1. The Northern Ireland Longitudinal Study
Mrs Máire Brolly & Dr David Marshall (NISRA - NILS)
Dr Dermot O’Reilly (QUB)

2. NISRA Statistics and Registration for government
to provide high quality demographic information to enable the number and the condition of the population to be monitored and changes over time to be identified
Includes Census and General Register Office (GRO)

3. Content of Presentation
What is the NILS?
What Research can be done?
Future Direction
Management Issues
Dr Dermot O’Reilly

4. What is the NILS? (What is Longitudinal data?)
Longitudinal data trace the experience of the same individuals over time. Can be -
survey-based e.g. Millennium Cohort study
administrative records based – NILS

5. What is the NILS? (Background)
Sample members selected based on birth date
104 birth dates giving 28% sample
500,000 people
Data included
1991 & 2001 Census
Demographic details from GP registrations
Vital Events (births, stillbirths, deaths, marriages)
Migration (derived from GP registration data)

6. What is the NILS? (What types of Analysis?)
Analysis of Census and Event data
Employment status and mortality
Profile population who move
Analysis of Successive Events
Birth spacing
Migration and fertility
Widow(er)hood & Mortality
Simple cross-tabulations or Detailed statistical models

7. What is the NILS? (Example)
27-year old Female in 1991
Address
Change
Address
Change
Marriage
Death
Birth of
Child
Birth of
Child
Census
Census
Census
| | | | | | | | | | | | | | | | | | | | | | |
Single
Employed
Married
Employed
Good General Health
Divorced
Economically Inactive
Poor General Health

8. Births to sample mothers
E&W LS
SLS
NILS
Number Dates 4 20
104
Size
500,000
(1%)
300,000
(5%)
(28%)
Start Date
1971
1991
Number of Censuses 2
Data on
all 3 LSs
Births to sample mothers
Births of sample members
Deaths of sample members
Immigrants
Embarkations

9. Births to Sample Fathers ✔
E&W LS
SLS
NILS
Births to Sample Fathers ✔
Stillbirths/ Infant Deaths
Internal Migration
Cancer Registrations
Hospital Episodes
Education
Marriages
Claimant Count

10. Different People Different issues Different Policies
WHY DOES NI NEED AN LS?
Different People
highest population growth in UK, 2006
highest proportion of children
smallest proportion of pensionable age
highest fertility rate of the 4 UK countries
Different issues
employment rate was the lowest in the UK
highest working age population with no qualifications
house price growth in Northern Ireland breaks all records (in UK)
Different Policies
Northern Ireland Act 1998
Section 75 equality between …
Different People
highest population growth in UK, 2005
highest proportion of children
smallest proportion of pensionable age
highest fertility rate of the 4 UK countries
Different issues
employment rate was the lowest in the UK
highest working age population with no qualifications
house price growth in Northern Ireland breaks all records (in UK)
Different Policies
Northern Ireland Act 1998
Section 75 equality between
Persons of different religious belief
Between persons with a disability and persons without …
Population growth in the year to mid-2005 was fastest in Northern Ireland, at 0.8 per cent.
NI has the largest percentage of children and the smallest percentage of persons of pensionable age:
NI has the highest general and total period fertility rate of the 4 UK countries:
The employment rate (for people of working age) was the lowest in the UK at 68 per cent in spring Northern Ireland has 24% of the working age population with no qualifications compared to 14 % at UK level. England, Wales, Scotland, (14%, 17%, 14%)
House price growth in Northern Ireland breaks all records (in UK)
Section 75 of the Northern Ireland Act 1998 (the Act) places the following
statutory requirements on each public authority:
(1) A public authority shall in carrying out its functions relating to Northern
Ireland have due regard to the need to promote equality of opportunity-
a) between persons of different religious belief, political opinion,
racial group, age, marital status or sexual orientation;
b) between men and women generally;
c) between persons with a disability and persons without; and
d) between persons with dependants and persons without.
(2) Without prejudice to its obligations under subsection (1), a public
authority shall in carrying out its functions relating to Northern Ireland
have regard to the desirability of promoting good relations between
persons of different religious belief, political opinion or racial group.
Schedule 9 of the Act sets out the provisions for the enforcement of these
duties, including the key elements of an equality scheme. Equality
schemes must show ‘how the public authority proposes to fulfil the duties
imposed by Section 75’.
EQIAs need carried out
In the context of the Section 75 duties, an Equality Impact Assessment
(EQIA) is a thorough and systematic analysis of a policy, whether that
policy is written or unwritten, formal or informal, and irrespective of the
scope of that policy or the size of the public authority.

11. NILS Mortality Database
In addition …
NILS Mortality Database
Deaths since 2001 Linked to Census Records
65,000 deaths
Main NILS has 17,500 deaths
Larger size means more detailed analyses of data – e.g. cause of death, geographical area

12. What Research can be done? (Example Projects)
Temperature-related mortality and housing in Northern Ireland.
Lone mothers at time of birth: who are they? An exploration of their socio-economic and household characteristics.
The distribution of lung cancer deaths in Northern Ireland by population and household type.
Describing and Modelling Internal Migration in NI using the NILS: Individuals, Households and Places

13. What Research can be done? (Example Projects)
Mortality amongst residents of nursing and residential homes.
Admission of older people to residential and nursing homes.
Socio-demographic and area correlates of suicides in NI.
Alcohol-related deaths.
Denomination differences in health and short-term mortality in NI.
Area influences on health: does the extent of religious segregation matter?
Socio-economic and cultural influences on the reporting of self-reported health.
Relationship between the self-reported health questions and short-term mortality.
Emigration from NI and effect on the spatial distribution of health.
Relationship between unemployment and health.
Deprivation and Health – Resilience & comparison with Scotland.

14. Future Direction (New Data)
Would like to add in more data
E&W Cancer Registrations
Scotland Hospital Episodes
Potential Datasets:
Dental data
Cancer screening data
Hospital episodes
Prescribing data
Child Health Data, Maternity Data
School Exam Data
Social Services Benefits Data

15. Management of the NILS Funded by the HPSS RDO and DHSS&PS
Began work in 2003
Launched December 2006
Data Custodian is Registrar General for NI
NILS Steering Group
Research Approvals Group
Research Support Unit in early 2008
ESRC/RDO Jointly funding research

16. Management of the NILS (Legal/Ethical/Security)
All data processed under the law
1969 Census Act (amendment)
Birth and Death Registration
Information Commissioner Northern Ireland advice
HPSS legislation
ORECNI ethical approval for database and associated research
Sensitive nature of data
Legal restrictions on staff
Data held and processed in highly secure IT environment (biometric access etc…)

17. Access Arrangements Come and talk to us Complete an Application form
Get Research Approvals Group Approval
Once approved
Work in Secure Environment in McAuley House
Can analyse non-identifiable individual records
Complete Analysis (with assistance if required) and generate output
All output checked for Disclosure

18. Some Initial Findings Fertility Mortality Migration
Average spacing between births 34 months
Catholic General Fertility Rate higher than Protestant
Widow(er)hoods – 90% women, 80% of men survived partner by 4+ years
Majority of NI moves are between Urban Areas
Average distance moved is 4 miles
20% of people moved up (in terms of bedrooms)

19. Dr Dermot O’Reilly Epidemiology Research Group
Centre for Clinical & Population Sciences
Queen’s University of Belfast

20. Contact Details Mrs Máire Brolly 028 9034 8131 nils.nisra@dfpni.gov.uk
Dr Dermot O’Reilly

21. The Northern Ireland Longitudinal Study
Mrs Máire Brolly & Dr David Marshall (NISRA - NILS)
Dr Dermot O’Reilly (QUB)