The Norwegian society for hypertension got a surprisingly difficult question: What is the prevalence of hypertension per age group in Norway?
You would certainly think there was a straight forward answer to that question, and that we should know it. You don't even predict the question, because you think it has to be published in an easily accessible form. Any way, it is not. The best current evidence is only published in Norwegian, so in the interest of the hypertension community here is the short story.
2000-2003 the Norwegian institue of public health performed a health survey in selected counties and this was published in the journal of the norwegian medical association(Pubmed: Tidsskr Nor Laegeforen. 2007 Oct 4;127(19):2537-41.). The data is in table 4. What it says is that 17.4 % of men and 3.2 % of women aged 30 had a systolic blood pressure higher than 140 mmHg and/or a diastolic blood pressure higher than 90 mmHg. The number of hypertensives gradually increased to 65.4 % of men and 69% of women at the age of 75 years.
Thanks to my collegues in the Hypertension society for helping me find the data. Especially Randi Selmer at the Norwegian institute of public health who provided (and co-authored) the paper.
In the coming year we can look forward to the publication of the whole population data from the health survey in the county Nord-Trøndelag study number 3 (HUNT-3). There still will not be a definitive answer to the question of the prevalence of hypertension in Norway, but age group coverage will be down to 13 years of age.
So, as far as I can see, I have a 82.6 % chance of not having hypertension (not counting that I am rather stressed at the moment, which would bring it down to -10% somewhere).