The HOUSES index: A novel, patient-level measure of socioeconomic status linking real-world housing data to overall survival in metastatic pancreatic ductal adenocarcinoma.

Abstract

e13719 Background: Previous research has demonstrated disparities in survival outcomes for patients with pancreatic ductal adenocarcinoma (PDAC), related to social determinants of health (SDoH). A major limitation of cancer disparities research is the reliance on census-level measures of socioeconomic status (SES). These measures ignore individual-level variability within the same zip code, risking ecological fallacy and limiting clinical applicability. In contrast, the Housing-Based Socioeconomic Status (HOUSES) index is a patient-level validated measurement of SES. This study aims to assess the relationship of HOUSES with overall survival (OS) amongst patients with metastatic pancreatic ductal adenocarcinoma (mPDAC). Methods: We retrospectively identified 189 patients with a diagnosis of mPDAC between 2019-2024 from the institutional database of a high-volume academic center. Supplemental data was abstracted from the electronic medical record (EMR). The HOUSES index was calculated using each patient’s home address at the time of diagnosis to geocode housing characteristics obtained from government assessor offices. These housing features include assessed value, square footage, and number of bedrooms and bathrooms. OS was defined as the time between diagnosis and the date of death or last follow up on 1/1/2026. A multivariable Cox model was performed adjusting for age, sex, tobacco use, ECOG performance status, income, insurance, cancer treatment, national-percentile area deprivation index, and rural-urban residence. Results: Of the 189 patients, the median age was 67 (IQR 58-73), 52.9% were male, and 92.1% were self-identified non-Hispanic white. The median OS was 10.3 months (IQR 4.9-22.9), and 85.3% received cancer directed treatment. Compared to the lowest SES Q1, higher HOUSES quartiles had significantly lower hazard ratios (HR), HOUSES Q2 (HR: 0.58 [95%-CI: 0.39–0.85]), Q3 (HR: 0.51 [95%-CI: 0.35–0.75]), and Q4 (HR: 0.64 [95%-CI: 0.45–0.89]), demonstrating a protective effect on OS. Other factors independently associated with OS included Medicare compared to commercial insurance (HR: 0.18 [95%-CI: 0.10–0.32]), age (HR: 1.04 [95%-CI: 1.02–1.06]), and ECOG performance status (HR: 2.14 [95%-CI: 1.31–3.50]). Conclusions: Our study demonstrates that mPDAC patients in higher SES quartiles of the HOUSES index have a longer OS when compared to the most disadvantaged quartile. These trends exist while controlling for other SDoH variables, demonstrating that HOUSES provides additional information on patient SES and health barriers. Overall, these results demonstrate the potential of HOUSES as a novel, patient-level sensitive measure of SDoH that can be valuable for both cancer research, and in clinical practice as a method to identify patients in need for further support.