# Associations of Social Deprivation and Oncology Physician Network Vulnerability With Acute Care Utilization in the SEER‐Medicare Population

## TL;DR

This study found that patients in socially deprived areas and regions with fewer oncologists are more likely to use emergency care after a cancer diagnosis.

## Contribution

The study introduces the concept of physician network vulnerability to understand how oncology workforce scarcity interacts with social deprivation in affecting acute care use.

## Key findings

- High social deprivation increases the probability of emergency department visits across all levels of physician network vulnerability.
- In regions with low physician network vulnerability, socially deprived patients face a higher risk of multiple emergency department visits.
- The interaction between social deprivation and physician network vulnerability had minimal impact on non-elective hospitalizations.

## Abstract

The objectives of this study were to evaluate associations of social deprivation with acute care utilization among patients with cancer, and to examine potential effect modification by physician network vulnerability.

For this retrospective cohort study, the primary exposure variable was neighborhood‐level socioeconomic disadvantage, operationalized through the social deprivation index (SDI). We assembled physician patient‐sharing networks and calculated a measure of network vulnerability for each referral region to capture specialist scarcity. The two outcomes of interest were counts of emergency department (ED) visits and non‐elective hospitalizations during the 12 months following cancer diagnosis. We conducted hurdle regressions, with logistic and negative binomial mixed‐effects models for the zero and positive, non‐zero parts of the outcome distribution, respectively, and stratified by physician network vulnerability.

We analyzed 2016–2020 Surveillance, Epidemiology, and End Results (SEER)‐Medicare linked data for Medicare beneficiaries diagnosed with breast, colorectal, or lung cancer.

The study cohort comprised 47,756 patients with breast, colorectal or lung cancer. Patients in high SDI neighborhoods (vs. low) had a higher probability of at least one ED visit across all physician network vulnerability strata (low network vulnerability—average marginal effect (AME) [95% CI]: 0.03 [0.01–0.05]; medium network vulnerability—AME [95% CI]: 0.03 [0.01–0.04]; high network vulnerability—AME [95% CI]: 0.05 [0.02–0.08]). Conditional on at least one ED visit, patients in high SDI neighborhoods (vs. low) had a greater relative risk of additional ED visits when their region was characterized by low physician network vulnerability (RR [95% CI]: 1.25 [1.09–1.43]).

Our findings suggest that SDI and physician network vulnerability interact to increase the probability and likelihood of ED visits, but the interaction was minimal for non‐elective hospitalizations. More research is needed to better understand how social drivers of health and oncology workforce scarcity affect care utilization and outcomes in patients with cancer.