1402. Long-Term Mortality and Epilepsy in Patients After Brain Abscess: A Nationwide Population-based Matched Cohort Study

BACKGROUND: The long-term outcome of brain abscess is unclear. METHODS: We used medical registries to conduct a nationwide population-based matched cohort study to examine the long-term risks of mortality and new-onset epilepsy in patients hospitalized with brain abscess in Denmark from 1982 through 2016. Comparison cohorts from the same population individually matched on age, sex, and residence were identified, as were siblings of all study participants (Figure 1). We computed cumulative incidences and hazard rate ratios (HRRs) for mortality and new-onset epilepsy among brain abscess patients, comparison cohorts and siblings. Population and appendicitis controls had similar characteristics and prognosis why only comparisons between brain abscess patients and population controls are detailed here. RESULTS: We identified 1,384 brain abscess patients with a median follow-up time of 5.9 years (IQR 1.1–14.2). The 1-year, 2–5 year, and 6–30-year mortality of patients after brain abscess was 21%, 16% and 27% when compared with 1%, 6% and 20% for matched population controls (Figure 2). Cox regression analyses adjusted for Charlson comorbidity index score showed 1-year, 2–5 year, and 6- to 30-year HRRs of 17.5 (95% CI 13.9–22.2), 2.61 (95% CI 2.16–3.16) and 1.94 (95% CI 1.62–2.31). The mortality in brain abscess patients compared with population controls was significantly increased regardless of sex or age group except among subjects 80 years or older, and in both previously healthy individuals and immuno-compromised persons. Among the 30-day survivors of brain abscess (median follow-up 7.6 years [IQR 2.2–15.5]), new-onset epilepsy occurred in 32% compared with 2% in matched population controls. Cause-specific Cox regression analysis adjusted for stroke, head trauma, alcohol abuse, and cancer showed 1-year, 2–5-year, and 6–30-year HRRs for new-onset epilepsy of 155 (95% CI 78.8–304), 37.7 (95% CI 23.0–59.9), and 8.93 (95% CI 5.62–14.2) (Figure 3). Comparisons between sibling cohorts suggested no substantial effect of family-related factors on the long-term risk of death or epilepsy after brain abscess (Figure 4). CONCLUSION: Brain abscess is associated with an increased long-term risk of mortality and new-onset epilepsy for several years after the acute infection. [Image: see text] [Image: see text] [Image: see text] [Image: see text] DISCLOSURES: All authors: No reported disclosures.