Abstracts

Data from population based studies suggest that the incidence of convulsive status epilepticus (CSE) is higher in non-white compared to white subjects. However, ethnicity effects may be related to socioeconomic factors. In the published literature, the study with the highest reported incidence of CSE was conducted in a predominantly black, economically deprived population. Thus, we hypothesised that the incidence of CSE previously reported in non-white ethnic groups may be related to socioeconomic status. From the North London convulsive STatus EPilepticus in childhood Surveillance Study (NLSTEPSS), a prospective population based study, we report on the effect of ethnicity and socioeconomic status on the incidence of CSE in childhood. The methodology for ascertainment of cases and data collection has been previously described in detail (AES 2003). Excluding neonates, children aged less than 16 years with CSE within North London were identified using a multi-tiered notification system. Data on each episode were collected within 2 weeks of notification. Capture-recapture methodology was used to estimate degree of ascertainment. Home post codes of children were used to assign to each child an Index of Multiple Deprivation 2004 (IMD 2004) score of socioeconomic status. Poisson multivariate regression analysis was used to investigate the relationships between incidence of CSE and socioeconomic status, ethnicity and age. 176 children with lifetime first episodes of CSE were enrolled. The ascertainment adjusted incidence of CSE is approximately 18-20/100,000 children/ year. Ethnicity and socioeconomic status are independently associated with the incidence of CSE. Asian children are 2.1 times more likely (p[lt]0.0005), but black children are as likely (OR 1.3, p=0.2), to have an incident episode of CSE compared to white children. For each one point increase in IMD 2004 (worsening socioeconomic status) there is a 3% cumulative increased risk of CSE irrespective of ethnicity (p=0.003). In addition, the incidence of CSE in each ethnic group is significantly related to socioeconomic status but this effect is least amongst Asian children (p=0.05). The relationship between ethnicity and CSE is complex and is likely to be related to both genetic and socioeconomic factors. Improvement in socio-economic status may reduce the incidence of CSE and thus reduce morbidity.