Fig. 1From: Lifestyle changes, mental health, and health-related quality of life in children aged 6–7 years before and during the COVID-19 pandemic in South GermanyStudy sample of first-graders was derived from longitudinal SPATZ cohort (birth cohort recruitment took place from April 2012 to May 2013). Four different groups of first-graders were derived (all observations were independent)Back to article page