DISP-25. Disparities in Adjuvant Care and Survival in Colombian High-Grade Glioma Patients: An IPTW Cohort Analysis

OBJECTIVE Healthcare disparities significantly influence outcomes in patients with high-grade glioma (HGG) across income settings. While Colombia’s universal healthcare model aims to ensure equitable access, the impact of insurance type on treatment completion and survival in HGG remains unexamined. This study aims to assess differences in access to adjuvant treatment and survival outcomes among HGG patients covered under contributory versus subsidized insurance schemes in Bogotá, Colombia. METHODS A retrospective cohort study was conducted, including adult patients with newly diagnosed HGG who underwent surgical management at two neurosurgical referral centers in Bogotá between 2017 and 2021. Patients with recurrent disease at presentation or lost to follow-up after surgery were excluded. Demographic, clinical, surgical, and treatment data were collected. The primary outcome was overall survival, assessed through medical records and the national death registry. A propensity score model with inverse probability of treatment weighting (IPTW) was used to adjust for confounding. Cox proportional hazards and logistic regression models were applied RESULTS A total of 113 patients were included: 88 with contributory and 25 with subsidized coverage. Patients in the subsidized group had significantly lower rates of medical oncology consultation (48% vs. 84%), chemotherapy (28% vs. 68.2%), and radiotherapy (8% vs. 56.3%) (all p<0.001). Median survival was shorter in the subsidized group (9.8 vs. 16.5 months, p=0.006). After IPTW adjustment, subsidized insurance (HR 1.66, p=0.035), subtotal resection (HR 1.58, p = 0.045), and lack of oncology consultation (HR 5.24, p=0.026) independently predicted worse survival. Female sex (OR 2.59, p=0.045) and subsidized coverage (OR 8.21, p<0.001) were associated with failure to complete oncology follow-up. CONCLUSIONS In a universal healthcare setting, disparities in access to adjuvant treatment significantly affect survival in patients with high-grade gliomas. Formal insurance coverage alone does not guarantee equitable care delivery. Reforms aimed at ensuring timely postoperative oncology access are essential to improve outcomes