gms | German Medical Science

Background: Self-rated health (SRH) is an important measure to assess general population health and often used to monitor health trends over time. It somewhat came as a surprise when analyses of survey data found improvements in SRH of the general population during the first wave of the COVID-19 pandemic in Germany in 2020. As an explanation, scholars referred to the lockdown situation which had slowed down working life and had changed leisure activity patterns for many. Literature also suggested that the reference circumstances under which the personal health was commonly evaluated had changed due the impression of the emerging pandemic. Besides these substantial explanations, survey methodological issues had to be considered since the lockdown (contact restrictions) had an impact on data collection routines and sampling probabilities of particular groups. We explore these substantial changes and investigate methodological issues of SRH in the first wave of the COVID-19-pandemic by analysing the following questions: How did mean self-rated health change with the onset of the pandemic? What was the size of the effect? Did changes in interviewer mode play a major role?

Methods: Data from the telephone survey German Health Update (GEDA 2019/2020-EHIS) covering time spans from 02/2020 to 06/2020 and 04/2019 to 06/2019 as well as data from two waves of the German Socio-Economic Panel study (SOEP) collected from 02/2020 to 06/2020 and 02/2019 to 06/2019 were used. In both surveys, SRH was measured on a 5-point-scale from 1 (very bad) to 5 (very good). 16 March 2020 was used to define the pre-pandemic phase (before 16 March 2020) and the pandemic phase (from 16 March 2020). Around that date, Germany’s (then) chancellor Angela Merkel announced school closures and comprehensive restrictions of social contacts. The meaningfulness of the date was confirmed by joinpoint regression with a jump model based on weekly GEDA data. To assess the effect of the pandemic mean differences in the SRH measure between the pre-pandemic and pandemic phase were estimated. For GEDA-data the pandemic phase of 2020 was also compared to the same time span in 2019 to consider seasonal effects. For the SOEP data, differences of the years 2019 and 2020 between the phase before and after 16 March were compared applying a Differences-in-differences (DiD) approach. All estimated differences were adjusted for sociodemographic variables, education, health characteristics and for survey variables in the SOEP data (i.e. subsample membership and survey mode) using linear regression. Probability weights were applied to consider the selection processes for participation and adjust the sample to match official German population distributions.

Results: Results show a significant rise in mean SRH from the pre-pandemic to the pandemic phase in both samples (GEDA: b=0.087, CI95% 0.033-0.140; SOEP: b=0.098, CI95% 0.042-0.155) in 2020. For GEDA the mean difference in SRH for the pandemic phase and the same time span in 2019 was b=0.180 (CI95% 0.143-.216). It was b=0.106 for SOEP (CI95% 0.061-0.153). The DID-approach effect estimated for the SOEP was b=0.137 (CI95% 0.077-0.198).

Conclusion: The results confirm an improvement in mean SRH during the first wave of the COVID-19 pandemic in Germany. Effect sizes were similar in both samples despite changes of the regular interview mode (from CAPI to telephone) for large parts of the SOEP sample, which had been necessary due to the contact restrictions from 16 march on. No mode changes from telephone survey were necessary in GEDA. It is concluded that possible mode effects on SRH were negligible in the SOEP sample. Further research on the volatility of SRH is needed since SRH is relied upon in common composite measures like SF-12 and the minimal health module (MEHM).

The authors declare that they have no competing interests.

The authors declare that an ethics committee vote is not required.