[Early childhood intervention and children's health development : Exemplary findings and methodological challenges in the use of the school entry examination].

Background: Early childhood intervention is intended to systematically network and customise support services, particularly for socio-economically disadvantaged families. The programmes are universal or selective, but the evidence on their effectiveness is limited.

Aims: The aims of this study were to exemplary analyse whether participants in early childhood intervention services had better development than non-participants using the school entry examination (SEE) as well as to discuss to what extent the SEE can be used to assess the impact of early childhood intervention services.

Methods: We analysed three typical offers of early childhood intervention services (family education; Zukunft für Kinder (ZfK); Kita-U) in relation to full vaccination coverage and age-appropriate development at U9. Data from 4579 Düsseldorf first graders were included. Propensity score matching was used to calculate percentage differences (average treatment effect on the treated; ATT) in terms of immunisation coverage and development between comparable intervention and control groups.

Results: All programmes are associated with a slightly increased probability of full vaccination protection (ATT 2.1 for family education; 2.5 for ZfK; 5.3 for Kita-U). Family education is also associated with a slightly higher probability of age-appropriate development (ATT 1.6), while the probability of age-appropriate development is lower for participants in ZfK (-10.1) and Kita‑U (-4.5).

Discussion: The evaluation of early childhood intervention, especially selective services, is a methodological challenge due to confounding and suitable comparison groups. However, the SEE could be a framework for impact analyses under specific conditions.