ESRI Hippocrates Model Research Note 1

Introduction

A key input to any process that estimates future health and social care service utilisation for planning purposes is population projections. Understanding how the population may change both in terms of size and structure is essential for producing accurate projections. In Ireland, such projections are routinely produced at national and county level by the Central Statistics Office (CSO) and the Economic and Social Research Institute (ESRI). However, the introduction of new regional health geographies (HSE Health Regions), which are not coterminous with county boundaries, creates a challenge for producing regional-level population projections for health service planning.

In 2025, the ESRI undertook a body of work projecting demand and capacity requirements to 2040 for the health and social care system at the national and HSE Health Region level (Brick and Kakoulidou, 2025; Brick et al., 2025; Connolly et al., 2025a; b; Walsh and Kakoulidou, 2025a; b), Projections at the HSE Health Region level (Figure 1) required estimates of both base year population and projected population for each region to 2040. In the absence of officially published population data or projections for the new HSE Health Regions, this research note provides detail on how mapped population estimates benchmarked to Census 2022 were developed to support health service planning and analysis. The workbook accompanying this note provides population estimates for 2022 and projected populations for 2040, disaggregated by five‑year age groups, sex, and HSE Health Region.