Individual and composite sociodemographic inequalities in treatment, survival, and survival improvement in glioblastoma: An observational study

Sociodemographic factors are important determinants of cancer management, but their combined impact in glioblastoma remains unclear. Data from the Surveillance, Epidemiology, and End Results database were used to evaluate the associations between selected individual sociodemographic factors (sex, marital status, household income, and residence) and treatment patterns and survival outcomes in patients with glioblastoma. A composite sociodemographic risk score (0-4) was constructed based on adverse prognostic factors (male sex, unmarried status, low income, and rural residence), and patients were stratified into low-, moderate-, and high-risk groups. External validation was performed using an independent cohort. Temporal analyses were conducted to assess differences in survival improvement across sociodemographic groups. Unmarried status, low income, and rural residence were associated with a reduced likelihood of receiving standard treatment (all odds ratios [ORs] < 1, P < .05), while these factors, along with male sex, were significantly associated with worse survival outcomes (all hazard ratios [HRs] > 1, P < .05). The composite sociodemographic risk score and stratification effectively classified patients, with higher sociodemographic risk associated with reduced standard treatment access (low-risk as reference; moderate-risk: OR = 0.86, 95% confidence interval [CI], 0.82-0.90, P < .001; high-risk: OR = 0.75, 95% CI, 0.71-0.80, P < .001) and poorer survival (cancer-specific survival: low-risk as reference; moderate-risk: HR = 1.11, 95% CI, 1.08-1.13, P < .001; high-risk: HR = 1.19, 95% CI, 1.15-1.22, P < .001; overall survival: low-risk as reference; moderate-risk: HR = 1.12, 95% CI, 1.09-1.14, P < .001; high-risk: HR = 1.21, 95% CI, 1.18-1.24, P < .001). These findings were validated in an external cohort. Although overall survival improved over time, these gains were unevenly distributed across sociodemographic groups (all P for interaction < .05), with the greatest benefit in the low-risk group, modest improvement in the moderate-risk group, and no statistically significant improvement in the high-risk group, accompanied by widening survival disparities over time (all P for interaction < .05). Sociodemographic factors significantly influence treatment and survival in glioblastoma. The composite sociodemographic risk score effectively stratifies patients and identifies vulnerable populations. Notably, survival gains are uneven across sociodemographic groups, underscoring the need for targeted strategies to reduce disparities and promote equity in glioblastoma care.