Stroke incidence, mortality, subtypes in rural and urban populations in five geographic areas of India

Stroke is one of the leading causes of mortality and disability worldwide and contributes substantially to the burden of non-communicable diseases in India. Reliable population-level estimates of stroke incidence, mortality, and subtype distribution are limited in the Indian context, particularly from rural populations. Most earlier studies were hospital-based and could not accurately estimate the true burden of stroke in the community. To address this gap, the Indian Council of Medical Research–National Centre for Disease Informatics and Research (ICMR–NCDIR) initiated the National Stroke Registry Programme (NSRP) to establish population-based stroke registries across different geographic regions of India. The study aimed to generate standardized and reliable estimates of stroke incidence, mortality, case fatality, and stroke subtypes in urban and rural populations.

The study was a prospective population-based longitudinal surveillance study conducted from January 2018 to December 2019 across five registry areas in India: Cuttack (Odisha), Cachar (Assam), Tirunelveli (Tamil Nadu), Kota (Rajasthan), and Varanasi (Uttar Pradesh). Three registries included both urban and rural populations, while two covered urban populations only.

The study population consisted of adults aged 18 years and above residing in the selected geographic area for at least one year. Only first-ever stroke events were included, while recurrent strokes, transient ischemic attacks (TIA), and non-residents were excluded.

A total of 13,820 stroke cases were registered. The registry followed a complete enumeration approach rather than conventional sampling, aiming to identify all eligible stroke cases occurring in the defined population through multiple overlapping case ascertainment sources.

Data were collected from hospitals, neurology departments, imaging records, intensive care units, physician records, and death registration systems. Standardized case definitions based on WHO criteria were used. Information regarding demographic characteristics, clinical features, stroke subtype, mortality, and residence status was collected using structured data forms.

Statistical analyses included calculation of:

1. Crude incidence rates
2. Age-standardized incidence rates (ASR)
3. Mortality rates
4. Rate ratios by sex and residence
5. Stroke subtype proportions
6. 28-day case fatality proportions

Analyses were stratified by age, sex, and urban/rural residence.

The study reported a pooled crude stroke incidence rate of 138.1 per 100,000 population and an age-standardized incidence rate (ASR) of 103.4 per 100,000 population. Stroke incidence was higher among males compared to females. Ischemic stroke was the most common subtype across all registry regions.

Substantial differences in stroke burden were observed between geographic areas and between rural and urban populations. Rural regions also demonstrated considerable stroke incidence and mortality, highlighting the growing burden of stroke beyond urban settings.

The study found high 28-day case fatality rates, indicating significant mortality following stroke events. Mortality rates were generally higher among males and older age groups.

The registry demonstrated the feasibility of implementing large-scale population-based stroke surveillance systems in India using standardized methodologies.

The study provides important population-based evidence on the burden of stroke in India across multiple geographic regions. The findings indicate that stroke is a major public health problem affecting both urban and rural populations, with ischemic stroke being the predominant subtype. The high incidence and mortality rates emphasize the urgent need for improved stroke prevention, early diagnosis, timely treatment, and rehabilitation services.

The National Stroke Registry Programme establishes an important framework for long-term stroke surveillance in India and can support evidence-based public health planning and policy formulation. Strengthening population-based registries, improving awareness of stroke risk factors, and enhancing access to acute stroke care are essential to reduce the growing burden of stroke in India.