Impact of COVID-19 pandemic on critically ill patients with colon cancer: A population-level study.

297 Background: The COVID-19 pandemic strained healthcare systems and disrupted pre-pandemic levels and trends in the short-term mortality of colon cancer hospitalizations. Colon cancer is the fourth most diagnosed cancer in the US and Texas. The impact on short term mortality in Texas in the years since the COVID-19 pandemic have not been explored. Methods: We used publicly available, deidentified, and state-wide data to conduct a population-base cohort study of hospitalizations aged ≥ 18 years admitted to intensive care units at acute care hospitals in Texas during 2016-2022 with a diagnosis of colon cancer. Hospitalizations transferred to another acute care hospital were excluded from the study. Colon cancer was identified using ICD-10-CM codes C18x and C20 selected from Clinical Classification Software Refined category NEO015: Gastrointestinal cancers - colorectal. Short-term mortality was defined as in-hospital mortality or discharge to a hospice. The response variables are pre-pandemic time trend, level change, change in time trend, and final time trend. The primary analysis method was interrupted time series analysis (ITSA) based on multilevel-multivariable logistic regression with results reported as average marginal effects per quarter (AME) and 95% confidence intervals (95% CI) in changes to the absolute probability of mortality. The matched pairs t-test was applied to ITSA and counterfactual predicted probabilities to further elucidate the impact of the COVID-19 pandemic. Sensitivity analyses was performed for hospitalizations aged ≥ 65 years and for hospitalizations without a diagnosis of COVID-19. Results: A total of 49,007 hospitalizations were included in the study of which 21,995 (44.9%) occurred after the beginning of the pandemic. Unadjusted short-term mortality was lower in the pre-pandemic period compared to the post-pandemic period (18.1% vs 20.1%). On adjusted analysis, the post-pandemic period remained associated with higher mortality rates. The pre-pandemic short-term mortality time trend was negative (AME -0.19%/quarter, 95% CI [-0.28% to -0.10%], p = 0.0001). The change in time trend was positive (AME 0.39%/quarter, 95% CI [0.23% to 0.55%], p < 0.0001) and the change in level was also positive (AME 1.25%, 95% CI [0.0.04% to 2.47%], p = 0.0436). The final time trend was significant and positive (AME 0.20%/quarter, 95% CI [0.07% to 0.33%], p = 0.0023). The point estimate and 95% CI for the difference between ITSA predicted and counterfactual predicted probabilities of mortality was 3.45% (3.41% to 3.48%). Similar results were observed on sensitivity analyses. Conclusions: Since the onset of the pandemic there was a 2% increase in the absolute probability of short-term mortality and a change from negative to positive time trend in short-term mortality. The average impact of the COVID-19 pandemic on the absolute probability of short-term mortality is estimated at over 3%.