ObjectivePatients with subarachnoid hemorrhage (SAH) usually have prolonged hospitalizations due to the need to closely monitor their neurological status. Therefore, these patients have higher risk of experiencing hospital-acquired complications (HACs), which can complicate their clinical course and recovery. However, there is no evidence on the impact of HACs of long-term clinical outcomes. We aimed to identify if HACs are independent risk factors for poor clinical outcomes at 12–18 months of follow-up. Patients and MethodsRetrospective analysis of 323 patients with SAH diagnosis from 2013 until June 2018. We collected patient-related factors (age, sex, body mass index (BMI), ethnicity), comorbidities (hypertension, smoke status, diabetes, coronary heart diseases, prothrombotic diseases and hypercholesterolemia), clinical variables (Hunt-Hess grade, modified Fisher grade, treatment, delayed cerebral ischemia), aneurysm characteristics (location, size) and HACs (pneumonia, deep vein thrombosis (DVT), urinary tract infection (UTI), external ventricular drainage (EVD) infections, sepsis, hyponatremia and acute respiratory distress syndrome). Poor outcomes were defined as mRS ≥ 3. Results204 patients were included in the primary analysis. 82 (40.2%) experienced one or more HACs during their hospital course. Patients that developed HACs have significantly increased ICU (12.1 ± 6.6 vs 24.3 ± 23.6, p < .001) and hospital (18.7 ± 14.2 vs 35.3 ± 26.3, p < .001) length of stays. Moreover, patients with HACs had significant higher rates of delayed cerebral ischemia, non-routine discharge and poor outcomes at 90 days. 177 patients had complete follow-ups at 12–18 months, HACs were independent risk factors for poor functional outcomes at 12–18 months after adjusting for demographic, comorbidities and clinical variables [OR = 3.205, 95% CI 1.231−8.347, p < 0.001]. ConclusionsHACs are an independent risk factor of sustaining poor clinical outcomes 12–18 months after a SAH. Furthermore, HACs are significantly related with the occurrence of DCI, with non-routine discharge and 90-day poor functional outcomes.