But no good estimate of the national prevalence has been available until now.
It appears that for acute health problems older people are little different, in terms of prevalence, from younger age groups.
The rate of prevalence can be difficult to determine.
The mean age of prevalence in women is higher than in men by one year, 58 and 59 years old respectively.
The range of prevalence among the centers from 1 percent to 51 percent.
Simple comparisons of prevalence estimates across studies is, therefore, problematic.
The other countries affected have a lower rate of prevalence and also appear to be in control of the situation.
Estimates of prevalence of the condition range from 1.4 to 5.4% in the general population.
Large samples should permit more accurate estimates of prevalence than smaller studies.
Timimi himself cites a range of prevalence that goes from 0.5% to 26% as support for his theory.