Abstract Body (Do not enter title and authors here): Background: Social determinants of health (SDoH) impact access to healthcare and outcomes. Few studies examine SDoH in pediatric pulmonary hypertension (PH) patients.

Hypothesis: Outcomes in pediatric PH patients will differ according to SDoH with increased mortality in those from 1) low Child Opportunity Index (COI) areas or 2) non-local to our specialized quaternary center, with 3) public insurance, 4) limited English proficiency (LEP) and 5) underrepresented races/ethnicities.

Methods: In this single center, retrospective cohort study, pediatric PH patients (<18) with inpatient admission 2012-2021 were identified using ICD-10 codes. Demographics, clinical course and outcomes were compared according to SDoH. Logistic regression, with SDoH separately added, studied associations with mortality at current follow-up, controlling for clinical factors, number of admissions and follow-up length with Bonferroni correction.

Results: Of 1735 pediatric PH patients, 232 (13.4%) died. Median time to last follow-up or death was 35 days (IQR 8, 241). Median age was 215 days (IQR 14, 1716) with etiological subgroups of pulmonary arterial hypertension (275, 15.9%), left heart disease (1169, 67.4%), lung disease (271, 15.6%), thromboembolic (16, 0.9%) and other (4, 0.2%). Patients had a median of 3 complex chronic conditions (IQR 2, 5), ECMO (10.3%), lung (1.5%) or heart transplant (2.8%), tracheostomy (12.1%) and utilized PDE5 inhibitors (29.9%), prostacyclins (1.7%), endothelin receptor antagonists (4.0%) and inhaled nitric oxide (11.9%).

Patients that died had lower COI (median 61.5 [IQR 30.8, 80.3]) vs. those who survived (median 69.0 [IQR 43, 88] p=0.002). Mortality was higher in those with public vs. private insurance (15.5% vs 11.7%, p=0.022). Mortality differed by race/ethnicity (p<0.001); 11.6% in non-Hispanic/Latino White patients, 9.5% ‘another’, 1.7% Asian, 19.6% Black, 9.5% Hispanic/Latino, 4.0% multiracial and 19.2% unknown. Survival for local vs. out of state and LEP patients were similar (p>0.6).

For a 10-point COI increase, adjusted mortality odds were 0.92 lower (95%CI 0.87, 0.98, p=0.009). Patients with Black (1.93 [95%CI 1.2, 3.2] p=0.011) and unknown race (1.99 [95%CI 1.4, 2.9] p<0.001) had higher adjusted odds of mortality vs. White. Payer was not independently associated with mortality.

Conclusions: Black PH patients or those from lower COI areas had higher mortality. Deeper understanding of disparate outcomes is needed to advance health equity.