Using Oaxaca Decomposition to Study Socioeconomic Inequity of Physical Activity among Children Aged 10–12 Years: A Study in West of Iran

Abstract

Background: Low physical activity (PA) is increasing public health problem. The present study aimed to determine socioeconomic inequality in PA among children aged 10–12 years old in Kurdistan, west of Iran in 2015.

Methods: The present cross‑sectional study was conducted on 2506 children aged 10–12 in Sanandaj, Iran, in 2015. Data on the children’s level of PA were collected
using the Modifable Activity Questionnaire. The concentration index was used to measure inequality and the Oaxaca decomposition to examine the different determinants of the inequality. The data were analyzed in Stata 13 and SPSS 20.

Results: Of the 2506 participants, 40.90% (38.97–42.82) had insuffcient PA. Girls had a lower level of PA than boys (odds ratio [OR] = 0.34; 95% confdence
intervals [CI]: 0.28–0.41) and it is directly related to maternal education (OR = 1.71; 95% CI: 1.18–2.47), the family’s Socioeconomic status (SES) (OR = 2.18; 95% CI: 1.56–3.05), and the place of residence (OR = 1.68; 95% CI: 1.16–2.44). The concentration index for insuffcient PA was -0.25 (95 CI: -0.30 to -0.21), revealing an insuffcient PA in the group with a low SES. The prevalence of insuffcient PA is 51.38% (95% CI: 48.45–54.31) in poor group and 28.40% (95% CI: 22.80–33.99) in the wealthier group. The Oaxaca decomposition showed maternal education and the place of residence was the most important determinants of inequality.

Conclusions: According to the fndings, most of the children especially in the poor groups didn’t have suffcient PA and socioeconomic factors could have the important role.

Keywords: Children, concentration index, Oaxaca decomposition, physical activity, socioeconomic inequality