Secular trends and population differences in the incidence of epilepsy. A population-based study from Saskatchewan,...

To estimate the incidence of epilepsy in Saskatchewan, Canada between 2005 and 2010 by using provincial administrative health database stratifying gender, age, self-reported Registered Indian (RI) status and secular trends.

An epilepsy database was created through linkage of services claims data from the provincial health database of Saskatchewan, Canada between 2005 and 2010 with a four years washout period (2001-2004). The algorithm used was at least two physician visit with the diagnosis of epilepsy on a different date within 730 days or at least one hospital separation with the diagnosis of epilepsy.

Between 2005 and 2010 the overall crude and age-standardized incidences of epilepsy were 63 new epilepsy patients per 100,000 person-years and 62 per 100,000 person-years respectively. The overall age-specific incidence showed a gradual increase toward a high point in elderly. The incidence rate was slightly higher in men than in women who were older than 39 years. There was a significant downward trend over time in the incidence of epilepsy from 2005 to 2010 in Saskatchewan. For self-declared RI the overall age-standardized incidence of epilepsy was 122 per 100,000 person-years. The rate ratio (RR) incidence difference between self-identified Registered Indian (RI) and non-self-identified RI was 1.6.

The incidence of epilepsy in Saskatchewan, Canada was comparable to previous incidence studies from developed countries. This study is the first Canadian study calculating the secular trends and all-age group incidence of epilepsy and one of the few studies showing the incidence of epilepsy in a self-declared Registered Indian population.