Adherence to evidence-based processes of care reduces one-year mortality after aneurysmal subarachnoid hemorrhage (aSAH)

Background: There is limited research on the provision of evidence-based care and its association with outcomes after aneurysmal subarachnoid hemorrhage (aSAH).

Aims: We examined adherence to evidence-based care after aSAH and associations with survival and discharge destination. Also, factors associated with evidence-based care including age, sex, Charlson comorbidity index, severity scores, and delayed cerebral ischemia and infarction were examined for association with survival and discharge destination.

Methods: In a retrospective cohort (2010-2016) of all aSAH cases across two comprehensive cerebrovascular centres, we extracted 3 indicators of evidence-based aSAH care from medical records: (1) antihypertensives prior to aneurysm treatment, (2) nimodipine, and (3) aneurysm treatment (coiling/clipping). We defined 'optimal care' as receiving all eligible processes of care. Survival at 1 year was obtained by data linkage. We estimated (1) proportion of patients and characteristics associated with receiving processes of care, (2) associations between processes of care with 1-year mortality using cox-proportional hazard model and discharge destination with log binomial regression adjusting for age, sex, severity of aSAH, delayed cerebral ischemia and/or cerebral infarction and comorbidities. Sensitivity analyses explored effect modification of the association between processes of care and outcome by management type (active versus comfort measures).

Results: Among 549 patients (69% women), 59% were managed according to the guidelines. Individual indicators were associated with lower 1-year mortality but not discharge destination. Optimal care reduced mortality at 1 year in univariable (HR 0.24 95% CI 0.17-0.35) and multivariable analyses (HR 0.51 95% CI 0.34-0.77) independent of age, sex, severity, comorbidities, and hospital network.

Conclusion: Adherence to processes of care reduced 1-year mortality after aSAH. Many patients with aSAH do not receive evidence-based care and this must be addressed to improve outcomes.