A number of studies have documented relationship between various individual outcomes and birth order. This study sought to investigate the relationship between adolescents health behavior, stress and birth order.

The data used in this study were obtained middle and high school students who replied to the 10th Korea Youth Risk Behavior Web-based Survey (KYRBWS) administered in 2014. We investigated the associations between health behavior, stress and birth order using multivariable logistic regression analysis controlling with age, height, weight, father’s education, mother’s education, economic status, academic status, sleep duration, sitting time, self-perceived health status, self-perceived happiness, depression mood, suicide idea, suicide plan, suicide attempt, drinking experience, smoking experience.

The distribution of first-born was 45.5% and later-born was 54.5%. In multivariable logistic regression the later-born replied higher portion of vigorous physical activity 3 days per week and strength exercise 5 days per week. And later-born replied lower economic status, lower academic performance and higher prevalence of drinking experience, smoking experience. Later-born they had more stress than first-born, but after adjusted for variable factors in multivariable logistic regression, birth order had no relationship with stress significantly.

This study offers data for the development of intervention programs to adolescent related to birth order, and further study is necessary in order to clarify adolescent’s relationship between birth order and stress and individual outcomes.