Abstracts

Rationale: In the province of Alberta, epilepsy referral centers face administrative and operational pressures to reduce budgets and bed use. While referral to specialist care is common, many Albertans receive epilepsy care directly from their primary care physician without seeing a neurologist. Our aim was to examine whether referral to an epilepsy centre and to neurological care is associated with a reduction in premature mortality.Methods: Alberta Health Services (AHS) data (hospitalizations, physician claims and provincial health insurance registry for mortality) were used to identify epilepsy cases using a validated case definition. A three-year washout was used to increase the likelihood of identifying incident cases. The physician specialty identifier was used to identify neurologist exposure. Epileptologist exposure was identified through data linkage to the Calgary Epilepsy Program (CEP) database. Case definition satisfaction date was used as the epilepsy index date. Comorbid disease burden at index date was calculated using the validated Epilepsy Specific Comorbidity Index (ESCI). Neurologist exposure impact was estimated using the full provincial dataset. Epileptologist exposure impact was estimated using the population attending the CEP, and compared to those in the CEP catchment area not seen by a neurologist or in the CEP. Accelerated failure time regression using Weibull and log-logistic distributions were used to assess neurologist or epileptologist impact on time to mortality. Covariates in the survival regression model included sex, age and comorbid burden at index date. Akaike Information Criterion was used to choose the most parsimonious regression models.Results: Of 24784 epilepsy cases satisfying eligibility criteria between 2002 and 2014, 5110 died. Mean age at index date was 50.5 years (SD = 19.2 years) and 50% were women. Median ESCI score was 0 (interquartile range 0 – 2). 72% of subjects were exposed to neurologist care. 11,128 (44%) subjects received care in the geographic catchment of the CEP, of these 8,311 (75%) had neurologist exposure including 784 (7%) attendees to the CEP. Patients who received neurologist care had an 8.5% reduction in premature mortality (HR 1.085, p < 0.001). Shorter time to death was associated with being male (HR = 0.959; p < 0.001), older (HR = 0.990; p < 0.001) and higher comorbid burden (HR = 0.951; p < 0.001). Epileptologist care resulted in a 47.9% extension in time to death (HR = 1.479; p < 0.001). In this patient subset shorter time to death was associated with being male (HR = 0.947; p < 0.001), older (HR = 0.985; p < 0.001) and higher comorbid burden (HR = 0.942; p < 0.001).Conclusions: Exposure to neurological care including epilepsy tertiary referrals was associated with greater time to mortality in administratively defined epilepsy when accounting for sex, age at index date and baseline comorbid burden. Additional studies will investigate differences across class of neurological care and comorbid burden over time, as well as relationships between disease severity and referral benefit.