Invited commentary: Mediation analysis and cancer screening, identifying areas to target to improve cancer disparities

Variation in Hospital Mortality After Complex Cancer Surgery: Patient, Volume, Hospital or Social Determinants?

INTRODUCTION

We sought to define the individual contributions of patient characteristics (PCs), hospital characteristics (HCs), case volume (CV), and social determinants of health (SDoH) on in-hospital mortality (IHM) after complex cancer surgery.

METHODS

The California Department of Health Care Access and Information database identified patients who underwent esophagectomy (ES), pneumonectomy (PN), pancreatectomy (PD), or proctectomy (PR) for a malignant diagnosis between 2010 and 2020. Multi-level multivariable regression was performed to assess the proportion of variance explained by PCs, HCs, CV and SDoH on IHM.

RESULTS

A total of 52,838 patients underwent cancer surgery (ES: n = 2,700, 5.1%; PN: n = 30,822, 58.3%; PD: n = 7530, 14.3%; PR: n = 11,786, 22.3%) across 294 hospitals. The IHM for the overall cohort was 1.7% and varied from 4.4% for ES to 0.8% for PR. On multivariable regression, PCs contributed the most to the variance in IHM (overall: 32.0%; ES: 21.6%; PN: 28.0%; PD: 20.3%; PR: 39.9%). Among the overall cohort, CV contributed 2.4%, HCs contributed 1.3%, and SDoH contributed 1.2% to the variation in IHM. CV was the second highest contributor to IHM among ES (5.3%), PN (5.3%), and PD (5.9%); however, HCs were a more important contributor among patients who underwent PR (8.0%). The unexplained variance in IHM was highest among ES (72.4%), followed by the PD (67.5%) and PN (64.6%) patient groups.

CONCLUSIONS

PCs are the greatest underlying contributor to variations in IHM following cancer surgery. These data highlight the need to focus on optimizing patients and exploring unexplained sources of IHM to improve quality of surgical care.

Association between social determinants of health and delayed postoperative adjuvant therapy among patients undergoing resection of pancreatic cancer

BACKGROUND AND OBJECTIVES

Pancreatic cancer (PDAC) requires a multimodality approach. We sought to define the association between social determinants of health (SDOH) and delayed or nonreceipt of adjuvant chemotherapy (aCT) among patients undergoing PDAC resection.

METHODS

Data on patients who underwent PDAC resection between 2014 and 2020 were identified from Medicare Standard Analytic Files and merged with the county-level social vulnerability index (SVI). Mediation analysis defined the association between SVI subthemes and aCT receipt.

RESULTS

Among 24 078 patients, 47.7% received timely aCT, 17.7% received delayed aCT, and 34.6% did not receive any aCT. High SVI was associated with delay (odds ratio [OR] 1.22, 95% confidence interval [CI] 1.10-1.34) and nonreceipt of aCT (OR 1.30, 95% CI 1.20-1.41) (both p < 0.05). 73.1% of the variation in timely aCT receipt was directly attributable to SVI, whereas 26.9% of the effect was due to indirect mediators including hospital volume (6.4%), length-of-stay (7.9%) and postoperative complications (12.6%). Socioeconomic status (delayed aCT: OR 1.25, 95% CI 1.13-1.38; nonreceipt aCT: OR 1.25, 95% CI 1.15-1.36) and household composition and disability (delayed aCT: OR 1.30, 95% CI 1.17-1.43; nonreceipt aCT: OR 1.19, 95% CI 1.09-1.29) were associated with receipt of aCT (both p < 0.001).

CONCLUSIONS

Most of the disparities in receipt of aCT after PDAC surgery are driven by underlying SDOH such as SVI.

Association Between Historical Redlining and Access to High-Volume Hospitals Among Patients Undergoing Complex Cancer Surgery in California

BACKGROUND

We sought to determine the impact of historical redlining on travel patterns and utilization of high-volume hospitals (HVHs) among patients undergoing complex cancer operations.

METHODS

The California Department of Health Care Access and Information database was utilized to identify patients who underwent esophagectomy (ES), pneumonectomy (PN), pancreatectomy (PA), or proctectomy (PR) for cancer between 2010 and 2020. Patient ZIP codes were assigned Home Owners' Loan Corporation grades (A: 'Best'; B: 'Still Desirable'; C: 'Definitely Declining'; and D: 'Hazardous/Redlined'). A clustered multivariable regression was used to assess the likelihood of patients undergoing surgery at an HVH, bypassing the nearest HVH, and total real driving time and travel distance.

RESULTS

Among 14,944 patients undergoing high-risk cancer surgery (ES: 4.7%, n = 1216; PN: 57.8%, n = 8643; PD: 14.4%, n = 2154; PR: 23.1%, n = 3452), 782 (5.2%) individuals resided in the 'Best', whereas 3393 (22.7%) individuals resided in redlined areas. Median travel distance was 7.8 miles (interquartile range [IQR] 4.1-14.4) and travel time was 16.1 min (IQR 10.7-25.8). Overall, 10,763 (ES: 17.4%; PN: 76.0%; PA: 63.5%; PR: 78.4%) patients underwent surgery at an HVH. On multivariable regression, patients residing in redlined areas were less likely to undergo surgery at an HVH (odds ratio [OR] 0.67, 95% confidence interval [CI] 0.54-0.82) and were more likely to bypass the nearest hospital (OR 1.80, 95% CI 1.44-2.46). Notably, Medicaid insurance, minority status, limited English-language proficiency, and educational level mediated the disparities in access to HVH.

CONCLUSION

Surgical disparities in access to HVH among patients from historically redlined areas are largely mediated by social determinants such as insurance and minority status.