Impact of Social Vulnerability and Allostatic Load on Postoperative Outcomes.

Background: We sought to investigate the association between allostatic load (AL), social vulnerability, and postoperative outcomes following hepatopancreatobiliary (HPB) cancer surgery.

Methods: Individuals who underwent HPB surgery were identified using the Epic Cosmos database. AL was calculated based on 10 biomarkers across four physiological systems: cardiovascular, metabolic, renal, and immune. Multivariable regression models were used to examine the association between AL, postoperative outcomes, and failure to rescue (FTR).

Results: Among 34,253 individuals, mean patient age was 71 years (interquartile range 63-78). Approximately half of patients were male (n = 18,045, 52.7%) and had a high Charlson Comorbidity Index (CCI) score (CCI >2; n = 29,246, 85.4%). The most common cancer site was the pancreas (n = 21,402, 62.5%), followed by the liver (n = 8451, 24.7%) and the biliary tract (n = 4400, 12.8%). Overall, 13.8% (n = 4717) of patients had high AL. On multivariable analysis, the risk of allostasis increased stepwise with higher social vulnerability (reference: low; medium: odds ratio [OR] 1.11, 95% confidence interval [CI] 1.04-1.19; high: OR 1.17, 95% CI 1.11-1.17). Moreover, high AL was associated with a 44% increased risk of Clavien-Dindo grade IV complications (OR 1.44, 95% CI 1.36-1.54) and an 85% increased risk of FTR (OR 1.85, 95% CI 1.60-2.13). In addition, the risk of 30-day mortality was approximately twofold higher with elevated AL (OR 1.92, 95% CI 1.70-2.19).

Conclusion: Individuals residing in socially vulnerable areas experience socioeconomic stressors that contribute to long-term physiological damage, resulting in worse outcomes following surgery.