Sepsis risk factors and associated mortality in elderly mesothelioma patients with malignant pleural effusion.

e20063 Background: Age is an independent prognostic factor worse outcomes in mesothelioma patients. A significant proportion of sepsis related hospitalizations involve cancer patients, with sepsis playing a major role in cancer mortality and morbidity. However, specific data in elderly mesothelioma patients are limited. Our study seeks to identify determinants, trends and clinical profile and mortality outcomes of mesothelioma patients admitted with malignant pleural effusion. Methods: We used the 2016-2022 National Inpatient Sample to estimate the events of sepsis among elderly patients (ages 60 and older) with mesothelioma who were admitted with malignant pleural effusion. Multivariable regression models were adopted to identify independent predictors, and the overall mortality risks estimated. The data accounted for the weight, strata, and cluster for national estimates. Results: Among 4,395 elderly patients with mesothelioma and malignant pleural effusion, 325 (7.39%) developed sepsis during hospitalization. In multivariable analysis, independent predictors of sepsis included palliative care (AOR 3.53, 95% CI 1.81-6.89, p<0.001), metastatic cancer (AOR 2.05, 95% CI 1.07-3.90, p=0.030), Hispanic ethnicity (AOR 3.38, 95% CI 1.21-9.47, p=0.021), and self-pay insurance status (AOR 9.79, 95% CI 1.24-77.11, p=0.030). Temporal trends showed increasing sepsis risk in recent years, with significantly higher odds in 2020 (AOR 4.27, p=0.035) and 2022 (AOR 6.56, p=0.006) compared to 2016. Traditional comorbidities including diabetes, chronic kidney disease, hypertension, congestive heart failure, and COPD were not independently associated with sepsis risk. Age, sex, hospital teaching status, geographic region, and socioeconomic status (by ZIP code income quartile) were also not significant predictors. Patients with sepsis experienced dramatically higher in-hospital mortality compared to those without sepsis (30.77% vs. 4.79%, p<0.001). After adjusting for confounders, sepsis remained independently associated with a 7.6-fold increased odds of in-hospital death (AOR 7.58, 95% CI 2.78-20.67, p<0.001). Conclusions: Although only a minority of the elderly mesothelioma patients with malignant pleural effusion incurred sepsis, it was associated with more than 7 fold higher odds of inpatient mortality. Sepsis risk was more profoundly driven by factors suggestive of advanced stage of cancer. These findings underscore the need for equitable care especially for those with late stage illness, marginalized insurance or ethnic backgrounds.