Abstract and Introduction
Abstract
Objective To examine age and gender specific trends in coronary heart disease (CHD) and stroke mortality in two neighbouring countries, the Republic of Ireland (ROI) and Northern Ireland (NI).
Design Epidemiological study of time trends in CHD and stroke mortality.
Setting/patients The populations of the ROI and NI, 1985–2010.
Interventions None.
Main outcome measures Directly age standardised CHD and stroke mortality rates were calculated and analysed using joinpoint regression to identify years where the slope of the linear trend changed significantly. This was performed separately for specific age groups (25–54, 55–64, 65–74 and 75–84 years) and by gender. Annual percentage change (APC) and 95% CIs are presented.
Results There was a striking similarity between the two countries, with percentage change between 1985 and 1989 and between 2006 and 2010 of 67% and 69% in CHD mortality, and 64% and 62% in stroke mortality for the ROI and NI, respectively. However, joinpoint analysis identified differences in the pace of change between the two countries. There was an accelerated pace of decline (negative APC) in mortality for both CHD and stroke in both countries from the mid-1990s (APC ROI −8% (95% CI −9.5 to 6.5) and NI −6.6% (−6.9 to −6.3)), but the accelerated decrease started later for CHD mortality in the ROI. In recent years, a levelling off in CHD mortality was observed in the 25–54 year age group in NI and in stroke mortality for men and women in the ROI.
Conclusions While differences in the pace of change in mortality were observed at different time points, similar, substantial decreases in CHD and stroke mortality were achieved between 1985 and 1989 and between 2006 and 2010 in the ROI and NI despite important differences in health service structures. There is evidence of a levelling in mortality rates in some groups in recent years.
Introduction
The island of Ireland is made up of the Republic of Ireland (ROI) with a population of around 4.6 million inhabitants (2012 figures) and Northern Ireland (NI) with a population of approximately 1.8 million. The past two to three decades have seen a rapid decline in mortality from cardiovascular disease (CVD) and in particular coronary heart disease (CHD) in both the ROI and NI. The ROI has seen an accelerated decrease in CHD mortality since the late 1990s up to 2006, with a similar pattern in NI and the UK in general. However, elsewhere there has been evidence of a slowing down in the trend among younger aged populations, and CHD and stroke mortality trends vary by gender. Previous work has attributed the decrease in CHD mortality to both improvements in treatment uptake and changes in levels of the main cardiovascular risk factors.
Differences in social and economic circumstances and in healthcare systems are likely to contribute to changes in CVD mortality over time. In the ROI, the complex mix of public and private health services provides a two-tier system of healthcare. However, in NI the vast majority of care is provided by the universally accessible National Health Service.
Against this background, the purpose of this work was to compare trends in CHD and stroke mortality in NI and the ROI for the period 1985–2010 and specifically to describe the trends in mortality over time and the pace of change during this period, across age and gender.