Big differences between diagnosed and undiagnosed hypertension in USA and Ireland

According to the World Health Organisation, 1 billion people are affected by hypertension, which makes it a global health issue. There are not a lot of studies comparing hypertension prevalence rates between the United States and Europe, especially in older adults.

In a study we recently published, Irene Mosca and Rose Anne Kenny  compared prevalence rates of diagnosed , measured, total and undiagnosed hypertension among late middle-aged adults in the United States and Ireland. They also sought to identify the most important predictors of hypertension in the two countries and to investigate whether cross-sectional differences in prevalence rates are explained by country differences in behavioural risk factors, such as smoking and drinking.

Data from the Health and Retirement Study and the The Irish Longitudinal Study of Ageing were analysed (n=1,938 and n=1,455 respectively). Both studies used provided comparable information. The prevalence of diagnosed hypertension in the US was 48.6%, compared to 32.4% in Ireland. Undiagnosed hypertension, however was much higher in Ireland (41.2%), compared to 19.7% in the US. In both countries obesity was positively associated with diagnosed, measured and total hypertension and negatively associated with undiagnosed hypertension.

Little of the difference in prevalence rates of diagnosed and undiagnosed hypertension was explained by country differences in behavioural risk factors: even if the Irish had the same level of behavioural risk factors as the average American in this age group, this would explain about 1/4 of the difference of diagnosed and undiagnosed hypertension.

The authors conclude that, overall, differences in the clinical systems, community programmes and environmental and policy support are likely to be important factors behind the identified differences. There is a greater focus on prevention is necessary in Ireland.

What do you think? What might be possible explanations for these differences?

*picture credit and also