E-cigarette-associated Severe Pneumonia in Korea Using Data Linkage between the Korea National health and Nutrition Examination Survey (KNhaNES, 2013-2019) and the National health Insurance Service (NhIS) Claims Database.

Introduction:
This text provides an analysis of the association between e-cigarette use and the development of acute severe pneumonia in the Korean population using a national database. The study aimed to investigate the incidence of severe pneumonia requiring hospital admission according to e-cigarette use and the secondary endpoints of in-hospital mortality, intensive care unit admission, ventilator care, and hospital stay in days.

Key Points:

* The study included 28,950 individuals, of which 578 (2.0%) were e-cigarette users.
* EC users were younger, more often male, had higher levels of education and household income, and had fewer comorbidities than non-EC users.
* Severe pneumonia was noted in 37 of 28,372 non-EC users (0.13%), but there were no occurrences of severe pneumonia in EC users.
* The incidence of pneumonia occurrence was not different between the two groups (P = 1.000).
* The study suggests that there might be no EVaLI patients in Korea during the investigation period.
* The study design includes a retrospective analysis using linkage of data between the Korean National health and Nutrition Examination Survey (KNhaNES) and the National health Insurance Service (NhIS) administrative claims database.
* The primary endpoint of the study was the development of severe pneumonia requiring hospital admission according to e-cigarette use.
* The secondary endpoints were in-hospital mortality, intensive care unit admission, ventilator care, and hospital stay in days.
* The study also aimed to investigate the incidence of pneumonia occurrence between the two groups.

Main Message:
The main message of the text is that there is no association between e-cigarette use and the development of acute severe pneumonia in the Korean population. The study suggests that the lack of severe pneumonia cases among e-cigarette users may be due to differences in composition and content of harmful ingredients in e-cigarettes in Korea compared to the US. however, the study also emphasizes the need for a large-scale prospective study to evaluate the effect of e-cigarette use on development of acute lung injury, as the popularity of e-cigarettes is increasing. additionally, the study highlights the importance of monitoring the hazards of e-cigarettes by the government, as the number of e-cigarette users is small and the baseline characteristics of e-cigarette users, including age, comorbidities, and socio-economic status, can affect the occurrence of pneumonia.

Kang hS, Kim JY, Park hJ, et al. E-cigarette-associated Severe Pneumonia in Korea Using Data Linkage between the Korea National health and Nutrition Examination Survey (KNhaNES, 2013-2019) and the National health Insurance Service (NhIS) Claims Database. J Korean Med Sci. 2021;36:e331. doi:10.3346/jkms.2021.36.e331