Changes in mental well-being during the COVID-19 pandemic: A longitudinal study among Danes from 2019 to 2021.

Numerous studies have shown that the COVID-19 pandemic had large influence on mental health during the first lockdown, but fewer studies have focused on the long-term influence on mental health. In a national longitudinal study, we examined mental well-being measured just before (fall 2019) and twice during (falls of 2020 and 2021) the COVID-19 pandemic. We utilized the Danish Health and Wellbeing Survey with questionnaires collected in 2019, 2020 and 2021 among the same study population consisting of 8179 persons. The outcome was mental well-being measured by the Short Warwick-Edinburgh Mental Well-Being Scale (SWEMWBS). Linear regression models were conducted to evaluate change in SWEMWBS from 2019 to 2021. The SWEMWBS distribution was similar in 2019, 2020 and 2021, although the distribution moved to lower scores in 2020 compared to 2019 and moved slightly to higher scores in 2021 compared to 2020. Mean SWEMWBS decreased from 24.8 (95%CI 24.7-25.0) in 2019 to 24.1 (24.0-24.2) in 2020 and increased to 24.4 (24.3-24.6) in 2021 (p < 0.001). The mean decrease from 2019 to 2020 and increase from 2020 to 2021 was strongest among women, persons below age 75 years, persons without depression and among persons with higher education and with employment. In conclusion, we find that mental well-being decreased from 2019 to 2020 and slightly increased from 2020 to 2021 without reaching the pre-pandemic level. These changes are statistically significant but small and support that COVID-19 may only have had a small long-term influence on mental health in the general population.

The Danish Health and Wellbeing Survey: Study design, response proportion and respondent characteristics.

AIMS: This study aimed to describe the study design and respondent characteristics (including non-response analyses) of the Danish Health and Wellbeing Surveys in 2015 and 2019 and a follow-up survey that was carried out during the COVID-19 pandemic in 2020. METHODS: The Danish Health and Wellbeing Survey is the Danish part of the European Health Interview Survey (EHIS). The samples in 2015 (N=12,000) and 2019 (N=14,000) were both based on a simple random selection of individuals aged ⩾15 years from the Danish Civil Registration System. All individuals from the sample in 2019 who were still alive and living in Denmark were reinvited for a follow-up survey in 2020 (N=13,474). Data in all surveys were collected via self-administered questionnaires (web or paper based). The questionnaires in 2015 and 2019 included the EHIS model questionnaire as well as national questions, whereas the questionnaire in 2020 mainly focused on physical and mental health, employment and working lives, and health behaviour. RESULTS: The overall response proportion declined slightly between 2015 (48.4%) and 2019 (47.4%) but went up to 49.8% in the follow-up survey in 2020. Unit non-response was associated with, for example, male sex, younger age, being unmarried and lower educational level but not with degree of urbanisation. In all, 5000 individuals completed the questionnaire in both 2019 and 2020. CONCLUSIONS: The results are in line with most previous research on non-response in health surveys. However, an association between degree of urbanisation and non-response has been suggested in previous studies. This association was not found in our study.