Socioeconomic gradients in parent-reported SDQ scores among children aged 2, 4 and 6 years

Background

Social inequalities in child and adolescent health are well established. In Norway, studies using registry data have shown socioeconomic gradients in diagnosed mental disorders among children and adolescents. Studies using self-reported Strengths and Difficulties Questionnaire (SDQ) data have documented socioeconomic differences among school-aged children. However, registry data may miss early or subclinical difficulties, while self-reported SDQ evidence largely concerns older children. We used parent-reported SDQ data from routine consultations at ages 2, 4 and 6 years to describe early indicators of child mental health difficulties and examine variation by parental income and education.

Methods

Data came from the Starting Right project and collected in 2019-2023. For consenting participants, SDQ data were linked to Statistics Norway registry data on household income and parental education. Income was measured after tax, equivalised using the EU scale and ranked into percentiles. One observation per child was retained, giving a sample of 1,748 children. Analyses included descriptive statistics and regression models of SDQ total difficulties and subscale scores. Models accounted for child age, sex and assessment year. Planned analyses will assess non-linear income gradients.

Results

Preliminary results focused on income and SDQ total difficulties score, showing an income-related gradient in parent-reported difficulties. In adjusted OLS models, each percentile-point increase in household income was associated with a 0.019-point lower SDQ total difficulties score (SE 0.004, p < 0.01). In preliminary linear models, this corresponds to an estimated difference of 1.5 points in SDQ total difficulties between the 10th and 90th income percentiles. The pattern was similar for girls and boys, although girls had lower scores.

Conclusions

Preliminary findings indicate an income-related gradient in parent-reported indicators of early child mental health difficulties.

Key messages

• Parent-reported SDQ data from routine child health consultations can reveal socioeconomic gradients in early child mental health.

• Children from lower-income households showed higher SDQ difficulty scores, highlighting early inequalities that preventive services may help address.