Changes in social behavioral developmental risks in preschool children after the first COVID-19 wave: a prospective longitudinal cohort study.

The impact of the COVID-19 pandemic on social-emotional developmental risks (SE-DR) of preschool children is largely unknown. Therefore, the aim of this prospective longitudinal dynamic cohort study was to assess changes in preschoolers' SE-DR from before the pandemic to after the first COVID-19 wave. SE-DR were assessed annually with the instrument "Dortmund Developmental Screening for Preschools" (DESK). Longitudinal DESK data from 3- to 4-year-old children who participated both in survey wave (SW) three (DESK-SW3, 2019) and SW four (DESK-SW4, 2020) from August 1 to November 30 were used, respectively. Additionally, data from previous pre-pandemic SW were analyzed to contextualize the observed changes (SW1: 2017; SW2: 2018). A total of N = 786 children were included in the analysis. In the pre-pandemic DESK-SW3, the proportion of children with SE-DR was 18.2%, whereas in DESK-SW4 after the first COVID-19 wave, the proportion decreased to 12.4% (p = 0.001). Thus, the prevalence rate ratio (PRR) was 0.68. Compared to data from previous SW (SW1-SW2: PRR = 0.88; SW2-SW3: PRR = 0.82), this result represents a notable improvement. However, only short-term effects were described, and the study region had one of the highest preschool return rates in Germany. Further studies are needed to examine long-term effects of the pandemic on preschoolers' SE-DR.

Cohort Profile: evaluation of the targeted individual promotion in german preschools using the revised Dortmund Developmental Screening for Preschools DESK 3-6 R (project "GIF MV").

This dynamic cohort was established to evaluate the targeted individual promotion of children affected by developmental risks as part of the German federal state law for child day-care and preschools in Mecklenburg-Western Pomerania. The project has been conducted in preschools in regions with a low socio-economic profile since 2011. Since 2017, the revision of the standardized Dortmund Developmental Screening for Preschools (DESK 3-6 R) has been applied. Developmental risks of 3 to 6-year-old children in the domains of motor, linguistic, cognitive and social competencies are monitored. The cohort is followed up annually. In 2020, n = 7,678 children from n = 152 preschools participated. At the baseline (2017), n = 8,439 children participated. Due to the defined age range of this screening, 3,000 to 4,000 5-6-year-old children leave the cohort annually. Simultaneously, an approximately equal number of 3-year-old children enters the cohort per survey wave. N = 702 children participated in all 4 survey waves. On the basis of DESK 3-6 R scores available from survey waves 2017 to 2019 it is possible to compute expected values for the survey wave 2020 and to compare those with the measured values to evaluate the effects of the COVID-19 pandemic (i.e. parental home care due to restrictions related to COVID-19).