Cohort Profile: Indian Study of Healthy Ageing (ISHA-Barshi)

Why was the cohort set up?The Indian Study of Healthy Ageing (ISHA) is a blood-based prospective cohort study of approximately 220 000 individuals aged 30-69, recruited between 2015 and 2020 from towns and villages around Barshi, Solapur district, Maharashtra state, India (Supplementary Figure S1, available as Supplementary data at IJE online).The study was established with the aim of testing hypotheses relating to lifestyle, diet, obesity and related factors, and of identifying potential genetic determinants of cancer and other chronic diseases in a general population with low baseline risk.Table 1 shows 2019 age-standardized mortality rates for middle-aged men and women in Barshi, India, the USA and the UK.All-cause mortality was notably higher in Barshi than in the USA and UK, but was moderately lower than India's national mortality rates, particularly among women.Vascular disease accounted for about one-third of premature adult mortality in Barshi, and ischaemic heart disease accounted for a substantially higher proportion in Barshi than in the UK and USA.There were also notably higher respiratory disease mortality rates in Barshi, although rates were lower than in India overall among both men and women.Previous studies in India have reported similar patterns of vascular disease, 1 but much remains unknown about factors underlying these Key Features� The Indian Study of Healthy Ageing (ISHA) examines the burden, causes and consequences of chronic diseases in an Indian adult population of �220 000.Once completed, ISHA will be the largest blood-based prospective study in South Asia.Expansion to sites in Varanasi, Guwahati, Sangrur and Mullanpur will further strengthen the study.� Recruitment began in 2015 in Barshi, Maharashtra state, India.Enumeration, including basic baseline data collection, has been completed for all participants.Further detailed data collection, through questionnaires, physical measurements and blood sampling, is complete for �39 000 participants and ongoing.Active follow-up and linkage to health-related datasets (for death, cancer and hospitalization) provide data on fatal and non-fatal disease events.� At baseline among the �39 000 participants, 53% were women, and mean (standard deviation: SD) age was 46 (11).Tobacco smoking and alcohol drinking are relatively uncommon, but tobacco chewing is prevalent (67% of men and 14% of women ever chewed tobacco).The population is relatively lean, with a mean (SD) body mass index of 23.2 (4.1) kg/m 2 .Self-reported, previously diagnosed chronic diseases were uncommon (hypertension: 6%; diabetes: 3%; cardiovascular disease: 1%; cancer: <1%).Depressive symptoms were common (at least one reported by 58%).� Data-sharing regulations are in place; specific proposals for future collaboration are welcomed.