Whether university teaching on campus with infection control measures in place is associated with higher risk of COVID-19 than online instruction, is unknown. The investigators will assess this by conducting repeated surveys among students at universities and university colleges in Norway, where some instruction is given in-person, and some is provided online (hybrid model). The investigators will ask about the students' COVID-19 status, and how much in-person and online instruction the students are getting. The investigators will estimate the association between in-person instruction and COVID-19-risk using multivariate regression, controlling for likely confounders. The investigators will also assess whether type of instruction is associated with how satisfied the students are with the instruction the students are offered, their quality of life, and learning outcomes.

The investigators are inviting all universities and university colleges in Norway to take part. All students at institutions that agree to participate will receive an SMS (alternatively an e-mail) inviting them to take part in the study. The invitation includes a link that directs participants to a web-based informed consent-form and questionnaire. The investigators will use the University of Oslo's solutions for online consent form, web-based survey (Nettskjema), and secure storage of research data (TSD).

The investigators will ask the participants if the participants have been tested for COVID-19, the results of such a test, how much in-person instruction the students have been offered, and how much online instruction the students have been offered. The investigators will also inquire about other risk factors for COVID-19 and background variables that may be included as potential adjustment factors (confounders) in the analyses (see Attachment 1 - Questionnaire).

The investigators will survey the students every two weeks by new invitations by SMS or e-mail. The study period will last as long as the universities maintain their arrangement with in-person instruction for only select groups of students. The investigators plan for a study period that lasts for the remainder of 2020. The investigators will ask for the participants consent to link the survey results to information on study programme, basis for admission, study status, academic results, sex and age from the Common Student System.

The investigators will run multivariate regressions to test whether there is an association between in-person instruction and the outcomes.

In-person instruction is a continuous variable, defined as

(Number of days offered in-person instruction) / (Number of days offered in-person instruction + Number of days offered online instruction)

The investigators will control for potentially confounding variables, including year of study program, field of study, age, and gender. The investigators plan for separate analyses for each participating university/university college, and a pooled analysis across institutions.

Inclusion Criteria:

• Student in first, second, or third year at university or university college
• Agrees to participate (signed consent form)

Exclusion Criteria:

-

All university of university college students who agree to participate.

We plan to make the full data set publicly available, after ensuring the re-identification of individuals is not possible.

From spring 2021 and for at least 5 years.