The Northern Ireland Longitudinal Study: Current and Potential Projects Current and Potential Projects NILS Research Support Unit: Fiona Johnston Michael Rosato Dr Gemma Catney

1. 1.Northern Ireland Longitudinal Study (NILS) – c. 28% representative sample of NI population (500,000 individuals), based on health card registrations, linked to:   2001 Census returns   vital events (births, deaths and marriages)   demographic & migration events   contextual and area-based data: capital value of houses and property attributes geographical indicators settlement classifications deprivation measures   Distinct Health & Care datasets 2. 2.Northern Ireland Mortality Study (NIMS) - enumerated population at Census Day (c.1.6 million) linked to 2001 Census returns and subsequently registered mortality data Introduction to the NILS and NIMS

Structure of the NILS

Datasets Routinely Linked Census Dataset 2001GRO Vital Events Datasets Variables include:  Age, sex and marital status  Religion and community background  Family, household or communal type  Housing, including tenure, rooms and amenities  Country of birth, ethnicity  Educational qualifications  Economic activity, occupation and social class  Migration (between 2000 and 2001)  Limiting, long-term illness, self-reported general  health, caregiving  Travel to work - New births into the sample - Births to sample mothers and fathers - Stillbirths to sample mothers - Infant mortality of children of sample mothers and fathers - Deaths of sample members Marriages Widow(er)hoods LPS Property Data 2010Health Card Registration Datasets Capital and rating value (based on 2005 valuation exercise) Variables include: - Household characteristics (no. of rooms, property type, floor space, central heating) and valuation - Estimated capital value - Demographic data: age, status and location - Migration events: immigrants added to the sample emigration of sample members re-entry of sample members to NI migration within NI

1. 1.Research-Driven   Cross-sectional studies: no information on change over time   Other UK LS   Health and socio-demographic profile 2. 2.Legislation   NILS confidentiality protected, and managed by NISRA, under census legislation   NISRA have consulted the following about NILS:   Information Commissioner for Northern Ireland   Office of Research Ethics   Health and Social Care Privacy Advisory Committee 3. 3.Funding   Infrastructure funded by the Health and Social Care Research and Development Division of the Public Health Agency (HSC R&D Division) and NISRA   Support function funded by ESRC and NI Government (OFMDFM) Background to the NILS and NIMS

Distinct Linkage Projects   Potential to link to health services data for specially defined one-off studies; so far successfully linked to Cancer Screening data and Dental Activity data   Legal and ethical scrutiny and privacy protection protocols:   Study period and specific data transfers agreed (DTA)   Legal basis for data transfer (DTA)   Health and Social Care Privacy Advisory Committee informed   Ethics – database modification submitted for non-routine linkage (ORECNI)   One-way encryption methodology:   developed in Scotland to safeguard sensitive census and health and care data   datasets are matched and merged on an encrypted unique identifier   researchers not involved in the linkage processes; only have access to an anonymised dataset

  Over 40 projects currently based on NILS and NIMS databases including analyses on:   mortality (e.g. alcohol-related deaths; self-reported health and mortality);   fertility (e.g. predicting short run changes; characteristics of lone parents);   migration, rural communities and area influences on health. A study of the socio-demographic and area correlates of suicides in NI* (005): results and conclusions from published paper Influence of demographic, socio-economic and area level factors on uptake of routine breast screening in NI** (021): results first presented at SSM 2010 (PhD and submitted for publication) *O’ Reilly, D., Rosato, M., Connolly, S. and Cardwell, C. (2008) Area factors and suicide: 5-year follow-up of the Northern Ireland population. Br J Psychiatry 192(2): **Kinnear, H., Uptake of Breast Screening: Where You live Also Matters. Presented at Society for Social Medicine Conference, QUB, Sept 2010 Current Projects

Background: Suicide rates vary between areas: is this due to characteristics of people (composition) or to the characteristics of the area itself (context)? Aim: To determine if area factors are independently related to suicide risk after adjustment for individual and family characteristics. Method: A 5-year record linkage study, based on the NIMS database, was conducted of c. 1.1 million non-institutionalised individuals aged 16–74 years, enumerated at the 2001 Northern Ireland Census. - data anonymised and held in a safe setting Area Factors & Suicide (i)

Results: 1. 1.The cohort experienced 566 suicides during follow-up Suicide risks: i. i.lowest for women and for those who were married or cohabiting; ii. ii.strongly related to individual and household disadvantage and economic and health status The higher rates of suicide in the more deprived and socially fragmented areas disappeared after adjustment for individual and household factors There was no significant relationship between population density and risk of suicide. Area Factors & Suicide (ii)

Conclusions: Differences in rates of suicide between areas are predominantly due to population characteristics rather than to area-level factors, which suggests that policies targeted at area-level factors are unlikely to significantly influence suicides rates. Paper published in British Journal of Psychiatry (2008) Area Factors & Suicide (iii)

Suicide (Daily Mirror)

Background:  All women aged between invited once every 3 years for breast screening in NI  Current uptake rate in UK is about 76-77%  Uptake is lower in inner city areas (London ~ 64%) Aim: To describe and explain demographic, socio-economic and area-level variations in attendance at breast screening for women who were routinely invited during the period. Method: Linking of 2 highly sensitive datasets (NILS and Breast Screening data) and therefore involved following processes:  ORECNI ethical approval  PAC commendation  one-way encryption  all analyses carried out in NISRA – safe setting Uptake of Breast Screening

Age, marital status, general health Demographic factorsUptake rates % % % Married78.0% Never married66.7% Separated/widowed/divorced67.5% Good general health77.6% Fairly good75.3% Not good68.1%

Housing tenure, car access, educ. & NSSEC Socio-economic factorsUptake rates Owner occupier78.0% Private renting 66.9% Social renting61.3% 2+ cars80.3% 1 car74.9% No car60.1% Employed75.9% Unemployed63.9%

Settlement Bands (A-H) showed Belfast Metropolitan Area different from rest Settlement bands (U,I,R) showed uptake lower in urban and highest in rural areas AreaUptake rates Belfast Metropolitan Area68.3% Rest of NI78.7% Eastern70.1% Northern79.3% Southern78.3% Western78.1%

  Inter-Censal Migration Flows   Mortality after death of a spouse: Is risk the same for all groups?   Religion, fertility and space: impacts on the future school population of Northern Ireland.   DLPs:   The Northern Ireland Electronic Prescribing and Eligibility System (EPES) data: use of antibiotics by demographic and area characteristics (approved)   Northern Ireland Cancer Registry data (feasibility discussions in place) Future and Pending Projects

The help provided by the staff of the Northern Ireland Longitudinal Study and the Northern Ireland Mortality Study (NILS and NIMS) and the NILS Research Support Unit is acknowledged. The NILS and NIMS are funded by the Health and Social Care Research and Development Division of the Public Health Agency (HSC R&D Division) and NISRA. The NILS-RSU is funded by the ESRC and Northern Ireland Government. The authors alone are responsible for the interpretation of the data. Acknowledgements

NILS Research Support Unit Northern Ireland Statistics and Research Agency McAuley House 2-14 Castle Street Belfast BT1 1SA Tel: Website: nils-rsu.census.ac.uk