Dermot O'Reilly

Long working hours and risk of coronary heart disease and stroke : a systematic review and meta-analysis of published and unpublished data for 603 838 individuals

BACKGROUND Long working hours might increase the risk of cardiovascular disease, but prospective evidence is scarce, imprecise, and mostly limited to coronary heart disease. We aimed to assess long working hours as a risk factor for incident coronary heart disease and stroke. METHODS We identified published studies through a systematic review of PubMed and Embase from inception to Aug 20, 2014. We obtained unpublished data for 20 cohort studies from the Individual-Participant-Data Meta-analysis in Working Populations (IPD-Work) Consortium and open-access data archives. We used cumulative random-effects meta-analysis to combine effect estimates from published and unpublished data. FINDINGS We included 25 studies from 24 cohorts in Europe, the USA, and Australia. The meta-analysis of coronary heart disease comprised data for 603,838 men and women who were free from coronary heart disease at baseline; the meta-analysis of stroke comprised data for 528,908 men and women who were free from stroke at baseline. Follow-up for coronary heart disease was 5·1 million person-years (mean 8·5 years), in which 4768 events were recorded, and for stroke was 3·8 million person-years (mean 7·2 years), in which 1722 events were recorded. In cumulative meta-analysis adjusted for age, sex, and socioeconomic status, compared with standard hours (35-40 h per week), working long hours (≥55 h per week) was associated with an increase in risk of incident coronary heart disease (relative risk [RR] 1·13, 95% CI 1·02-1·26; p=0·02) and incident stroke (1·33, 1·11-1·61; p=0·002). The excess risk of stroke remained unchanged in analyses that addressed reverse causation, multivariable adjustments for other risk factors, and different methods of stroke ascertainment (range of RR estimates 1·30-1·42). We recorded a dose-response association for stroke, with RR estimates of 1·10 (95% CI 0·94-1·28; p=0·24) for 41-48 working hours, 1·27 (1·03-1·56; p=0·03) for 49-54 working hours, and 1·33 (1·11-1·61; p=0·002) for 55 working hours or more per week compared with standard working hours (ptrend<0·0001). INTERPRETATION Employees who work long hours have a higher risk of stroke than those working standard hours; the association with coronary heart disease is weaker. These findings suggest that more attention should be paid to the management of vascular risk factors in individuals who work long hours. FUNDING Medical Research Council, Economic and Social Research Council, European Union New and Emerging Risks in Occupational Safety and Health research programme, Finnish Work Environment Fund, Swedish Research Council for Working Life and Social Research, German Social Accident Insurance, Danish National Research Centre for the Working Environment, Academy of Finland, Ministry of Social Affairs and Employment (Netherlands), US National Institutes of Health, British Heart Foundation.

Mental health in Northern Ireland: have “the Troubles” made it worse?

Objectives: To measure the effects of the civil unrest (the Troubles) on the mental health of the general population of Northern Ireland. Design: A secondary analysis of a nationally representative population survey conducted in 1997. Setting: Northern Ireland. Methods: This is an analysis of the 1694 respondents (aged 16–64) who had their mental health assessed using the 12 question version of the General Health Questionnaire (GHQ). The effects of the Troubles was based on the responses to two survey questions; one asking about the impact on respondent’s area; the second about the impact on the life of the respondent or their family. To model simultaneous effects, multiple logistic regression models were constructed with GHQ case as the dependent variable, the impact of the Troubles questions as independent variables, and the demographic, socioeconomic, and health related factors as covariates. Results: 21.3% (361) of respondents said that the Troubles had either “quite a bit” or “a lot” of impact on their lives or the lives of their families and 25.1% (418) reported a similar impact on their area of residence. The likelihood of psychological morbidity increased the greater the extent to which the Troubles affected the respondent’s area or life, the association being stronger for the second factor. Neither demographic nor socioeconomic factors significantly diminished this relation although adjusting for health related factors did attenuate the magnitude of the odd ratios especially for the effects of the Troubles on area of residence. Conclusion: It is probable that mental health of the population of Northern Ireland has been significantly affected by the Troubles. Whether this is attributable to the violence in itself or to other aspects of the Troubles is unclear and whether any additional inputs from psychiatric services are needed requires further study.

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.

Evidence of prostate cancer screening in a UK region.

To examine the pattern of use of prostate‐specific antigen (PSA) testing in a UK region, where National Health Service policy does not recommend screening for prostate cancer.

Cohort description: The Northern Ireland Longitudinal Study (NILS)

Northern Ireland has traditionally been well served with cross-sectional studies, including episodic surveys of poverty and social exclusion, and of health and social well-being. However, such studies are of limited use in either analysis of life-course transitions or in the separation of cause and effect, both important goals of current research strategies where renewed interest in equity and social exclusion is stimulating research into the effects of disadvantage on individuals over time. This is all the more urgent given the increased social and geographical mobility and greater fluidity in people’s lives. Such information can only be derived longitudinally, and there was a dearth of such large-scale general purpose studies in Northern Ireland. Information had not been included in the three British Birth Cohort studies of 1946, 1958 and 1970 and although other longitudinal studies, such as PRIME and Young Hearts, are available they were designed to answer research questions related to specific diseases. Although the British Household Panel Study has recently been extended to include Northern Ireland and there is now a Northern Ireland component to the Millennium Birth Cohort Study, neither is large enough to function as a general purpose longitudinal study to meet the general research or policy needs of Northern Ireland. In the early 2000s, a group of senior statisticians from the Northern Ireland Statistics and Research Agency (NISRA) and academics was convened to estimate the cost of a Northern Ireland Longitudinal Study (NILS), equivalent to others either already available in England and Wales or, at the time, in development in Scotland. The aim was to have a multi-cohort study that would fulfil a range of academic and policy-related purposes, with a sample size large enough to enable robust analysis of population sub-groups and of areas of policy relevance. Because the experience of the Scottish Longitudinal Study (SLS) team had shown that linkage to the 1991 census would incur considerable costs, especially if social class for earlier years had to be recoded to the NS-SEC classification used in the 2001 census, it was decided to start with the 2001 census. Funding for the establishment and maintenance of NILS (and its sister study NIMS, see below) was jointly secured in 2003 from the Department of Health, Social Services and Public Safety and the Research and Development Office of the then Health and Personal Social Services. All funding for the development and maintenance of NILS and NIMS now comes from the Health and Social Care Research and Development Division of the Public Health Agency (HSC R&D Division). NISRA helps to fund the NILS/ NIMS project both through the provision of accommodation to house all aspects of the NILS/NIMS operation and staff to maintain and develop the databases and provide strategic management of the project. Both NILS and NIMS were launched in December 2006.

Consultation charges in Ireland deter a large proportion of patients from seeing the GP: results of a cross-sectional survey

Objective: To estimate the effect of a consultation charge on the health-seeking behaviour of patients. Methods: Cross-sectional survey of patients carried out in Northern Ireland, where services are free at the point of delivery, and the Republic of Ireland, where 70% of the population are charged a consultation fee to see the general practitioner (GP). Results: There were 11 870 respondents to the survey (response rate 52%). In the Republic of Ireland, 18.9% of patients (4.4% of non-paying patients and 26.3% of paying patients) had a medical problem in the previous year but had not consulted the doctor because of cost; this compares with only 1.8% of patients in Northern Ireland. Because those in the Republic of Ireland on low income are entitled to free care, the effects of the consultation charge were most marked in the middle of the income distribution, with such patients being over four times as likely to have been deterred as those in the most affluent group. However, amongst paying patients, it was the poorest and those with the worst health who were most affected. Compared to the most affluent patients and those without depression, the likelihood of not having seen the GP due to cost was 6.75 (95% confidence interval [CI] 3.79, 11.09) for the poorest patients and 2.01 (95% CI 1.53, 2.52) for those with depression. Conclusion: Even in countries with exemptions for the poor and more vulnerable, a consultation charge can deter a large proportion of poorer and less healthy patients from seeing their GP.

Psychotropic medications and the transition into care: a national data linkage study

To determine whether excessive and often inappropriate or dangerous psychotropic drug dispensing to older adults is unique to care homes or is a continuation of community treatment.

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.

Childhood residential mobility and health in late adolescence and adulthood: findings from the West of Scotland Twenty-07 Study

Background The relationship between childhood residential mobility and health in the UK is not well established; however, research elsewhere suggests that frequent childhood moves may be associated with poorer health outcomes and behaviours. The aim of this paper was to compare people in the West of Scotland who were residentially stable in childhood with those who had moved in terms of a range of health measures. Methods A total of 850 respondents, followed-up for a period of 20 years, were included in this analysis. Childhood residential mobility was derived from the number of addresses lived at between birth and age 18. Multilevel regression was used to investigate the relationship between childhood residential mobility and health in late adolescence (age 18) and adulthood (age 36), accounting for socio-demographic characteristics and frequency of school moves. The authors examined physical health measures, overall health, psychological distress and health behaviours. Results Twenty per cent of respondents remained stable during childhood, 59% moved one to two times and 21% moved at least three times. For most health measures (except physical health), there was an increased risk of poor health that remained elevated for frequent movers after adjustment for socio-demographic characteristics and school moves (but was only significant for illegal drug use). Conclusions Risk of poor health was elevated in adolescence and adulthood with increased residential mobility in childhood, after adjusting for socio-demographic characteristics and school moves. This was true for overall health, psychological distress and health behaviours, but physical health measures were not associated with childhood mobility.

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.