Although the prevalence of epilepsy among veterans was similar to what has been reported in the literature, those with DRE had a mortality rate higher than the US general population and other veterans.
According to data from an observational cohort study, US veterans with drug-resistant epilepsy (DRE) have higher rates of mortality than the general population, prompting the critical need for appropriate management of DRE in this population. Although used sparingly, those who did utilize comprehensive epilepsy care and diagnostic services had reduced mortality.
The standardized mortality rate (SMR) for individuals with DRE compared with the general US population data was 1.50 (95% CI, 1.47-1.53), with female individuals having higher mortality (1.94; 95% CI, 1.75-2.13) than male individuals (1.49; 95% CI, 1.46-1.52). Furthermore, the SMR for individuals with DRE compared with a cohort of all veterans in Veterans Health Administration (VHA) data was found to be even higher, at 1.56 (95% CI, 1.53-1.59; males: 1.55 [95% CI, 1.47-1.53]; females: 1.93 [95% CI, 1.53-1.59]).
"This excess mortality risk can potentially be assuaged by appropriate referrals for comprehensive evaluation, adequate diagnostic testing, and optimal medication management. Adequate resources should be allocated to care for this vulnerable patient group," lead investigator Zulfi Haneef, MD, MBBS, associate professor, Baylor College of Medicine, and colleagues wrote.
During the study period, 9,640,743 veterans were assessed, 164,435 of whom had epilepsy. Haneef et al examined the association of utilization of care with mortality in a subset of patients with DRE (n = 55,571; 33.8%) with a combined 333,946 person-years at risk during the study period. The case fatality rate was calculated by dividing total deaths by the number of patients with DRE, while age- and sex-specific SMRs were computed as the ratios of the number of observed deaths in patients with DRE divided by the number of expected deaths in the US general population from 2014 to 2019 or the VHA population.
From the ethnicity data gathered, 5.7% (n = 3170) of the cohort were Hispanic or Latino, 91.1% (n = 50,599) were not Hispanic or Latino, 1.5% (n = 842) declined to answer, and 1.7% (n = 960) were recorded as unknown. The cohort included mostly White individuals (71.2%; n = 39,543), followed by Black or African American (20.4%; n = 11,316) and those of mixed-race backgrounds (0.8%; n = 453), among others. In total, 63.8% (n = 5471) of those were recorded as living in urban settings vs rural, highly rural, insular islands, or unknown.
Most patients with DRE (81.1%; n = 45,057) had been seen by a neurology specialist; however, only 15% (n = 8350) of those were seen within an Epilepsy Center of Excellence (ECoE) and only 6% (n = 3357) had an epilepsy monitoring study. Slightly less than half (49.6%; n = 27,546) of the patients had EEG performed and about two-third (66.4%; n = 36,905) of the cohort had MRI. Lower mortality was associated with increased utilization of care, including visits to a neurology clinic or an ECoE, as well as EEG and MRI testing. Mortality was also lower when patients were evaluated at an ECoE compared with a neurology clinic alone.
Using multivariable logistic regression analyses, several factors contributed to increased mortality, including lack of EEG testing (odds ratio [OR], 1.11; 95% CI, 1.05-1.17), lack of MRI (OR, 1.38; 95% CI, 1.31-1.45), EMU testing (OR, 1.17; 95% CI, 1.03-1.33), lack of neurology evaluation (OR, 1.31; 95% CI, 1.23-1.39), age (OR, 1.060; 95% CI, 1.058-1.063), and Charlson-Deyo Comorbidity Index (OR, 1.13; 95% CI, 1.127-1.141). Factors such as female sex (OR, 0.67; 95% CI, 0.60-0.75) and the use of more than 2 antiseizure medications (OR, 0.76; 95% CI, 0.72-0.79) were associated with reduced mortality.