A31-08 FIRSTLUNG L301: Baseline Socioeconomic Characteristics of a Cluster Randomized Clinical Utility Trial Evaluating Blood-based Lung Cancer Screening Across Diverse Communities

Abstract Rationale Lung cancer early detection with Low-Dose Computed Tomography (LDCT) has proven efficacy in reducing mortality; however, persistently low screening rates, driven by geographic access barriers, socioeconomic disparities and patient compliance has limited population-level benefit. The FIRSTLUNG L301 (NCT06145750) Clinical Utility Study is a prospective, cluster randomized controlled trial to assess the impact of a blood-based screening test (pWGFrag-Lung, FirstLook) on lung cancer screening utilization. A central intent of this initiative was to include patients across a wide socioeconomic range. Baseline analysis of socioeconomic data is an important component to understand the real world impact of the approach. Methods To characterize neighborhood socioeconomic demography across study practices, Area Deprivation Index (ADI) data were obtained at the census block group level (1=least disadvantaged to 100=most disadvantaged). Practice-level ADI was assigned by aggregating census block group data for patients seen at each practice site based on ZIP code catchment areas. Patient-weighted mean ADI was calculated for each practice to reflect the socioeconomic context of the population served. Practices were categorized into tertiles: least disadvantaged (ADI 1-33), middle (34-66), and most disadvantaged (67-100). Results Twenty-one practices with ADI data (98.4% patient coverage, n = 5,621) demonstrated substantial socioeconomic diversity. One practice lacked ADI data due to incomplete census mapping (89 patients, 1.6%). Census block groups within practice catchment areas ranged from ADI 4 to 99, with practice-level mean ADI ranging from 17.6 to 71.3. Patient-weighted mean ADI was 42.8 overall, with North Carolina practices at 42.1 (16 practices, 5,094 patients) and Florida practices at 49.9 (5 practices, 527 patients). Practice distribution by ADI tertile showed 8 practices (38.1%) in the least disadvantaged tertile (ADI 1-33), 11 practices (52.4%) in the middle tertile (ADI 34-66), and 2 practices (9.5%) in the most disadvantaged tertile (ADI 67-100). Notably, the practice serving the most disadvantaged catchment area (ADI 71.3) also had the largest enrollment (613 patients, 10.7% of study population). Conclusions The FIRSTLUNG L301 study successfully enrolled practices spanning a diverse socioeconomic spectrum, from affluent (ADI 17.6) to highly disadvantaged communities (ADI 71.3). With 98.4% ADI coverage and balanced representation across socioeconomic tertiles, this real-world implementation provides an appropriate context to evaluate whether blood-based screening can improve utilization across diverse populations and address barriers that disproportionately affect disadvantaged communities where the need for lung cancer screening is greatest. This abstract is funded by: Delfi Diagnostics Inc