Influence of Ethnicity Classification Methods on Physical Activity Outcomes Among Adolescents

Area of Science:

• Adolescent Health
• Sociology
• Public Health

Background:

• Physical activity (PA) is crucial for adolescent well-being.
• Ethnic disparities in PA are documented internationally.
• Ethnicity classification methods can influence the detection and interpretation of these disparities, especially in multiethnic populations.

Purpose of the Study:

• To examine how different ethnicity classification methods affect adolescent physical activity outcomes.
• To investigate the impact of various classification approaches on understanding ethnic disparities in physical activity.

Main Methods:

• Secondary analysis of the 2023 Voice of Rangatahi survey data from Aotearoa New Zealand (n=19,776; ages 12-19).
• Physical activity measured using discrete (0-7 days/week) and binary (>4 vs <=4 days/week) variables.
• Ethnicity classified using four methods: Prioritized, Total Response, Single/Combination (8-group), and Single/Combination (15-group).
• Regression and nonparametric tests were applied.

Main Results:

• Asian adolescents reported the lowest PA outcomes, while multiethnic Pacific Peoples/European reported the highest.
• The Single/Combination 15-group method showed the greatest intergroup differentiation.
• The Total Response method attenuated contrasts between groups.
• The Single/Combination 8-group method exhibited the best model fit.

Conclusions:

• The choice of ethnicity classification method significantly influences observed disparities in adolescent physical activity.
• The Single/Combination 8-group method is recommended for research due to its balance of fit and parsimony.
• The Single/Combination 15-group method is valuable for policy and intervention design, offering finer differentiation.
• Selecting appropriate classification methods is vital for accurate disparity identification and developing equitable, culturally responsive interventions.