |
44 |
20.95 |
0.97 |
2 |
All India Institute of Medical Sciences (AIIMS), New Delhi |
162 |
9032 |
55.75 |
26 |
24 |
14.81 |
2.92 |
3 |
Indian Instiyute of Toxicologi, Lucknowcal Research (IITR) |
101 |
5903 |
58.45 |
31 |
17 |
16.83 |
3.06 |
4 |
Postgraduate Institute of Medical Education & Research (PGIMER), Chandiagrh |
75 |
7597 |
101.3 |
16 |
12 |
16 |
5.31 |
5 |
Indian Institute of Chemical Biology (IICB), Kolkata |
75 |
2037 |
27.16 |
24 |
23 |
30.67 |
1.42 |
6 |
JamiaHamdard University, Delhi |
69 |
2692 |
39.01 |
27 |
27 |
39.13 |
2.04 |
7 |
Annamalia University |
61 |
1335 |
21.89 |
21 |
31 |
50.82 |
1.15 |
8 |
Central Drug Research Institute (CDRI), Lucknow |
58 |
1180 |
20.34 |
20 |
9 |
15.52 |
1.07 |
9 |
Panjab University, Chandigarh |
57 |
4881 |
85.63 |
19 |
6 |
10.53 |
4.49 |
10 |
SreeChitraTirunal Institute of Medical Science & Technology (SCTIMST), Trivandrum |
56 |
2252 |
40.21 |
19 |
16 |
28.57 |
2.11 |
Top 10 Most Impactful organizations |
||||||||
1 |
Sri Ramachandra Institute of Higher Education & Research (SRIHER), Madras |
21 |
6988 |
332.8 |
9 |
8 |
38.1 |
17.4 |
2 |
Christian Medical College (CMC), Vellore |
17 |
3355 |
197.4 |
9 |
7 |
41.18 |
10.3 |
3 |
Institute of Genome & Integrated Biology (IGIB), Delhi |
20 |
3525 |
176.3 |
13 |
8 |
40 |
9.24 |
4 |
King George’s Medical University (KGMU), Lucknow |
48 |
5321 |
110.9 |
16 |
15 |
31.25 |
5.81 |
5 |
Sanjay Gandhi Postgraduate Institute of Medical Sciences (SGPGIMS), Lucknow |
35 |
3763 |
107.5 |
13 |
5 |
14.29 |
5.63 |
6 |
Postgraduate Institute of Medical Education & Research (PGIMER), Chandiagrh |
75 |
7597 |
101.3 |
16 |
12 |
16 |
5.31 |
7 |
Panjab University, Chandigarh |
57 |
4881 |
85.63 |
19 |
6 |
10.53 |
4.49 |
8 |
University of Delhi |
56 |
3951 |
70.55 |
19 |
16 |
28.57 |
3.7 |
9 |
Indian Instiyute of Toxicologi, Lucknowcal Research (IITR) |
101 |
5903 |
58.45 |
31 |
17 |
16.83 |
3.06 |
10 |
All India Institute of Medical Sciences (AIIMS), New Delhi |
162 |
9032 |
55.75 |
26 |
24 |
14.81 |
2.92 |
Table 5: Top 10 Most Productive/Cited Organizations in Parkinson’s Disease Research during 1982-2019.
Note: *TP-Total publications; TC -Total citations; CPP-Citations per paper; ICP-International collaborative papers; RCI-Relative citation index
Institutional Collaboration among Top 15 Indian Organizations: On studying collaborative linkages among top 15 organizations, it was noticed that organizations having highest number of linkages were: IITR-Lucknow, AIIMS-New Delhi and NIMHANS-Bangalore) (51, 35 and 29) and having least linkages were: Annamalia University, AMU –Aligarh and CFTRI – Mysore (3, 3 and 1). Across top 15 organizations, the largest number of collaborative linkages (16) is between AIIMS - New Delhi and University of Delhi, followed by IITR-Lucknow and BHU – Varanasi (14 linkages), IITR-Lucknow and KGMU – Lucknow (11 linkages), NIMHANS - Bangalore - AIIMS - New Delhi (9 linkages), etc (Figure 7).
Figure 7: Collaborative Network of Top 15 Organizations in Parkinson’s disease Research during 1990-2019.
Top 10 most productive & cited authors
The scientometric profile of top 10 most productive and top 10 most cited authors are presented in Table 6. In all, 871 authors from India participated in Parkinson’s disease research during 1990-2019. The top 50 authors contributed a 36.042% share to the total country output in the subject. Their research productivity varied from 13 to 79 publications per author.
S.No |
Name of the Author |
Affiliation of the Author |
TP |
TC |
CPP |
HI |
ICP |
ICP (%) |
RCI |
Top 10 Most Productive Authors |
|||||||||
1 |
P.K. Pal |
NIMHANS-Bangalore |
79 |
833 |
10.54 |
17 |
10 |
12.66 |
0.55 |
2 |
M.Behari |
AIIMS – New Delhi |
73 |
1587 |
21.74 |
20 |
7 |
9.59 |
1.14 |
3 |
K.P.Mohanakumar |
IICB-Kolkata |
56 |
1857 |
33.16 |
24 |
18 |
32.14 |
1.74 |
4 |
V.Goyal |
AIIMS – New Delhi |
42 |
317 |
7.55 |
10 |
5 |
11.90 |
0.40 |
5 |
T.Manivasagam |
Annamalai University |
41 |
959 |
23.39 |
20 |
29 |
70.73 |
1.23 |
6 |
M.P.Singh |
IITR-Lucknow |
41 |
974 |
23.76 |
21 |
2 |
4.88 |
1.25 |
7 |
R.Yadav |
NIMHANS-Bangalore |
39 |
278 |
7.13 |
9 |
2 |
5.13 |
0.37 |
8 |
A.Kishore |
SCTIMST-Trivandrum |
33 |
836 |
25.33 |
16 |
13 |
39.39 |
1.33 |
9 |
U.B.Muthana |
NIMHANS-Bangalore |
33 |
645 |
19.55 |
16 |
10 |
30.30 |
1.02 |
10 |
A.Borah |
Assam University |
30 |
578 |
19.27 |
14 |
7 |
23.33 |
1.01 |
Top 10 Most Impactful Authors |
|||||||||
1 |
R.B.Mythri |
NIMHANS-Bangalore |
13 |
762 |
58.62 |
11 |
5 |
38.46 |
3.07 |
2 |
R.K.Chaturvedi |
IITR-Lucknow |
19 |
1041 |
54.79 |
15 |
4 |
21.05 |
2.87 |
3 |
K.S.Saravanan |
IICB-Kolkata |
13 |
639 |
49.15 |
11 |
4 |
30.77 |
2.58 |
4 |
A.K.Agrawal |
IITR-Lucknow |
13 |
526 |
40.46 |
11 |
4 |
30.77 |
2.12 |
5 |
V.Ravindranath |
NBRI-Gurgaon |
17 |
677 |
39.82 |
13 |
3 |
17.65 |
2.09 |
6 |
S.K.Shankar |
NIMHANS-Bangalore |
13 |
488 |
37.54 |
9 |
4 |
30.77 |
1.97 |
7 |
J. Ali |
JamiaHamdard-Delhi |
22 |
824 |
37.45 |
14 |
10 |
45.45 |
1.96 |
8 |
S.Baboota |
JamiaHamdard-Delhi |
22 |
824 |
37.45 |
14 |
10 |
45.45 |
1.96 |
9 |
S.Chakrabarti |
IPGMER-Kolkata |
13 |
437 |
33.62 |
10 |
6 |
46.15 |
1.76 |
10 |
K.P.Mohanakumar |
IICB-Kolkata |
56 |
1857 |
33.16 |
24 |
18 |
32.14 |
1.74 |
Table 6: Publication Profile of Top 10 Indian Most Productive and 10 Most Impactful Authors in Parkinson’s disease Research during 1990-2019.
Note: *TP-Total publications; TC -Total citations; CPP-Citations per paper; ICP-International collaborative papers; RCI-Relative citation index
Collaboration among top 15 authors: On studying collaborative linkages among top 15 authors, it was noticed that authors having highest linkages were: P.K. Paul, A. Lenka, M.Behari and V.Goyal (62, 40, 39 and 27) and having least linkages were: A.Kishore, T.Manivasagam and K.P. Mohanakuma (1, 4 and 8). Across top 15 authors, the largest number of collaborative linkages (33) is between P.K. Paul – R.Yadav, P.K.Paul – A.Lenka (26), M.Behari and V.Goyal (23) and J.Ali and S.Baboota (22), R.Yadav and A. Lenka (14), M.Behari and U.B.Muthana (11), etc. (Table 7, Figure 8).
S.No |
Name of the Journal |
Number of Papers (TP) |
TC |
CPP |
||
1982-00 |
2001-19 |
1982-19 |
1982-19 |
|||
Top 10 Most Productive Journals |
||||||
1 |
Neurology India |
30 |
87 |
117 |
838 |
7.16 |
2 |
Annals of the Indian Academy of Neurology |
0 |
64 |
64 |
260 |
4.06 |
3 |
Parkinsonism & Related Disorders |
4 |
56 |
60 |
1043 |
17.38 |
4 |
Molecular Neurobiology |
0 |
40 |
40 |
560 |
14.00 |
5 |
CNS aand Neurological Disorders Drug Targets |
0 |
39 |
39 |
560 |
14.36 |
6 |
Movement Disorders |
10 |
28 |
38 |
1337 |
35.18 |
7 |
Journal of the Neurological Sciences |
5 |
26 |
31 |
622 |
20.06 |
8 |
Neurochemical Research |
0 |
30 |
30 |
698 |
23.27 |
9 |
Asian Journal of Pharmacological & Clinical Research |
0 |
29 |
29 |
127 |
4.38 |
10 |
Neurochemistry International |
1 |
28 |
29 |
649 |
22.38 |
Top 10 Most Impactful Journals |
||||||
1 |
Brain Research |
5 |
18 |
23 |
1190 |
51.74 |
2 |
Movement Disorders |
10 |
28 |
38 |
1337 |
35.18 |
3 |
Current Pharmaceutical Design |
0 |
18 |
18 |
463 |
25.72 |
4 |
Neurochemical Research |
0 |
30 |
30 |
698 |
23.27 |
5 |
Neurochemistry International |
1 |
28 |
29 |
649 |
22.38 |
6 |
Journal of the Neurological Sciences |
5 |
26 |
31 |
622 |
20.06 |
7 |
PLOS One |
0 |
18 |
18 |
325 |
18.06 |
8 |
Parkinsonism & Related Disorders |
4 |
56 |
60 |
1043 |
17.38 |
9 |
Neurotoxicity Research |
2 |
22 |
24 |
409 |
17.04 |
10 |
Neuroscience Letters |
3 |
26 |
29 |
491 |
16.93 |
Table 7: Most Productive Journals in which India Published Parkinson’s disease research 1990-2019.
Figure 8: Collaborative Network of Top 15 Authors in Parkinson’s disease Research during 1990-2019.
Medium of research communication
The bulk of publications output by India in Parkinson’s disease research (92.44%, 2911) appeared in journals, and the remaining appeared in conference proceedings, book series and books (3.81%, 2.29% and 1.46%). Of the 563 journals partcipitated in India’s Parkinson’s disease output: 460 published 1-5 papers each, 60 published 6-10 papers each, 22 published 11-20 papers each, 18 published 21-50 papers each, 2 each published 51-100 papers each and 1 published 117 papers during 1990-2019.
The top 50 most productive journals published 15 to 117 papers and together they account for a 30.47% (887) share of total output by India in Parkinson’s disease research output during 1990-2019. The most productive journals in the subject are Neurology India (117 papers), Annals of the Indian Academy of Neurology (64 papers), Parkinsonism & Related Disorders (60 papers) and Molecular Neurobiology (40 papers).The Brain Researchjournal tops on citations per item 51.74, followed by Movement Disorders (35.18), Current Pharmaceutical Design (25.72) and Neurochemical Research (23.27), during 1990-2019. Top 10 most productive and most impactful journals are listed in Table 7.
Highly-cited papers
Only 84 (2.67% share) out of 3149 publications in Parkinson’s disease registered 100 to 3730 citations per paper and together received 23435 citations, with an average of 278.99 citations per paper. Among 84 highly-cited papers by citations count: 62 had registered citations in the range 100-199 per paper, 9 were in the citation range 200-299, 3 the in citation range 300-399, 5 in the citation range 400-699, 4 in the citation range 1001-1673 and 1 with 3730 citations.
Of the 84 highly-cited papers (43 articles, 40 reviews and 1 editorial), 42 were non-collaborative among rest: 8 and 34 were national and international collaborative papers.Among the India’s 34 international collaborative papers, USA participated in 25 papers, followed by Italy , Japan (11 papers) and UK (10-12 papers), Australia, Canada, Germany, Spain, Singapore and the Netherlands (9 papers each), A
This paper seeks to examine the status of Parkinson’s disease research in India in the global context covering publications for the period 1990-2019. India registered a faster 22% annual research growth compared to 7.06% by the world in the subject. Its research growth was comparatively faster in the 2nd half of the study period (2005-2019) compared to its 1st half (1990-2004). However, despite its faster research growth, India is weak in terms research productivity and far behind compared to the top most productive countries in the world, such as the USA, the UK, and Germany. Currently, India ranks as the 13th most productive country in the world accounting for as little share to the world as 2.35%. The low-level research productivity in India may be attributed to poor research productivity at the institutional level. For instance, top 50 institutes in India had merely contributed 16-210 papers, an average of average 39.64 papers per institute in the 30-year period. It seems that research in the domain of Parkinson’s disease is still not a priority research area in the country. The other probable reason for low-level research productivity could be lack of project funding options Parkinson’s disease research.
India published 21.88% of its output as a share of international collaborative papers. The citation impact of such collaborative papers has been nearly twice (35.19 CPP) that of the country average (19.08 CPP). The USA was its single largest collaborating partner in international research projects, followed by the U.K. and Germany. The data here indicates that India should pursue more and more international collaborative projects in order to improve the visibility and impact of its research in the domain Parkinson’s disease research at international level.
Further, a close study of the citation life cycle of top 10 most cited papers reveals the citation peak period for the most recent papers published between 2015-17 is three-four years, whereas for the other papers published between 2003-10, it is 10-14 years. This implies that the quality and impact of recent research in the subject is far more impressive and visible, getting far more national and international attention than the other research papers in the subject. The data here highlights the view that has talent in the domain of Parkinson’s disease research and such a talent must be nurtured.
The pockets of excellence in Parkinson’s disease research are centered around top 10 institutes - Panjab University, Chandigarh, All India Institute of Medical Sciences (AIIMS), New Delhi, Central Drug Research Institute (CDRI), Lucknow, Postgraduate Institute of Medical Education & Research (PGIMER), Chandiagrh, Indian Instiyute of Toxicologi, Lucknowcal Research (IITR), National Institute of Mental Health & Neurosciences (NIMHANS), Bangalore, SreeChitraTirunal Institute of Medical Science & Technology (SCTIMST), Trivandrum, Indian Institute of Chemical Biology (IICB), Kolkata, JamiaHamdard University, Delh, and Annamalia University. Their research output as a share of international collaborative papers ranged between 10.53% and 50.82%.
The global research in the domain of Parkinson’s disease is dominated by top 15 most productive countries as they account for 99.59% share of the world output. India ranks as the 13th largest most productive country in the world. India is very weak in terms of research productivity. But its performance in terms of citation impact is moderately high. Further, the study observes that weak research productivity by India in the domain Parkinson’s disease may due to lack of adequate research project funding or due to the fact that Parkinson’s disease research is not a top priority area of the country. Given the fact, the potential to improve research productivity and impact in the subject is great, it is important that stakeholders at national and state level in the country should draw up plans to support, advance, and encourage in-house as well as collaborative national and international research in the domain of Parkinson’s disease research.
Citation: Gupta BM, Dhawan SM (2021) Parkinson’s Disease Research by India: A Scientometric Assessment of Publications Output for the Period 1990-2019. J Brain Neursci 5: 017.
Copyright: © 2021 Gupta BM, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.