School entry health examinations by school nurses for early detection of psychiatric disorders: a prospective cohort study.

Abstract

Background: Mental disorders are a major contributor to the burden of disease in children and adolescents, with peak age of onset in mid-adolescence. In Denmark, almost all children participate in a school health nurse examination at school start. This study aimed to investigate whether the school health nurse examination of children's well-being, developmental and relational risk indicators at age 5-7 years can predict incident psychiatric illness before age 16 years.

Methods: This prospective population-based cohort study followed 26,053 children from the school health nurse examination at age 5-7 years to age 16 years. School health nurses recorded systematic data on six risk indicators. Data on incident psychiatric illness in the observation period were obtained from national health registers.

Results: The incidence of any psychiatric illness was 11.3%: any behavioral or emotional disorder 7.2%, and any neurodevelopmental disorder 7.1%. All risk indicators were associated with increased risk of any incident psychiatric illness during follow-up [odds ratios 1.36 (1.19-1.55) to 2.23 (2.03-2.45)]. The risk increased with the number of risk indicators: odds ratio 1.94 (1.77-2.12) for at least one, 2.44 (2.17-2.74) for at least two, and 3.20 (2.67-3.83) for at least three risk indicators. Similar patterns were seen for the diagnostic subgroups, with the highest risk among children with at least three risk indicators [odds ratio 2.41 (1.93-3.01) for any behavioral or emotional disorder and 3.81 (3.12-4.44) for any neurodevelopmental disorder]. The predictive validity of all risk indicators showed low sensitivity (< 26%) and positive predictive value (≤ 20%), but high specificity (> 86%) and negative predictive value (> 89%). Diagnostic subgroups showed comparable sensitivity and specificity with lower positive predictive values and higher negative predictive values.

Conclusions: Child well-being, developmental, and relational risk indicators from the school health nurse examination at age 5-7 years were associated with an increased risk of incident psychiatric illness. While predictive validity is limited, these risk indicators may help school health nurses identify children at increased risk, supporting structured and measurement-based attention and guidance to families.