Cohort Profile: The Early Childhood Longitudinal Survey (ELPI), Chile

Why was the cohort set up?Chile is often considered a success story in Latin America due to its steady economic growth, strong institutions, and the significant reduction of poverty over recent decades (see Table 1 for key country indicators) [1].According to United Nations Development Program analyses, the national poverty rate dropped markedly between the 1990s and 2022, and access to education, healthcare, and social services has expanded [2].Despite these advances, Chile remains among the most unequal societies in the region, with persistent gaps in wealth distribution, housing conditions, and educational opportunities [3].Multiple studies underscore that large portions of the population face precarious labor markets, limited upward mobility, and stark rural-urban disparities [4].While gross domestic product per capita has increased and extreme poverty has declined, many families still lack consistent access to quality services and face constraints that widen developmental inequities among children [5].Over the past two decades, a few prospective cohort studies have emerged in Chile, mostly following adults or small, regionspecific samples.For example, the Limache birth cohort [6], Key Features• The Early Childhood Longitudinal Survey (Encuesta Longitudinal de Primera Infancia, ELPI) was established to provide the first nationally representative longitudinal evidence on early childhood development in Chile and to document how social, familial, and policy contexts shape developmental inequalities from early life into adolescence.• ELPI is based in Chile and began baseline data collection in 2010.The baseline cohort included 15 175 children born between January 2006 and August 2009, selected using a stratified, two-stage cluster design to ensure national representativeness across urban and rural areas.Children were aged 0-4 years at baseline and represented diverse socioeconomic and geographic backgrounds.• Participants were followed up in 2012, 2017, and 2024.Attrition reached 34.1% by 2024, leaving approximately two-thirds of the original 2010 cohort currently under follow-up.• The study collects extensive data on cognitive, socio-emotional, and physical development; family structure and home environment; parenting practices; caregiver mental health; socioeconomic conditions; childcare and education; and health behaviors.• ELPI data are publicly available through Chile's Banco Integrado de Datos.Researchers can access de-identified datasets and documentation following standard application procedures, enabling national and international collaboration.