INTRODUCTION: COVID-19 has disrupted normal life and resulted in an online transformation of teaching. Little is known about how these changes affected academic stress in students. This study examined the role of changes of teaching methods on academic stress among university students during the first lockdown in Denmark.

METHODS: The cross-sectional survey was part of the international "COVID-19 International Student Well-being Study" and included responses on socio-economic characteristics, infection worries, academic stress, work capacity and satisfaction with teaching from 1,541 Danish health and medical science university students in May-June 2020. Changes in academic stress were analysed using descriptive statistics and multi-variable analyses using stepwise logistic regression.

RESULTS: A considerable part (39%) of students reported academic stress due to COVID-19. One third reported that their study workload had increased significantly due to the COVID-19 outbreak and that they were concerned about their ability to complete the academic year. Factors associated with academic stress were female sex, young age, bachelor level, knowing a COVID-19 patient and being worried about becoming infected, whereas immigration background, sufficient financial resources and living arrangements were not.

CONCLUSIONS: Our findings suggest that the COVID-19 outbreak has influenced university students' academic stress. It is important to set up structures to support students' mental health and educational trajectory during the pandemic.