Cohort profile: the BangladEsh Longitudinal Investigation of Emerging Vascular and nonvascular Events (BELIEVE) cohort study
Authors: Chowdhury Rajiv , Khan Nusrat , Pennells Lisa , Iurilli Maria L C , Uddin Miah Md Taslim , Monower Md Mostafa , Rahman Khan Mohammad Thouhidur , Samin Sharraf , Saqeeb Kazi Nazmus , Tasmin Ishrat , Farrow Eleanor , Farrow Samantha , Michielsen Ank , Perry Catherine , Spackman Sarah , van Coeverden Charlotte , Walker Matthew , Ahmed Tahmeed , Ajioka James , Awal Khondker Abdul Abdul , Butterworth Adam S , Chatzidiakou Evangelia , Feldmann Jörg , Fenner Richard , Flora Meerjady Sabrina , Haque Tuhin , Hawkes Sarah , Islam Syed Shariful , Islam Sirajul , Jones Roderic L , Kaptoge Stephen , Khan Kamrul Hasan , King Lawrence , Luhar Shammi , Malik Abdul , Malik Fazila-Tun-Nesa , Naved Ruchira T , Naheed Aliya , Popoola Olalekan , Raqib Rubhana , Shirin Tahmina , Sutton Stephen , van Daalen Kim Robin , Wood Angela , Griffin Simon , Mascie Taylor Nicholas , Khalequzzaman Md , Khan Md Alfazal , Choudhury Sohel Reza , Di Angelantonio Emanuele , Danesh John 
Published: January 2025

PurposeBangladesh has experienced a rapid epidemiological transition from communicable to non-communicable diseases (NCDs) in recent decades. There is, however, limited evidence about multidimensional determinants of NCDs in this population. The BangladEsh Longitudinal Investigation of Emerging Vascular and nonvascular Events (BELIEVE) study is a household-based prospective cohort study established to investigate biological, behavioural, environmental and broader determinants of NCDs.ParticipantsBetween January 2016 and March 2020, 73 883 participants (aged 11 years or older) were recruited from 30 817 households across urban, urban-poor (‘slum’) and rural settings in Bangladesh. A structured questionnaire was administered by trained personnel recording participants’ demographic, socioeconomic, behavioural, medical, environmental and other factors. Anthropometric measurements and blood pressure were recorded for each participant. Biological specimens were collected and aliquoted for long-term storage and analysis.Findings to dateOf the 73 883 study participants (mean [SD] baseline age: 39 [15] years), 43 470 (59%) were females, and 38 848 (52%) had no or only primary-level education. Focusing only on the 65 822 adult participants aged 20–79 years at baseline, 15 411 (23%) reported being diagnosed with hypertension; 10 578 (16%) with type 2 diabetes and 7624 (12%) with hypercholesterolaemia. Age and sex-standardised prevalences of these conditions were much higher in urban than slum and rural settings. Overall, the mean (SD) body mass index (BMI) was 25 (5) kg/m2, with 10 442 (16%) participants aged 20–79, classified as obese (ie, BMI≥30 kg/m2). Mean BMI was also higher in urban than slum and rural areas.Future plansThe collection of information during the baseline visit was completed in 2020. Regular longitudinal follow-up is ongoing for ascertainment and adjudication of a range of fatal and non-fatal health outcomes among participants. This cohort will provide a powerful resource to investigate multidimensional determinants of incident NCDs across diverse settings in Bangladesh, helping to advance scientific discovery and public health action in an archetypal low-middle-income country with pressing public health needs.