Introduction
At the end of 2021, it was estimated that more than 24% of children in Eastern Europe and Asia live in poverty due the effects of the COVID-19 pandemic, climate change, high inflation, the energy crisis and numerous humanitarian crises, and these numbers further increased in 2022 due to the war in Ukraine1,2. Although often overlooked, poverty has a large impact on a child’s (respiratory) health. Living in poverty influences all social determinants of health (SDH), which can be divided into material, psychosocial, behavioral and structural determinants3. Material SDH might be the most visible and may have a direct impact on a child’s health, which was also seen after the recession of 2008-20134. Increased prices of food lead to poorer nutritional status whereas the energy crisis leads to cold houses. Children in cold houses are at increased risk of asthma attacks and respiratory infections. This is not only caused by overcrowded houses when people stay indoors, but also by poor ventilation, formation of mold and growth of house dust mite5. An indirect effect of poverty can be seen in parents who experience financial strain, who are less likely to quit smoking and more likely to relapse6. Furthermore, economic recession and unemployment induces a higher probability for smoking by these parents, leading to increased exposure to possible triggers for children with asthma living under those circumstances7,8. Gaffney et al. found that over the past four decades asthma prevalence increased among children but rose more sharply in children with parents in a lower income group9. Additionally, structural SDH may influence health as well, and is defined as socioeconomic, political, cultural and commercial structures that for instance influence accessibility of resources and services across the population such as pediatric health services, childcare, schools, welfare systems but also food marketing.
The effect of socioeconomic circumstances (SEC) on childhood respiratory diseases are especially clear in the development of persistent asthma. In the UK, disadvantages in early-life are associated with a 70% greater risk of persistent asthma in adolescents, with almost two-thirds of the excess risk being explained by both perinatal and environmental mediators, with home environment being more important than more distal exposures outside the home10. Also, early-life risk factors such as maternal smoking during pregnancy and lower rates of breastfeeding in disadvantaged groups have been shown to be mediators for persistence of wheezing11. Similar findings are reported in Australia and the USA12. In a study done in the USA by Case et al, it was found that disadvantaged children with asthma were more likely to have severe asthma compared to more advantaged children13. In another study examining risk factors for life threatening asthma in the USA in minority inner city children, there was a high rate of previous pediatric intensive care (PICU) admissions and growing up in an extremely poor household even doubled the risk for a PICU admission for severe acute asthma14. Interestingly, in the whole study population, only 27.4% of the children previously admitted to a PICU for asthma had been seen by an asthma specialist14. Another important finding in this study group was that 30.5% of the caregivers had symptoms of depression and 56.4% of the caregivers perceived their child’s asthma as well controlled14. Accessibility to a health care system, part of structural SDH, seems to be even more important for this vulnerable minority group.
Similar to asthma, it may be expected that healthcare inequities (HI) also exist for other respiratory diseases at the PICU. Several studies have shown that children from families with a lower income are not only more likely to be admitted to a PICU but are also more severely ill and more likely to die before discharge15-18. This inequality transcends patient-level, since it has been shown that PICU use and PICU length of stay (LOS) is higher when coming from a neighborhood with higher poverty rates compared to neighborhoods with low poverty rates19. It has been suggested that these higher-poverty neighborhoods have less accessibility to the health care system, poor living conditions and a distressed social environment. Indeed, Brown et al showed that in the USA, the physical distance to a PICU increases with poverty20. Besides the psychological effects on a child and its caregivers after a PICU admission, medical (in the case of uninsured patients) but also non-medical costs (transportation, meals) and the necessity to take leave of absence from their jobs can give a huge strain on already financially distressed families21,22. Both the risk of a post-PICU syndrome as well as the financial effects increase with a longer PICU LOS. To our knowledge, only scarce data are available on effects of socioeconomic, environmental and ethnic factors on PICU outcomes in childhood respiratory diseases. Our hypothesis is that disparities in these factors also negatively influence the outcomes of children’s respiratory diseases treated at the PICU.