A priori factors considered for inclusion in the analysis
| Population factors | |
| Age | |
| Age stratification | Six age groups (0–19, 20–44, 45–54, 55–64, 65–74 and 75+). Age stratification was constrained by the age-specific level of the other independent factors included. |
| Deprivation | |
| Unemployment37 | 2016: percentage of population unemployed. |
| SILC deprivation38 | 2014, 2015, 2016: percentage of population deprived. Based on the Survey of Income and Living Conditions (SILC) Deprivation Scale regarding ability to buy certain goods and services. |
| HP deprivation39 | 2016: percentage of population with greater than average levels of deprivation. Based on the Pobal HP Deprivation Index. |
| SAHRU deprivation40 | 2011: percentage of population living in electoral districts in the lowest quintile of deprivation. Based on the Small Area Health Research Unit (SAHRU) Deprivation Index. |
| Geography | |
| Rurality68 | 2016: percentage of the population living in rural areas. Areas with a population below 1500 inhabitants are classified as belonging to the Aggregate Rural Area.69 |
| Health system factors | |
| Hospital | |
| Conversion rate3 70 | 2014, 2015, 2016: conversion rate of all emergency presentations to emergency admissions by hospital, weighted by the probability of a person from each county being admitted to that hospital. |
| LOS of 1 day3 | 2014, 2015, 2016: percentage of all emergency admissions with a length of stay (LOS) of 1 day, by county of residence. |
| Primary care | |
| GPs71 | 2011: number of general practitioners (GPs) per 100 000 population. |
| Financial factors/funding of healthcare | |
| GMS25 | 2014, 2015, 2016: percentage of the population eligible for the General Medical Services (GMS) card. |
| Private health insurance41 42 | 2015: percentage of the population with private health insurance. |