Importance: Childhood exposure to mild traumatic brain injury (mTBI) is common. Individuals with a childhood history of mTBI experience more frequent criminal justice involvement in mid to late adolescence and adulthood. No study had been conducted to examine whether the link is causal or spurious.
Objective: To determine whether mTBI in childhood causes criminal justice involvement in mid to late adolescence.
Design, setting, and participants: This cohort study used population-based data for all children born between 1995 and 2000 in Denmark, with data linked to emergency department (ED) visits and hospitalizations before age 10 years and all criminal charges and convictions from ages 15 to 20 years. The exposure group contained all individuals diagnosed with mTBI before age 10 years without other intracranial or extracranial injuries; the comparison group was individuals not diagnosed with mTBI or intracranial or extracranial injuries. Sibling and twin fixed-effects models were used to evaluate the association after controlling for family-level confounding. Data were analyzed from May 2021 to July 2024.
Exposures: Mild TBI before age 10 years without other intracranial or extracranial injuries before or at the time of diagnosis.
Main outcomes and measures: Associations between mTBI before age 10 years and criminal charges and convictions from ages 15 to 20 for the entire study population and separately by sex at birth, controlling for additional covariates.
Results: The final analytic sample consisted of 343 027 individuals, 13 514 in the exposure group and 329 513 in the comparison group. Of the total sample, 166 455 (49%) were female and 176 572 were male (51%). A total of 326 191 participants (95%) had at least 1 parent with Danish citizenship, and 79 386 mothers (23%) held a college degree. There was a positive association between mTBI and criminal charges (odds ratio [OR], 1.26; 95% CI, 1.19-1.34) and convictions (OR, 1.24; 95% CI, 1.16-1.33). When controlling for family-level confounding, the associations became statistically insignificant and, in most models, greatly reduced. Results were robust across multiple model specifications.
Conclusions and relevance: This study found that although mTBI in childhood was predictive of adolescent criminal justice involvement, there was no evidence that mTBI caused criminal charges or convictions.
Importance: The prevalence estimates of physical activity, sedentary behavior, and sleep (collectively known as movement behaviors) in 3- and 4-year-old children worldwide remains uncertain.
Objective: To report the proportion of 3- and 4-year-old children who met the World Health Organization guidelines for physical activity, sedentary behavior, and sleep across 33 countries.
Design, setting, and participants: Pooled analysis of data from 14 cross-sectional studies (July 2008 to September 2022) identified through systematic reviews and personal networks. Thirty-three countries of varying income levels across 6 geographical regions. Each study site needed to have at least 40 children aged 3.0 to 4.9 years with valid accelerometry and parent-/caregiver-reported screen time and sleep duration data. Data were analyzed from October 2022 to February 2023.
Exposures: Time spent in physical activity was assessed by reanalyzing accelerometry data using a harmonized data-processing protocol. Screen time and sleep duration were proxy reported by parents or caregivers.
Main outcomes and measures: The proportion of children who met the World Health Organization guidelines for physical activity (≥180 min/d of total physical activity and ≥60 min/d of moderate- to vigorous-intensity physical activity), screen time (≤1 h/d), and sleep duration (10-13 h/d) was estimated across countries and by World Bank income group and geographical region using meta-analysis.
Results: Of the 7017 children (mean [SD] age, 4.1 [0.5] years; 3585 [51.1%] boys and 3432 [48.9%] girls) in this pooled analysis, 14.3% (95% CI, 9.7-20.7) met the overall guidelines for physical activity, screen time, and sleep duration. There was no clear pattern according to income group: the proportion meeting the guidelines was 16.6% (95% CI, 10.4-25.3) in low- and lower-middle-income countries, 11.9% (95% CI, 5.9-22.5) in upper-middle-income countries, and 14.4% (95% CI, 9.6-21.1) in high-income countries. The region with the highest proportion meeting the guidelines was Africa (23.9%; 95% CI, 11.6-43.0), while the lowest proportion was in North and South America (7.7%; 95% CI, 3.6-15.8).
Conclusions and relevance: Most 3- and 4-year-old children in this pooled analysis did not meet the current World Health Organization guidelines for physical activity, sedentary behavior, and sleep. Priority must be given to understanding factors that influence these behaviors in this age group and to implementing contextually appropriate programs and policies proven to be effective in promoting healthy levels of movement behaviors.