Sheelagh Connolly

Area factors and suicide: 5-year follow-up of the Northern Ireland population

BACKGROUND Suicide rates vary markedly between areas but it is unclear whether this is due to differences in population composition or to contextual factors operating at an area level. AIMS 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 was conducted of 1,116,748 non-institutionalised individuals aged 16-74 years, enumerated at the 2001 Northern Ireland census. RESULTS The cohort experienced 566 suicides during follow-up. Suicide risks were lowest for women and for those who were married or cohabiting. Indicators of individual and household disadvantage and economic and health status at the time of the census were also strongly related to risk of suicide. 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. 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.

House value as an indicator of cumulative wealth is strongly related to morbidity and mortality risk in older people: a census-based cross-sectional and longitudinal study

BACKGROUND There has been relatively little research into health inequalities in older populations. This may be partly explained by the difficulty in identifying appropriate indicators of socio-economic status for older people. Ideally, indicators of socio-economic status to be used in studies of health inequalities in older populations should incorporate some measure of life-time socio-economic standing, and house value may fill this role. This study examined whether an indicator of accumulated wealth based on a combination of housing tenure and house value was a strong predictor of ill-health in older populations. METHODS A total of 191 848 people aged > or =65 years and not living in communal establishments were identified from the 2001 Northern Ireland Census and followed for 5 years. Self-reported health and mortality risk by housing tenure/house value groupings were examined while controlling for a range of other demographic and socio-economic characteristics. RESULTS Housing tenure/house value was highly correlated with other indicators of socio-economic status. Public-sector renters had worse self-reported health and higher mortality rates than owner occupiers but significant gradients were also found between those living in the highest- and lowest-valued owner-occupier properties. The relationship between housing tenure and value was unchanged by adjustment for indicators of social support and quality of the physical environment. Adjustment for limiting long-term illness and self-reported health at baseline narrowed but did not eliminate the health gains associated with living in more expensive housing. CONCLUSIONS House value of residence is an accessible and powerful indicator of accumulated wealth that is highly correlated with current health status and predictive of future mortality risk in older populations.

Unlinked vital events in census-based longitudinal studies can bias subsequent analysis

OBJECTIVE To examine the potential biases arising from the nonlinkage of census records and vital events in longitudinal studies. STUDY DESIGN AND SETTING A total of 56,396 deaths of residents of Northern Ireland in the 4 years after the 2001 Census were linked to the 2001 Census records. The characteristics of matched and nonmatched death records were compared using multivariate logistic regression. Subject attributes were as recorded on the death certificate. RESULTS In total, 3,392 (6.0%) deaths could not be linked to a census record. Linkage rates were lowest in young adults, males, the unmarried, people living in communal establishments, or living in areas that were more deprived or had recorded low census enumeration. For those aged less than 65 years at census, this linkage would exclude from analysis 20.2% of suicides and 19.7% of deaths by external causes. CONCLUSION The nonlinkage of census and death records is a combination of nonenumeration at census and deficient information about the deceased recorded at the time of death. Unmatched individuals may have been more disadvantaged or socially isolated, and analysis based on the linked data set may therefore show some bias and perhaps understate true social gradients.

Area of residence and alcohol-related mortality risk: a five-year follow-up study.

AIMS To examine differences in alcohol-related mortality risk between areas, while adjusting for the characteristics of the individuals living within these areas. DESIGN A 5-year longitudinal study of individual and area characteristics of those dying and not dying from alcohol-related deaths. SETTING The Northern Ireland Mortality study. PARTICIPANTS A total of 720,627 people aged 25-74, enumerated in the Northern Ireland 2001 Census, not living in communal establishments. MEASUREMENTS Five hundred and seventy-eight alcohol-related deaths. FINDINGS There was an increased risk of alcohol-related mortality among disadvantaged individuals, and divorced, widowed and separated males. The risk of an alcohol-related death was significantly higher in deprived areas for both males [hazard ratio (HR) 3.70; 95% confidence interval (CI) 2.65, 5.18] and females (HR 2.67 (95% CI 1.72, 4.15); however, once adjustment was made for the characteristics of the individuals living within areas, the excess risk for more deprived areas disappeared. Both males and females in rural areas had a reduced risk of an alcohol-related death compared to their counterparts in urban areas; these differences remained after adjustment for the composition of the people within these areas. CONCLUSIONS Alcohol-related mortality is higher in more deprived, compared to more affluent areas; however, this appears to be due to characteristics of individuals within deprived areas, rather than to some independent effect of area deprivation per se. Risk of alcohol-related mortality is lower in rural than urban areas, but the cause is unknown.

Variation in care home admission across areas of Northern Ireland

BACKGROUND much has been written about the demographic and health characteristics which act as risk factors for care home admission in the UK. However, few studies have examined variation in care home admission rates across areas, whilst controlling for the demographic and health characteristics of the individuals living within these areas. This is surprising given that decisions which affect admission are often taken at the local level. The aim of the study was to determine if there were variations in care home admission rates across trusts in Northern Ireland, once adjustment had been made for the demographic and health characteristics of the individuals residing within these areas. METHODS a retrospective cohort study was undertaken, using data from the Data Retrieval in General Practice (DRGP) project in Northern Ireland, to identify a cohort of individuals aged 65 and over and living in the community at the outset of the study. A total of 28,064 individuals were followed up for 5 years to identify those who subsequently entered a nursing or residential care home. Controlling for the demographic, household composition and health characteristics of individuals, Poisson regression was used to estimate the incidence rate ratios of care home admission for 10 trusts. RESULTS a total of 24,691 of the initial cohort had complete information for all variables and were included in the final analysis; 1,313 (5.3%) had entered a care home at the end of the 5 years of follow-up. Admission increased significantly with age, and diagnoses of dementia and stroke. Controlling for the age, sex and health composition of individuals, some variations in admission rates were found across trusts. CONCLUSIONS the study has highlighted the importance of age and clinical conditions as risk factors for care home admission. In addition, it appears that the area of residence might be important in determining a persons risk of care home admission. Such differences may be attributable to particular characteristics of the trust, such as the level of deprivation or degree of rurality, or to differing policies in relation to services for older people. More work is required to identify the causes of the differences to allow policies to be implemented to ensure equitable access to care homes across Northern Ireland.

The effect of population movement on the spatial distribution of socio-economic and health status: analysis using the Northern Ireland Mortality Study

This paper examines the impact of population movement on the spatial distribution of socio-economic and health status in Northern Ireland. Five percent of the population cohort changed decile of deprivation between 2000 and 2001, resulting in a net gain in more affluent deciles and a net loss in more deprived areas. In addition, there was a net gain of relatively more affluent people in the more affluent deciles and a net loss of such people from more deprived deciles. However, this selective mobility had a minimal impact on the spatial distribution of health. More pronounced effects may be observed in longer periods of follow-up.

Variation in mortality by country of birth in Northern Ireland: a record linkage study.

The study of health differences between those residing in the same country but originating in different countries is a potential source of insight into the causes of ill-health. Within Northern Ireland, those born in England, Wales, the Republic of Ireland and outside of the British Isles have a lower mortality risk than the Northern Ireland born; however, these differentials are largely explained by the demographic and socio-economic characteristics of these migrants. Conversely, the Scottish born residing in Northern Ireland have higher mortality than the Northern Ireland born, especially from ischemic heart disease, suggesting that the Scottish immigrants maintain the health disadvantage of their country of birth.