Healthcare utilization of lung cancer patients associated with exposure to fine particulate matter: A Korean cohort study

Background: Higher concentrations of particulate matter (PM) have been shown to cause deterioration of the symptoms of respiratory and cardiovascular disease in several regional studies. Here, we aimed to investigate the healthcare utilization of lung cancer patients associated with short-term exposure to PM at the national level in Korea. Methods: We extracted the data of 210 558 subjects over a period of 3 years (2015-2017), who were diagnosed with lung cancer before 2015 and benefited from the National Health Insurance Sharing Service. We performed the interpolation method using the geographic information system to calculate the estimated mean PM2.5 and PM10 concentrations by regions and classified three groups as high (upper 10%), intermediate (10%-90%), and low (bottom 10%) based on the mean PM mass concentrations of the month. Results: The monthly average number of outpatient visits was significantly increased in high PM2.5 urban areas (46.296 vs. 50.646, p = 0.015). In high PM2.5 nationwide regions, the monthly average number of emergency admission was significantly increased (0.528 vs. 0.785, p = 0.001). The outpatient visits tended to change with PM2.5 concentration and correlated with PM10/PM2.5 concentrations in urban and nationwide areas. In high PM2.5 urban regions, there was a significant increase in bronchodilator prescriptions (3.102 vs. 3.758, p = 0.008). Concerning high PM2.5 nationwide regions, there were significantly increased prescriptions of antibiotics, steroids, bronchodilators, antihistamines, and mucolytics. Conclusions: This study suggests that exposure to PM2.5 is significantly associated with hospital utilization and drug prescription in lung cancer patients.