Long-Term Particulate Matter Exposure and Prolonged Length of Stay After Surgery-A Novel Association

Air pollution negatively impacts health outcomes for chronic conditions and has been linked to the development of surgically managed diseases. Its impact on surgical outcomes, however, is not well understood.

In this cross-sectional study, we linked institutional American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) data to publicly available air pollutant data from 2006 to 2021. We compared the length of stay (LOS), 30-day complications, and readmission for patients undergoing colorectal surgery based on patient home county exposure to particulate matter <2.5 μm in diameter (PM_2.5) during the year of their operation. Patient demographics, comorbidities, procedural characteristics, as well as social vulnerability were included. Statistical analysis included chi-square tests, Kruskal-Wallis rank sum, Pearson correlation, as well as logistical and linear regression modeling.

A total of 1892 surgical encounters were linked to PM_2.5. Overall, patients were a median 58.7 years of age, 53% female, 35% Black, 45% had private insurance, and 71% came from areas with a high Social Vulnerability Index. Most procedures were elective (77%) and open (54%). The median LOS was 5 days (interquartile range, 3-9) with a 30-day readmission rate of 12% and 30% of patients experiencing at least one complication. On multivariable analysis, PM_2.5 exposure was associated with LOS. Compared to patients from areas with low PM_2.5, those from moderately elevated and high PM_2.5 had an incidence rate ratio of 1.08 [95% confidence interval: 1.04-1.13] and 1.08 [1.02-1.15], respectively.

Air pollution is associated with longer LOS following colorectal surgery. Although readmission and complication rates were not found to be statistically significant, the limited sample size warrants larger study populations.