Valproic acid and socioeconomic associations in Swedish women with epilepsy 2010-2015

We investigated the correlation between socioeconomic status and the prescription of Valproic acid (VPA) in women of fertile age in Sweden.

This is a registered-based cohort study including all women living in Sweden aged 18-45 years in the years 2010-2015, with a diagnosis of epilepsy and no intellectual disability (n = 9143). Data were collected from the National Patient Register, the Drug Prescription Register, and the Longitudinal integration database for health insurance and labor market studies (LISA).

Women with only 9 years of school were more often prescribed VPA than women with a University degree (12.9% compared to 10.7% in 2015 [p = 0.015]). Similar differences were seen between the lowest and highest income group (16.6% compared to 12.7% in 2015 [p < 0.001]). The odds of having a VPA prescription in 2015 was 1.59 (p < 0.001) in women with 9 years of school compared to women with a University degree, and 1.60 (p < 0.001) in the lowest income group relative to the highest income group after adjusting for age. From 2010 to 2015, the proportion with VPA prescription in the whole cohort diminished with an absolute reduction of -2.2% (p < 0.001). The decrease was similar among the different education and income groups (p = 0.919 and p = 0.280).

The results indicate that the increased knowledge on VPA teratogenicity was implemented across socioeconomic strata in the Swedish healthcare system. Women with lower income or education level remained more frequent VPA users. Whether this difference reflects epilepsy type or severity, or socioeconomic disparities, merit further study.