[Co-occurrence of internalizing and externalizing problems and associations with related factors among preschool...

Objective: To explore the co-occurring characteristics and associations with the related factors of internalizing and externalizing problems among preschool children aged 3-6 years in Yan'an. Methods: A cross-sectional survey was conducted from February 28^th to March 5^th, 2025, in 189 public kindergartens across 13 districts (counties) in Yan'an, Shaanxi Province. A total of 28 000 questionnaires were distributed. The survey collected information including children's age, sex, parental demographic characteristics, family economic status, and lifestyle factors. Children's behavioral problems were assessed using the parent-reported strengths and difficulties questionnaire (SDQ). Grouped by sex. Based on the presence of internalizing and externalizing problems, participants were classified into 3 groups: no problems group, internalizing-only or externalizing-only problems group, co-occurring internalizing and externalizing problems group. Pearson's chi-square test was used for groups comparisons. Multinomial Logistic regression models analysis was conducted. Results: A total of 16 159 valid questionnaires were included, comprising 8 301 boys and 7 858 girls, with the age of (4.8±0.9) years. Among them, 5 289 children (32.73%) had behavioral problems, including 3 598 (22.27%) with the single problem and 1 691 (10.47%) with co-occurring problems. Using the no-problem group as the reference category, after false discovery rate (FDR) correction, maternal age >40 years (OR=0.69, 95%CI 0.53-0.91, q=0.044), maternal education at the senior high school (college) level (OR=0.74, 95%CI 0.64-0.85, q<0.001) or bachelor's degree or above (OR=0.67, 95%CI 0.54-0.82, q=0.002), annual household income of ≥100 000 to <200 000 RMB (OR=0.66, 95%CI 0.55-0.78, q<0.001), and outdoor activity time ≥3 h per day (OR=0.76, 95%CI 0.68-0.84, q<0.001) were all negatively associated with co-occurring problems. Paternal unemployment was positively associated with co-occurring problems (OR=1.73, 95%CI 1.30-2.31, q=0.002). Maternal education at the senior high school (college) level (OR=0.87, 95%CI 0.78-0.96, q=0.046) and outdoor activity time ≥3 h per day (OR=0.88, 95%CI 0.81-0.95, q=0.006) were both negatively associated with the single problem, whereas screen exposure >1 h per day was positively associated with the single problem (OR=1.40, 95%CI 1.26-1.56, q<0.001). Conclusions: Co-occurring internalizing and externalizing problems are common among preschool children in Yan'an. Maternal age, maternal education level, paternal employment status, household income, and children's lifestyle factors are associated with co-occurring problems.