Social Vulnerability Index Is Associated with Time-to-Treatment in Resectable Non-Small Cell Lung Cancer

A. A. Khan, S. K. Shah, G. C. Alex, N. M. Geissen, M. J. Liptay, C. W. Seder
Rush University Medical Center, Chicago, Illinois

Purpose: Social determinants of health (SDoH), including race, education, and insurance status, have been linked to delays in treatment of non-small cell lung cancer (NSCLC) patients, however this has been difficult to quantify. We investigated if social vulnerability index (SVI), a quantitative measure of SDoH, is associated with time-to-treatment.

Methods: The study population consisted of patients with surgically resected NSCLC at a single institution between 2010-2021. Non-Illinois residents, patients with an incomplete address, or patients that received neoadjuvant therapy were excluded. Time-to-treatment was defined as the time from the chest CT scan that prompted surgical intervention to the date of surgery. SVI was determined by geocoding the permanent addresses of Illinois residents, mapping them to US census tracts, and using the Centers for Disease Control and Prevention calculator for census-tract level SVI. Each tract is assigned an SVI ranging from 0 to 1, based on 14 social factors grouped into four themes: socioeconomic status, household composition and disability, minority status and language, and housing and transportation. Univariate and multivariate linear regressions were used to examine the association between SVI and time to treatment, adjusting for patient demographics and comorbidities.

Results: Overall, 962 patients met inclusion criteria, of whom 55% (532/962) identified as female and 78% (755/962) identified as white. The median age was 71 years (IQR 64-76) and 47% (451/962) had private insurance. The median SVI was 0.31 (IQR 0.15-0.60) and the median time-to-treatment was 34 days (IQR 22-57). On univariate analysis, higher SVI, black race, Medicaid insurance, uninsured status, and diabetes were associated with increased time-to-treatment (β=47.96, 95% CI 41.18,54.74, p< 0.001; β=21.05, 95% CI 15.22,26.88, p< 0.001; β=33.89, 95% CI 17.08,50.69, p< 0.001; β=36.49, 95% CI 4.34,68.63, p=0.026; β=43.83, 95% CI 41.65,46.19, p=0.005, respectively.) On multivariate analysis, higher SVI, Medicaid insurance, and uninsured status were independently associated with increased time-to-treatment (β=46.13, 95% CI 38.24,54.02, p< 0.001; β=22.97, 95% CI 7.10,38.84, p=0.005; β=34.02, 95% CI 4.28,63.75, p=0.025, respectively), while Asian race and higher ECOG score were associated with decreased time-to-treatment (β=-13.97, 95% CI -26.41,-1.53, p=0.028; β =-4.48, 95% CI -8.49,-0.48, p=0.029, respectively). For every increase of 0.1 units in SVI, an increase in time-to-treatment of 4.6 days was observed.

Conclusion: Higher SVI, Medicaid coverage, and uninsured status are associated with increased time-to-treatment in resectable NSCLC. This study highlights the importance of SVI as a tool to help identify high-risk patients for delays in treatment. With further validation, SVI may help surgeons to provide more equitable care.

Identify the source of the funding for this research project: Departmental Funding