Health-related quality of life before and during the COVID-19 pandemic in Switzerland: a cross-sectional study

The CoWELL sample consisted of 1581 individuals who provided data on HRQOL (76% women, mean age = 43 years (SD = 14 years); Tables 1 and 2, Figure S1). Most participants had a university education (61%) and were employed or in education at time of the survey (88%). Mean time since introduction of restrictive measures in Switzerland (16 March 2020) was 59 days (SD = 9 days).

The SGP sample included 1209 participants (58% women, mean age = 49 years (SD = 15 years); Table 1). More than half (54%) had compulsory education or vocational training as their highest education, and one quarter (24%) had a university education. The majority (72%) were employed or in education at time of the survey.

Overall, adjusted for sex, age, and education, physical HRQOL was better (PCS, + 5.8, p < 0.001) and mental HRQOL was worse (MCS, -6.9, p < 0.001) in the CoWELL sample compared to the SGP sample (Fig. 1 and Table S1). More specifically, we found better physical functioning, less bodily pain, and more favourable general health perceptions in the CoWELL sample than in the SGP sample. Social role functioning, emotional role functioning, and mental health were lower in the CoWELL sample than in the SGP sample. Differences between the CoWELL and the SGP sample were particularly high for mental health (MH, −9.9), bodily pain (BP, 4.5), and overall physical and mental HRQOL (PCS, 5.8, and MCS, −6.9), by far exceeding the thresholds for minimally important differences [41].

Figure 1 depicts the differences in physical and mental HRQOL and the eight health domain scales between participants from the CoWELL sample (during the pandemic; n = 1581) and the Swiss general population (before the pandemic; n = 1209) adjusted for sex, age, and education; positive values indicate better HRQOL and negative values indicate poorer HRQOL during compared to before the COVID-19 pandemic.

Physical HRQOL: In the CoWELL sample, persons who responded longer after the start of restrictive measures reported lower physical HRQOL compared to those having responded more closely to the implementation of measures (p = 0.002; Fig. 2, Table S2). Persons with better health literacy reported higher physical HRQOL (p < 0.001). Persons who were neither employed nor in education reported lower physical HRQOL compared to persons being employed or in education (p < 0.001). Physical HRQOL was also lower in persons in (self-)isolation at time of survey (p = 0.020), in those at risk to develop severe COVID-19 (p < 0.001), and in those perceiving to already have had COVID-19 (p < 0.001). Physical HRQOL was better in those who did not need a person to ask for support (p = 0.003).

Mental HRQOL: Older persons (p < 0.001) and persons with better health literacy (p < 0.001) reported higher mental HRQOL (Fig. 3, Table S3). Mental HRQOL was lower in women (p = 0.026), in those with compulsory education/vocational training or with university education compared to those with upper secondary education (p = 0.038), in French or Italian speaking persons compared to German speaking persons (p < 0.001), and in those living alone, or with their parents and/or children compared to those living only with a partner (p < 0.001). Persons reporting not having enough contact with family and friends (p < 0.001), not having someone they could ask for support (p < 0.001), and those perceiving to already have had COVID-19 (p = 0.007) reported lower mental HRQOL.

Our study showed that, in Switzerland, physical HRQOL was better in this first phase of the pandemic than before the pandemic. This contrasts with a Japanese study using a representative sample, where physical HRQOL was lower one year after the start of the COVID-19 pandemic [38]. Public health protective measures were different between Switzerland and Japan, and in the Japanese study, more time had passed since the first lockdown than in our study. In Switzerland, individuals were allowed to go outdoors even during periods with strict protective measures. People might have spent their time in the nature doing physical activity as a compensation. Increased physical activity during the early period of the pandemic was associated with improved physical health [54, 55]. Higher perceived physical HRQOL during the first phase of the pandemic might also be due to the comparison of oneself with news reports and pictures of people who were suffering and dying from COVID in the news. This downward comparison might have made individuals feeling better in terms of their own physical health [56]. We also observed that physical HRQOL decreased with more time passed since the implementation of pandemic measures in Switzerland. Discontinuation of commuting to the office and thus increased sedentary behaviour over time could be one reason [57], but also the lack of ergonomic work environments at home might have caused health issues such as back pain [58‐60]. We found that individuals who were in isolation at time of the survey or who have already had COVID-19 were at risk for low physical HRQOL, likely because staying at home and the impact being/having been sick with COVID-19 prevented them from physical activity. Individuals at risk for severe course of COVID-19 had lower physical HRQOL than those who had no elevated risk for severe COVID-19. Most of them reported either obesity, cardiovascular health problems, lung diseases or other chronic diseases, which may generally limit their ability to engage in physical activity.

Mental HRQOL was lower during the pandemic than before. This was also observed in Austria [32], in the US [37], and in Japan [38]. The Swiss Corona Stress Study reported increased stress levels during the pandemic and a higher prevalence of depressive symptoms [61]. A systematic review found the lowest point for anxiety and depression after 60 days since the start of the pandemic [62]. The authors also concluded that different populations responded differently to the psychological stress related to the pandemic [62]. Despite an increased risk for severe COVID-19 outcomes in the elderly, the older age groups in our sample reported better mental HRQOL than younger people. This might be related to increased resilience at older age [46, 63]. COVID-19 was more prevalent in the Italian and French speaking part of Switzerland during the time of our study [64]. Persons from these regions reported lower mental HRQOL before [46] and during the pandemic.

Changed daily routines and the massive cut on social life might have contributed to lower mental HRQOL. Increased parental duties with suspended childcare and home schooling might have further impaired mental HRQOL. We found lower mental HRQOL in persons living alone and persons living with parents and/or children in the same household, but not in participants with partner and children in the same household. Previous studies from the US, Australia and Italy found also a relationship between more childcare and lower mental health or more psychological distress [37, 65, 66]. A systematic review found that parents experienced high stress, anxiety, and financial burden during pandemics [67]. Mental HRQOL was lower in individuals who felt socially isolated and in those who had no one to ask for support. Loneliness was a risk factor for decreased mental well-being and life satisfaction before and during the pandemic [68‐70], and decreased social interactions during the pandemic were associated with reduced quality of life and increased depression [71]. We found that individuals who have already had COVID-19 had a lower mental HRQOL, possibly because some of them had persistent symptoms. Similarly, in US patients, the burden of symptoms persistent for at least six months after mild COVID-19 was associated with low mental HRQOL and psychological distress [72].

Low health literacy was a risk factor for both, low physical and low mental HRQOL during the pandemic in Switzerland. This was similar in a large systematic review and meta-analysis in populations with chronic diseases [73]. A study among the Japanese general population found that individuals with higher health literacy before the pandemic reported a smaller decline in physical and mental HRQOL during the pandemic [38]. Health literate individuals have better capacities to access, understand and interpret health information, and to use this knowledge to make decisions for prevention and actions in health issues. This ability may help them to better cope with a major health crisis, such as the COVID-19 pandemic [74].

Our study has the limitation of using a convenience sample which overrepresents women and well-educated participants and preventing us from being able to calculate a response rate. This is due to biases arising from our recruitment strategy [75], but alternative recruitment designs were not attainable to us. Swiss legislation did not permit to re-contact participants from the SGP sample and it was not possible to get another representative sample from SFSO. We have adjusted for age, sex, and education in all our regression analyses to account for differences in these variables between the CoWELL and the SGP sample. Yet, conclusions largely apply to well-educated women and might not be similar for the Swiss general population. Our study has the strengths of being able to compare HRQOL from before to during the pandemic, to include a large number of participants, and to use a wide range of traditional socio-demographic, socio-economic, and COVID-19-related covariables. This allowed us, with good statistical power, to disentangle the pandemic-specific impact on HRQOL. The study started two months after introducing preventive measures in Switzerland, which allowed to measure direct pandemic effects on HRQOL, when people had not yet fully adapted to pandemic routines. We assessed HRQOL with the SF-36, a widely used psychometrically valid instrument [44], and used recent SF-36 normative data from Switzerland, which ensured a recent and appropriate comparison sample for HRQOL in Switzerland.