Northern Ireland Longitudinal Study (NILS)
The NILS is a longitudinal dataset of people of all ages living in Northern Ireland. The dataset links together censuses from 1981, 1991, 2001, and 2011 with administrative data. As of 2024, it is proportionally the largest longitudinal study in the United Kingdom, covering 28% of the Northern Ireland population and accounting for approximately 50% of Northern Ireland households. Follow-up occurs through the linkage of census data, and vital events such as births and deaths are updated regularly from routine registration data.
Study design
Cohort
Number of participants at first data collection
508,000 (participants)
Age at first data collection
Varied (participants)
Participant year of birth
Varied (participants)
Participant sex
All
Representative sample at baseline?
The Northern Irish population.
Sample features
Countries
Year of first data collection
1981 (linked Census data)
2006 (NILS baseline)
Primary Institutions
Queen's University of Belfast (QUB)
Profile paper DOI
Funders
Economic and Social Research Council (ESRC)
Northern Ireland Statistics and Research Agency (NISRA)
Public Health Agency (PHA)
Ongoing?
Yes
Data types collected
- Secondary data
- None
- None
- Census data
- Geographic, spatial & environmental data
- Medical birth registry
- Mortality data
- Other government data
Engagement
Keywords
