Challenges in estimating the burden of neurological disorders across Indian states
Authors: Rajinder K Dhamija, Alvee Saluja
Journal: The Lancet Global Health (2021)

We read with great interest the study by the India State-Level Disease Burden Initiative Neurological Disorders Collaborators, published in The Lancet Global Health.1India State-Level Disease Burden Initiative Neurological Disorders CollaboratorsThe burden of neurological disorders across the states of India: the Global Burden of Disease Study 1990–2019.Lancet Glob Health. 2021; 9: e1129-e1144Summary Full Text Full Text PDF PubMed Scopus (11) Google Scholar The study, as part of the Global Burden of Diseases, Injuries, and Risk Factors Study 2019, aimed to estimate the burden of various neurological disorders across Indian states from 1990 to 2019. Although the study had a sound methodology, we think a number of questions need to be addressed, in particular regarding the mortality estimates. The study used the Indian Sample Registration System (SRS) cause of death data and Medical Certification Cause of Death (MCCD) data to estimate mortality. However, these systems might not give reliable estimates of the actual number of deaths. The SRS is a demographic survey that covers only 0·6% of the national population. Furthermore, mortality data in the SRS are collected by community-based workers with semiannual checks by medical supervisors. A 2020 study also found that the SRS grossly underestimates mortality in the 30–69 years age group, which is the core age group for neurological disorders.2Rao C Gupta M The civil registration system is a potentially viable data source for reliable subnational mortality measurement in India.BMJ Glob Health. 2020; 5: e002586Crossref PubMed Scopus (11) Google Scholar That study showed that the Civil Registration System (CRS) in India is a much more reliable estimator of mortality, particularly at the subnational level in the 30–69 years age group. Although the CRS also shows marked heterogeneity in reporting of deaths across states (particularly in rural areas and among women and children), the coverage has steadily improved during the past 10 years, with 92·0% of estimated deaths being registered in the CRS in 2019 at the national level.3Office of the Registrar General of IndiaVital statistics of India based on the Civil Registration System 2019. Ministry of Home Affairs, Vital Statistics Division, New Delhi2021https://crsorgi.gov.in/web/uploads/download/CRS%202019%20report.pdfGoogle Scholar We acknowledge the fact that the authors have tried to ensure improved accuracy in reporting mortality estimates by including medically certified deaths. However, as per the official reports for 2019, only 20·7% of total registered deaths in India were medically certified.4Office of the Registrar General of IndiaReport on Medical Certification of Cause of Death 2019. Ministry of Home Affairs, Vital Statistics Division, New Delhi2021https://censusindia.gov.in/2011-Documents/mccd_Report1/MCCD_Report_2019.pdfDate accessed: August 7, 2021Google Scholar MCCD data in India are also skewed towards urban areas due to these areas having better health-care facilities than rural areas.4Office of the Registrar General of IndiaReport on Medical Certification of Cause of Death 2019. Ministry of Home Affairs, Vital Statistics Division, New Delhi2021https://censusindia.gov.in/2011-Documents/mccd_Report1/MCCD_Report_2019.pdfDate accessed: August 7, 2021Google Scholar Thus, the MCCD system is also limited by its overall coverage, which might result in underestimation of mortality. Additionally, the authors used cause of death ensemble modelling, a model for data correction and redistribution, and a so-called CoD Correct process for rescaling. However, these are mathematical models which give estimates based on the inputs provided and might not reflect the on-the-ground realities. The study, although well conducted, has these factual limitations. Realistic estimation of the burden posed by neurological disorders in a country such as India with a huge population, heterogenous health-care service and delivery across rural and urban areas, and social constraints (eg, poverty, illiteracy, low educational attainment among women) requires the existing mortality data systems to be strengthened. We declare no competing interests. Challenges in estimating the burden of neurological disorders across Indian states – Authors' replyAs we have noted previously, there are limitations in the cause of death data sources available in India.1 The Medical Certification of Cause of Death (MCCD) data reporting system in the Civil Registration System (CRS) covered less than 20% of the total estimated deaths in India in 2019.2,3 In the absence of an adequate MCCD system in India, the nationwide verbal autopsy data from the Sample Registration System (SRS), which includes 4961 rural and 3886 urban clusters covering about 8 million people, provides a representative sample. Full-Text PDF Open AccessThe burden of neurological disorders across the states of India: the Global Burden of Disease Study 1990–2019The increasing contribution of non-communicable and injury-related neurological disorders to the overall disease burden in India, and the substantial state-level variation in the burden of many neurological disorders highlight the need for state-specific health system responses to address the gaps in neurology services related to awareness, early identification, treatment, and rehabilitation. Full-Text PDF Open Access