Data

A variety of administrative and statistical data are linked in the NILS. Most of the data come from the 2001 Census, General Register Office (GRO) vital events and demographic data derived from health registrations.

The data collected relates to NILS members.  For each NILS member having a link to the 2001 Census, additional information is collected for each non-NILS member living in the same household.  Vital events data and migration events are only linked to the NILS sample members and not the non-NILS household members.  Migration events are taken from six monthly downloads from health registration data in which activity relating to changes in address information are recorded. For many research studies the sample members are of most interest, however, with the inclusion of variables describing those living in the same household, the research scope of the study may be enhanced. 

NILS members are selected based on their annual birth date (day and month).  104 dates throughout the calendar year were selected (100 unique to Northern Ireland and the 4 England and Wales LS dates).  If someone has a date of birth coinciding with one of the 104 NILS dates, then they are included in the study.

The Datasets include:

1. 2001 Census data for NILS members including data on:

Note: Please click on the following link for a copy of the 2001 Census form.

• Age, sex and marital status
• Family, household or communal establishment type
• Housing, including tenure, rooms and amenities
• Country of birth
• Ethnicity
• Educational qualifications
• Economic activity
• Occupation and social class
• Migration
• Long-standing illness
• Self-rated health
• Religion
• Care giving

2. 2001 Census data for those living in the same household as a NILS member

This includes similar information as collected for the NILS members (listed above).

3. Vital Events (GRO Data)

• New births into the sample
• Births to sample mothers
• Births to sample fathers
• Stillbirths to sample mothers
• Stillbirths to sample fathers
• Infant mortality of children of sample mothers
• Infant mortality of children of sample fathers
• Deaths of sample members

4. Migration Events (Health Card Data)

• Immigrants into the sample
• Emigration out of Northern Ireland of sample members
• Re-entries into Northern Ireland after previous emigrations of sample members
• Migration within Northern Ireland of sample members

Other Data

5. Valuations and Lands Agency (VLA) Data

The VLA are responsible for rating assessments in Northern Ireland and hold a database of all properties with associated household characteristics such as number of rooms, property type, floor space, central heating etc.  This information is linked to the households of the NILS members.  Also included are the capital values of each property. These are taken from the recent Northern Ireland Rating Reform which used house values as at 1 January 2005 to calculate new rate charges.