Neurosurgery 98:1095–1102, 2026
This retrospective, population-based study analyzes clinical outcomes after nontraumatic subarachnoid hemorrhage (SAH) among 43,315 patients with documented nicotine dependence versus patients without substance use disorders. Using the TriNetX network with propensity score matching, primary endpoints included mortality, vasospasm, hydrocephalus, and delayed cerebral ischemia (DCI), with nicotine dependence associated with significantly higher hazards for all outcomes.
The manuscript details methods, matching variables, statistical analyses, mechanistic discussion of nicotine’s vascular effects, and limitations inherent to large electronic health record databases. Conclusions emphasize that nicotine dependence predicts worse SAH outcomes and support prioritizing smoking cessation counseling as part of long-term patient management.
Study focus: Clinical outcomes after nontraumatic subarachnoid hemorrhage (SAH) in adults with nicotine dependence versus those with no substance use disorder diagnoses.
Data source & cohort: TriNetX electronic medical record network analysis of adults (≥18) with ICD-10 I60 (nontraumatic SAH) from 2004–2024; 43,315 had nicotine dependence (F17) out of ~210k+ SAH patients.
Methods: Used 1:1 propensity score matching to balance demographics, comorbidities, lab/substance testing, and SAH severity (NIS-SAH Severity Score elements), then applied Cox proportional hazards and Kaplan–Meier survival analyses.
Mortality risk: Nicotine dependence associated with higher post-SAH mortality hazard (HR ≈ 1.24–1.25, statistically significant).
Vasospasm risk: Nicotine dependence associated with higher hazard of vasospasm (HR ≈ 1.47–1.49, statistically significant).
DCI risk: Nicotine dependence associated with higher hazard of delayed cerebral ischemia (DCI) (HR reported ≈ 1.30–1.35, statistically significant).
Hydrocephalus risk: Nicotine dependence associated with higher hazard of newly diagnosed hydrocephalus (HR ≈ 1.27, statistically significant).
Clinical implication: Elevated risks linked to nicotine dependence underscore the importance of smoking cessation counseling for long-term management after SAH.


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