Social deprivation and prevalence of epilepsy and associated health usage.

Abstract

To examine the relation between social deprivation and the prevalence of epilepsy and associated morbidity using hospital activity data as a proxy. The study was conducted in the health district of South Glamorgan, United Kingdom (population 434 000). Routinely available hospital data (inpatient and outpatient), an epilepsy clinic database, and mortality data underwent a process of record linkage to identify records relating to the same patient and to identify patients with epilepsy. Each patient was allocated a Townsend index deprivation score on the basis of their ward of residence. Age standardised correlations were calculated between deprivation score and prevalence of epilepsy, inpatient admissions, and outpatient appointments. Standardised mortality ratios (SMR) were also calculated. All analyses were performed on two cohorts: (1) all patients with epilepsy and (2) those patients with epilepsy without any underlying psychiatric illness or learning disability. The prevalence of epilepsy ranged between 2.0 and 13.4 per 1000 with a median of 6.7. There were positive correlations between social deprivation and prevalence in both populations: (1) r=0.75 (p<0.001) and (2) r=0.70 (p<0.001). After standardising for underlying prevalence there were also correlations for mean inpatient admissions: (1) r=0.62 (p<0.001), (2) r=0.59, (p<0.001) and for outpatient appointments: (1) r=0.53, (p=0.001) and (2) r=0. 51 (p=0.001). The SMR for those deprived was (1) 1.66 (95% confidence interval (95% CI) 1.27-2.05) and (2) 1.80 (95% CI 0.71-1. 67). For the population as a whole (with and without epilepsy) the SMR was 1.25 (95% CI 1.27-2.32). This study shows a strong correlation between the prevalence of epilepsy and social deprivation and weaker correlations between social deprivation and mean hospital activity.