P3.023: Parent and Youth Perceptions of Neighborhood Safety and Their Associations with Objectively Measured Physical Activity in Adolescents: Evidence from the ABCD Study

Background: Physical activity is essential for adolescent health, reducing the risk of chronic diseases and promoting long-term mental well-being. Neighborhood safety plays a key role in shaping opportunities for physical activity outside of school, but existing evidence remains limited and mixed. The study aimed to investigate the impact of parent and youth perceived safety on objectively measured physical activity using large-scale data from the Adolescent Brain Cognitive Development (ABCD) Study.

Methods: Data were drawn from the two-year follow-up of ABCD study. Parent- and youth-perceived neighborhood safety (PPNS, YPNS) were assessed using the same item of parent and youth version of Neighborhood Safety Questionnaire modified by PhenX (1 = Strongly Disagree to 5 = Strongly Agree). Physical activity was recorded using Fitbit Charge HR2 devices worn for three consecutive weeks. Key outcomes included average daily sedentary minutes, moderate-to-vigorous intensity physical activity (MVPA) minutes, and total steps. Differences in physical activity across safety levels were calculated with Kruskal-Wallis tests. The effects of PPNS and YPNS on physical activity were examined using General Linear Models (GLMs) with between-subjects effects, controlling for puberty stage, BMI, study site and sociodemographic variables.

Results: Among a sample of 6634 participants (M [age] 12.0±0.7 years, 50.9% boys, 28.6% racial/ethnic minorities), only 17.7% met the recommended physical activity guidelines (MVPA≥60 min/day). Kruskal-Wallis tests demonstrated higher perceived neighborhood safety (PPNS/YPNS) was associated with lower sedentary time and higher total steps. MVPA showed inconsistent trends: highest at the highest parent-perceived safety(PPNS=5) but lowest youth perceived safety(YPNS=1), while lowest at neutral ratings(PPNS/YPNS=3). The GLM analysis revealed that both PPNS and YPNS were significantly associated with sedentary time, MVPA, and total steps (PPNS: P< 0.001,Partial η² =0.004; YPNS: P< 0.001, Partial η² =0.003). Between-subjects effects showed that PPNS was significantly associated with sedentary time and total steps (P < 0.001), but not MVPA, whereas YPNS was significantly associated with all three variables (P < 0.001).

Conclusion: Both PPNS and YPNS were significantly associated with physical activity, though distinct patterns emerged. These findings highlight the importance of considering neighborhood safety in the development of physical activity programs among youth.