The search strategy advocated by Gasparyan et al. (11) was adhered to. To infer data regarding epidemiology of rheumatologic diseases in India, we searched the MEDLINE and Scopus databases using the search terms "epidemiology", "Rheumatic", "India" AND "COPCORD". Additional references were derived from searches on the COPCORD section of the website of the APLAR. Data regarding training programs in rheumatology and clinical immunology in India was derived from searches on the Medical Council of India (MCI) website and the websites of tertiary care centers of national importance (which conduct their own courses outside the purview of the MCI).

The first studies to identify rheumatic diseases at a community level emanated from a suburban area near New Delhi in the early 1990s. Under the stewardship of Professor AN Malaviya, the prevalence of musculoskeletal complaints in general, rheumatoid arthritis, spondyloarthropathy (12) and SLE (13) were studied. The first study identified a prevalence of 8.5% for musculoskeletal complaints, amongst more than 44,000 people studied. The most common cause was related to non-specific musculoskeletal complaints (2.07%), followed by osteoarthritis (1.89%). With regards to inflammatory rheumatic diseases, 0.75% had rheumatoid arthritis and 0.36% seronegative spondyloarthropathy (12). The second study screened over 52,000 people for lupus (using both clinical criteria and antinuclear antibodies) and projected a population prevalence of 3 per 100,000 (13).

Further community-based studies on the prevalence of rheumatic disorders have been driven by the Community Oriented Programme for Control of Rheumatic Diseases (COPCORD), which has been borne out of collaboration between the World Health Organization (WHO) and the International League Against Rheumatism (ILAR) (14). The first COPCORD studies in India were started in a rural population in Western India (The Bhigwan Cohort) under the stewardship of Chopra et al. (15) and later expanded to include rural areas in Kerala (16) and subsequently all over the country under the aegis of the Bone and Joint Decade (BJD) (17). These studies provided invaluable information at a community level regarding the burden of musculoskeletal diseases in India. Musculoskeletal pain was prevalent in 6.4%-23.6% of the Indian population (18). The most common causes of impaired quality of life due to musculoskeletal pain were the duration of symptoms, pain in shoulders and hand, and back pain (16). The most prevalent rheumatic problems were non-specific musculoskeletal complaints (4.25%-6.25%), osteoarthritis (4.39%-6.25%, of which knee osteoarthritis comprised 3.34%-4.42%) and soft tissue rheumatism 1.31%-3.77%. Inflammatory rheumatic diseases had a prevalence of less than 1% each (rheumatoid arthritis 0.34%-0.67%, undifferentiated inflammatory arthritis 0.22%-0.76%, spondyloarthritis 0.23%-0.3%, gout 0.04%-0.13% and lupus 0.02%) (17). Interesting data has emerged from the COPCORD initiative at Bhigwan regarding the peculiarity of rheumatic diseases in India. The largest series of musculoskeletal symptoms related to Chikungunya virus infection, comprising 156 patients, has been reported from this center (19). It is also intriguing to note that the commonest type of juvenile idiopathic arthritis (JIA) prevalent in India, as per the ILAR classification criteria (20) is enthesitis-related arthritis, accounting for more than a third of patients with JIA (21), as opposed to the West where enthesitis-related arthritis accounts for only 10% patients with JIA and instead oligoarticular JIA is the commonest variant (22). There is a need for more community-based studies in India to delineate the similarities and differences of various rheumatic diseases in India compared to the rest of the world.

The first exclusive Rheumatology clinic in India was set up at All India Institute of Medical Sciences (AIIMS), New Delhi by Professor AN Malaviya. As per the regulations of the Medical Council of India, sub-specialty training (normally for a period of three years) in rheumatology/clinical immunology is allowed only after completing residency in Medicine or Pediatrics. The first training program (which goes by the name of Doctor of Medicine or DM) in Clinical Immunology was started by Sanjay Gandhi Postgraduate Institute of Medical Sciences (SGPGIMS), Lucknow. This was followed by the DM program in Rheumatology at Madras Medical College (MMC), Chennai. In 2005, there were less than 5 DM seats in India for Rheumatology or Clinical Immunology training. As of today, 22 fellows are trained every year in DM courses run at 8 different institutions in the country [DM Rheumatology: 12, MMC – 4, Nizam's Institute of Medical Sciences (NIMS), Hyderabad – 3, King George Medical University (KGMU), Lucknow – 2, Institute of Postgraduate Medical Education and Research (IPGMER), Kolkata – 2, Christian Medical College (CMC), Vellore – 1); DM Clinical Immunology: 6, SGPGIMS – 4, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry – 2; DM Rheumatology and Clinical Immunology: Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh – 3; DM Pediatric Rheumatology and Clinical Immunology: PGIMER – 1] (232425). Separate training for Pediatric Rheumatology exists only in one center i.e. PGIMER, Chandigarh. Also, the National Board of Medical Examinations offers the degree of Diplomate of the National Board (DNB) in Rheumatology (4 per year). A significant proportion of specialists catering to patients with rheumatic diseases have been trained abroad. In a country with a population exceeding 1.2 billion, training 26 doctors in Rheumatology every year is grossly inadequate to cater to the ever-expanding population. There is an urgent need to train more doctors in the specialty to cater to the needs of the population. Considering that 2,368 doctors complete residency in Internal Medicine and 1,209 doctors complete residency in Pediatrics every year, training 26 fellows in the sub-specialty of Rheumatology every year is grossly inadequate (especially when compared to other sub-specialties – e.g. 282 fellows in Cardiology and 175 fellows in Neurology every year) (23). Given the immense need for trained persons to cater to the enormous burden of rheumatologic disorders in India, it is essential to have a rheumatology or clinical immunology department/unit in every medical college (government or private) in the country.

Fig. 1 summarizes the search strategy used (11). Data regarding publications from India in rheumatic diseases was derived from searches on the Scopus database (which also includes all the data from MEDLINE) by searching the article title, abstracts and keywords using the following search words: "rheumatoid arthritis", "spondyloarthritis", "ankylosing spondylitis", "reactive arthritis", "psoriatic arthritis", "enteropathic arthritis", "lupus", "systemic lupus erythematosus", "SLE", "Sjogren", Sjogren's syndrome", "vasculitis", "Takayasu", "Kawasaki", "ANCA", "dermatomyositis", "polymyositis", "inclusion body myositis", "idiopathic inflammatory myositis", "osteoarthritis", "osteoporosis", "systemic sclerosis", "scleroderma", "mixed connective tissue disease", "MCTD", "juvenile idiopathic arthritis", "enthesitis related arthritis", "oligoarticular JIA", "polyarticular JIA", "infective arthritis", "chikungunya arthritis", "tuberculous arthritis", "leprosy arthritis", "fibromyalgia", "complementary and alternative medicines", "ayurveda", "siddha", "homeopathy", "unani". Searches were limited from 01 January 2010 to 22 October 2015 to include recent publications. These publications were analyzed with respect to number of publications, number of citations, h-index, year of publication, type of article, institutions with highest number of published papers and collaborative efforts, both worldwide and regional.

Table 1 summarizes the number of publications and citations in different rheumatic diseases. The h-index (26) (named after Jorge Hirsch, the scientist who proposed this metric) is a measure of the citability of an author, journal or group of articles. An h-index of n implies that, for a particular author, journal or group of articles, n articles have been cited at least n number of times in databases such as Google Scholar and Web of Science. Our search revealed that overall, rheumatoid arthritis, systemic lupus erythematosus and osteoporosis were the three areas with the highest number of publications, and also comprised the highest numbers of citations. The h-index was highest for rheumatoid arthritis (29), followed by osteoporosis (26), systemic lupus erythematosus and osteoporosis (23 each). Table 2 summarizes the number of publications in each of the years from 2010 to 2015. The number of publications remained similar in each year across different diseases. Table 3 summarizes the types of publications. Articles (original or case reports) comprised 51%-80%, review articles 10%-29%, book chapters 0%-10% and editorials 0%-4% each in the different subject areas.

India is a vast country with different ethnic backgrounds in different areas. For this reason (using the same strategy and search of Scopus and MEDLINE database as described above), we chose to analyze data regarding publishing activities of institutions by dividing India into Eastern India (Bihar, West Bengal, Odisha, North-Eastern states), Western India (Maharashtra, Goa, Gujarat and Rajasthan), North and Central India (Madhya Pradesh, Chattisgarh, Delhi, Uttarakhand, Haryana, Punjab, Jammu and Kashmir) and South India (Andhra Pradesh, Karnataka, Tamil Nadu, Kerala and Puducherry). Overall, the institution with most publications across specialties for the whole country as well as for North and Central India was Postgraduate Institute of Medical Education and Research, Chandigarh. The most published institutions from other parts of India were Christian Medical College, Vellore from South India, Institute of Postgraduate Medical Education and Research, Kolkata from Eastern India and King Edward Medical College, Mumbai from Western India.

Table 4 summarizes research publications culminating from collaborative research with Indian rheumatologists. Worldwide, the top three collaborating nations were the United States of America, the United Kingdom and France. From Asia, the top three collaborators were Japan, Saudi Arabia and Singapore. Collaborations between Korean and Indian scientists resulting in published papers were mostly in the subject areas of rheumatoid arthritis, osteoarthritis and osteoporosis. We could not find any retractions from India in the field of Rheumatology.