2.1. Research Subjects and Sampling Method
461 subjected were firstly included in this study from 23 March to 12 April 2020[1], the Snowball Sampling method (recruit subjects from among acquaintances) was used to collect the data from 180 Chinese college subjects (undergraduate and graduate students) studying in South Korea during March 23-April 8, 2020 and 281 Chinese college subjects (undergraduate and graduate students) studying in China during April 2-12, 2020. In line with the research aim, which was to survey college students, the samples of those who stated "Employed", "Unemployed" and "Others" in the occupation question were removed, leaving a total of 420 students (171 in South Korea, named as “International Group”, and 249 in China, named as “Mainland Group”). All subjects expressed to a willingness to participate and understand the background and purpose of the study.
2.2. Data Collection Tools
The online questionnaire surveys were distributed using the Naver Online Survey (Tool) for International Group and Wejuanxing Online Survey (Tool) for Mainland Group respectively. The questionnaires for the two groups were at the same design and written in Simplified Chinese Characters. During the initial screening of the online questionnaire, the purpose of the research, and the confidentiality and privacy of individuals was ensured in written format on the first page of the survey questionnaire. Only after reading and clicking “AGREE” to make the consent, the filling of the questionnaire could begin. Before conducting the survey, we did the revision and verification of the contents of the questionnaire through the online pilot survey and to make sure that the statements are appropriate and understandable.
2.3. Research Tools
This study was conducted by 1) YGHC COVID-19 Online Survey Tool and 2) Patient Health Questionnaire-9. YGHC COVID-19 Online Survey Tool was designed and updated by Yonsei Global Health Center (YGHC), aiming to evaluate the target participants’ basic demographics characteristics, knowledge about COVID-19, preventive practices against COVID-19, depressive symptoms. Questions in the YGHC COVID-19 Online Survey Tool were found to own a reasonable validity and reliability in Wang’s research on Chinese general population [15]. YGHC made changes on the Part E (Precaution measures) and Part F (Additional information) according to the specific situation in the two countries. The Patient Health Questionnaire-9 (PHQ-9) was added to the study to provide a baseline for the incidence of depression.
2.4. Variables Description
2.4.1. General Demographics Data
In this study, to reflect the demographic characteristics of the respondents, the basic survey asked questions related to: “sex”, “age”, “education level”, “marital status”, “family size”, “whether you had traveled abroad in the past 14 days”, “whether you had chronic diseases”, and “whether you had experienced quarantine”. The educational level was divided into “Undergraduate” and “Graduate”, and the marriage status comprised of “Single” and “Married”. Family size includes “1-person family”, “2-person family”, “3~5 persons family” and “more than 6-member family”. The question about traveling overseas in the past 14 days, having basic chronic and quarantine had two possible answers: "no" and "yes". A question about the self-assessed physical condition was also included.
2.4.2. Knowledge about COVID-19
Understanding and perception of COVID-19 and other topics were assigned in a self-enumeration questionnaire, including knowledge on transmission pathway, source of related information, degree of concern, etc.
2.4.3. Preventive practices of COVID-19
Nine basic preventive practices were incorporated into the questionnaire. We gave the score corresponding to the degree to which a measure was practiced on a daily basis (1 = Never do this and 5 = Do this every day) and added total points to all the questions to calculate the total preventive practices. Cronbach's Alpha coefficient of preventive practices of the COVID-19 scale was 0.78.
2.4.4. Patient Health Questionnaire-9
Depressive symptoms could be diagnosed based on the 9 criteria for depression in the Diagnostic and Statistical Manual of Mental Disorders published by the American Psychiatric Association [30]. To understand the response to these question, each question was divided into 4 categories: "not at all (0 points), "several days "(1 point), "more than held the days" (2 points), and "almost every day" (3 points) [31]. According to the scoring criteria, the score on PHQ-9 was divided into five groups: 0–4, 5–9, 10–14, 15–19, 20–27, which corresponded to "minimal or none," "mild," "moderate," "moderately severe," and "severe" depression, respectively [32]. The higher the score, the more intense the level of depression.
In this study, for ease of comparison, the symptoms of depression were assessed based on depression scores from individual respondents according to the classification methods of "Ten-point hierarchies (a score of 10 points or above indicated mild depression [33])." Cronbach's Alpha coefficient of the scale in this study was 0.89.
2.5. Statistical Analysis Approach
In this study, STATA 15·0 and SPSS 24·0 were used to conduct statistical analysis. The specific analytical methods are as follows:
(1)Firstly, descriptive statistics were calculated for demographic characteristics, knowledge, and concern about the COVID-19, and Chi-squared tests were performed in each variable between ‘International Group’ and ‘Mainland Group’.
(2)Secondly, an independent t-test was carried out to compare the differences between ‘International Group’ and ‘Mainland Group’ in COVID-19 prevention practice.
(3) Thirdly, a Chi-squared test was conducted to compare the different levels of depression between the two groups.
(4) Lastly, to explore the determinants of the different depression levels, hierarchical regression was performed.
Footnote:
[1] From WHO, date as of 31 March 2020: China: Total confirmed cases 82,545, total deaths 3314; Korea: Total confirmed cases 9,786, total death 162