The relationship between childhood asthma and socioeconomic status: a Korean nationwide population-based study

PURPOSE: This study aimed to investigate associations of socioeconomic status (SES) with asthma exacerbation and asthma-related hospital utilization factors among children with asthma in the Republic of Korea. METHODS: This study retrospectively analyzed population-level data from the Korean National Health Insurance Service, collected from 2013 through 2019. SES was classified into five categories according to the national health insurance premiums quantiles (0 [lowest] to 4 [highest]). The hazard ratios (HRs) for asthma exacerbation, emergency department (ED) visits, hospital admission, and intensive care unit (ICU) admission were analyzed with respect to SES. RESULTS: Among the five SES groups, SES group 0 (medical aid), had the highest tallies and proportions of children who experienced asthma exacerbations (n = 1,682, 4.8%), ED visits (n = 932, 2.6%), hospital admission (n = 2,734, 7.7%) and ICU admission (n = 14, 0.04%). Compared with SES group 4, SES group 0 had adjusted HRs of 3.73 (p = 0.0113) and 1.04 (p < 0.0001) for ventilator support/tracheal intubation and administration of systemic corticosteroids, respectively. Relative to group 4, the adjusted HRs for ED visits, hospital admission, and ICU admission in group 0 were 1.88 (p < 0.0001), 2.20 (p < 0.0001), and 7.12 (p < 0.0001), respectively. In the survival analysis, group 0 had a significantly higher risk of ED presentation, hospital admission, and ICU admission than the other groups (log-rank p < 0.001). CONCLUSION: Compared with children of higher SES, those in the lowest SES group had increased risk of asthma exacerbation, hospital admission, and receiving treatment for severe asthma symptoms.