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prevalence rates reported were from Italy; 3.3 per 1000 in Sicily23 and 3.01 per 1000 in the Aeolian
Islands24, although the authors of both studies suggest that prejudice towards people with epilepsy
and the low prevalence rates may result from patients’ desire to conceal the diagnosis to avoid
perceived social disadvantages. In the Rochester study the prevalence of active epilepsy, calculated
at 10-year intervals over 50 years, ranged from 2.7 per 1000 in 1940 to 6.8 per 1000 in 198025.

More recent studies using patient reports from Norway (crude prevalence rate 11.7 per 1000; active
epilepsy 6.7 per 1000)26 and Ireland (life prevalence 10 per 1000; treated epilepsy 8.39.0 per
1000)23 suggest higher prevalence rates in western countries. The median lifetime prevalence in
developed countries has been estimated to be 5.8 per 1000 (range 2.712.4) with a median
prevalence of active epilepsy of 4.9 per 1000 (range 2.310.3)2. In the Italian study the crude
prevalence of epilepsy in 2011 was 7.9 per 1000 (men 8.1, women 7.7) with the prevalence being
highest in those aged <25 years and ≥75 years20.

The lifetime prevalence of seizures (the risk of having a non-febrile epileptic seizure at some point
in an average lifetime) is between 2 and 5%. The difference between the lifetime prevalence and
prevalence of active epilepsy implies that for the majority either the condition remits or the patient
dies.

Evidence from community-based studies have shown that 70−80% of people with epilepsy will
achieve remission, usually in the early course of the condition and indeed the longer epilepsy
remains active the poorer the prognosis28. (Prognosis is reviewed in Chapter 36.)

Factors influencing incidence and prevalence

Most incidence studies show that epilepsy is more common in males than females, both in
developed and resource-poor countries but this difference is rarely significant29.

In the systematic review of incidence studies, the median annual incidence of epilepsy was 50.7
per 100,000 for males and 46.2 per 100,000 for females17. Incidence rates also vary considerably
with age. Studies in the industrialised world consistently show a bimodal distribution. There is a
very high incidence in the first year of life and in early childhood, with a relative decrease in
adolescence. Incidence is at its lowest between the ages of 20 and 40 and steadily increases after
age 50, with the greatest increase seen in those over age 80. There is evidence that the incidence of
epilepsy is now higher in elderly people than children30.

The temporal changes in incidence of epilepsy in Finland between 1986 and 2002 were examined
using a nationwide database. The total incidence decreased significantly from
71.6 to 52.9 per 100,000 per year during that time. The incidence decreased in children and adults
but increased in the elderly, particularly in women31.

Incidence and prevalence rates of epilepsy tend to be higher in resource-poor countries. The highest
reported rates of epilepsy have been found in South America; in a well designed study in Ecuador
the incidence rate was 122 per 100,000/year32.

The prevalence of epilepsy appears to be lower in Africa, while studies from Asia (mainly China
and India) have demonstrated rates similar to those in the Western world. Moreover there can be
marked variation in incidence and prevalence rates between different regions within the same
country, although most but not all studies have shown that rates are higher in rural than in urban
areas15. No consistent racial differences in epilepsy have been found and in a study of incidence in