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Sampling Procedure
| The C19 ISWS applied a stratified convenience sampling design. In a first step, HEIs were selected within countries, covering western (Belgium, France, Germany, the Netherlands, Swiss, the UK), Central-Eastern (Czech Republic, Slovakia), eastern (Romania, Hungary, the Russian Federation), northern (Sweden, Finland, Norway, Iceland, Denmark), and southern (Spain, Italy, Portugal, Greece, Cyprus) European countries and including some additional high-, and upper-middle-income countries (Canada, Israel, South Africa, Turkey, and the USA). A selection of various HEIs within the same country was preferred, to achieve variation in the types of HEI within the countries as well. These partners were initially selected from scientific organizations of which the coordinating team is a member (e.g., the European Society of Health and Medical Sociology), or from previous scientific collaborations with members of the coordinating team (e.g., the SNIPE project). Partners were sent a concise study protocol, which included the main research aims, sampling methodology, and plan of analysis, as well as requisites for participation in the study and publication guidelines. Only a small number of partners declined this initial invitation, mostly owing to lack of time (fewer than 10 HEIs) or to a delay in acquiring institutional review board (IRB) approval (three HEIs from the UK). Several partners contacted other HEIs within or outside their own countries through their own scientific networks, to increase the sample size. This resulted in a sample size of 110 HEIs. The sampling of HEIs was initially aimed at obtaining a sufficient sample of institutions that would allow multilevel modeling. While the initial sampling of HEIs was not aimed at the European continent, in later stages of the recruitment, we restricted the participation of HEIs to Europe in order to obtain a sample that was comparable in terms of timing of the epidemic, as well as in terms of the cultural and political context. Within each HEI, a consortium partner was appointed, who was responsible for the distribution of the survey within his or her own HEI. In a few countries, partners additionally recruited participants from outside their own HEI through social media platforms or their professional networks. In Finland, a central research institution distributed the survey across all Finnish HEIs. A joint controller or data-sharing agreement was signed by each participating HEI or research institution, and IRB approval was obtained prior to launching the survey. The HEI partners distributed the survey link by e-mail to all students within their HEI. First, an invitation e-mail was sent, which included a link to an online website that covered relevant information concerning the study and protection of the participant’s privacy (see Supplemental material, Table 1A). After one week, a reminder e-mail was sent. Alternative recruitment methods were the use of newsletters, student-specific platforms, and social media platforms. Sampling participants through the internet was preferred as this allowed people to participate anonymously and with little effort. In addition, it is one of the only possible methods of data collection in times of quarantine. Data collection took place between 27 April, 2020, and 7 July, 2020, with two-thirds of HEIs collecting the data within the first month of the initial launch. Within each HEI, the survey was active for 2 weeks. The HEIs had the opportunity to prolong this period by one or a maximum of two weeks if the response rate initially remained low. This prolongation allowed several HEIs to set up additional attempts to increase the response rate (such as adding additional communication channels, sending out a new reminder, involving more HEIs). Inclusion criteria were: (1) being enrolled at a HEI, and (2) being 18 years or above. HEI students at bachelor’s, master’s, and Ph.D. levels were included, as well as international or exchange students. A target was set to recruit at least 10% of the student population of each participating HEI. The count of respondents by HEI and country is provided in the Supplemental material, Table 1B. In each HEI where the study was implemented, the local partner was required to check the IRB guidelines and, if this was necessary, to seek approval of the appropriate ethics committee or review board. The multicountry research design was approved by the Ethics Committee for the Social Sciences and Humanities of the University of Antwerp, as well as by the Ethics Committee for the Social Sciences of Ghent University. Before starting the survey, each participant was asked to read an informed consent form and indicate consent by checking a box. |
