Prevalence and Incidence of Chronic headache
Prevalance of Chronic headache:
estimated 45 million Americans (NINDS) ... see also overview of Chronic headache.
Prevalance Rate:
approx 1 in 6 or 16.54% or 45 million people in USA [Source statistic for calcuation: "estimated 45 million Americans (NINDS)" -- see also general information about data sources]
Prevalance of Chronic headache:
An estimated 45 million Americans experience chronic headaches. For at
least half of these people, the problem is severe and sometimes disabling. (Source: excerpt from Headache -- Hope Through Research: NINDS)
About prevalence and incidence statistics:
The term 'prevalence' of Chronic headache usually refers to the estimated population
of people who are managing Chronic headache at any given time.
The term 'incidence' of Chronic headache refers to the annual diagnosis rate,
or the number of new cases of Chronic headache diagnosed each year.
Hence, these two statistics types can differ:
a short-lived disease like flu can have high annual incidence but low prevalence,
but a life-long disease like diabetes has a low annual incidence but high prevalence.
For more information see about prevalence and incidence statistics.