1. Search for publications in English
We performed online searches with keywords: North Korea, Democratic People’s Republic of Korea, smoking, tobacco. Inclusion and exclusion criteria are as follows:
Inclusion criteria: a) a full text article in a peer review journal, and b) a publication from an organization containing data and information regarding tobacco use and control in the DPRK.
Exclusion criteria: a) an article in a newspaper or a personal blog, b) a review article, c) an article of which study subjects were not residing in the DPRK, and d) an article of which full text is not available.
The articles and publications that met requirements of the inclusion criteria were kept for review.
2. Search for the DPRK publications in Korean
The Information Center on North Korea, an institution under the Ministry of Unification, Republic of Korea (South Korea) maintains multiple periodic DPRK journals. The list of the journals and titles of articles, mostly in Korean, are available on the center’s website. It is noteworthy that all the authors are fluent in both Korean and English. Looking at the themes of the journals, two of them, “조선의학 (Chosun Medicine)” and “예방의학 (Preventive Medicine)”, were selected for further search. To find the recent materials and due to limited availability, the search was narrowed down to those published from 2009 to 2018. All the titles of articles published in the journals were reviewed online and the relevant articles were selected. The definition of the relevant article here is that its title included the Korean word that corresponded to “tobacco”, “smoking cigarette”, or “smoking cessation” in English. One of the authors visited the center to make copies of the full text for further analysis. The articles that were related to the research questions were kept for review. We did not strictly apply the inclusion and exclusion criteria above for this category to collect as many materials directly from the DPRK as possible.
3. Search for online media in Korean created by the DPRK
We found several media websites operated by the DPRK government: uriminzokkiri.com, dprktoday.com, and dprkmedia.net. Using the keywords in Korean that corresponded to “tobacco”, “smoking cigarette”, “smoking cessation” in English, we found multiple web articles and videos that were related to the study questions. They were saved in a local computer for review.
4. Search for other materials
We performed online search to find any other materials that were relevant to the research questions. When the acceptable material was found, it was saved in a local computer for review.
We began the searches on April 04, 2021 and completed on May 07, 2021. After collecting all available materials as above, we reviewed the contents to answer the research questions.