The Role of SES on Health Outcomes
Edited by: Temi Toba-Oluboka
Social economic status also referred to as SES is a term that is generally used to describe an individual's wealth; however, it encompasses many attributes of an individual’s life. Scientists typically have difficulty with defining SES; however, most do use the following definition: “[it] is defined as an individual’s social or economic standing and is a measure of an individual’s or family’s social or economic position or rank in a social group” (Sahni et. al, 2017). It usually includes information on the individual’s income, education, and employment. The concept of SES can be applied to on a national level, where we will hear terms such as low-income, middle-income, and high-income countries, and those who live in low-income have a lower quality of life and high levels of mortality. However, in high-income countries such as the US and Canada there are disparities (I.e., differences) in health outcomes based on one’s SES.
Here at ENAYBLE we want to ensure that everyone, no matter their SES standing has access to the exercise, physical activity, and the education behind their importance. This is because scientists have shown that SES has an inverse relationship with many diseases, such as chronic kidney disease and chronic obstructive pulmonary disease (COPD).
What is an inverse relationship?
This means that as one variable goes up, the other variable goes down. In this scenario, as an individual's SES increases, their risk of developing/the severity of illness decreases. This also means that individuals with lower SES are at a higher risk for certain diseases. You may be wondering, what are the diseases that fall into this category? This post will show some of the research that has been done to show how and potentially why lower SES has this relationship with certain diseases.
Research has shown that pulmonary diseases such as COPD, asthma, cystic fibrosis, pulmonary hypertension and other chronic respiratory conditions are all related to SES (Sahni et. al, 2017). SES has been shown to have a large effect on an individual’s life expectancy and is a risk factor for death. Studies and reviews have also found that there is an increased risk related to cardiovascular disease, access to invasive cardiac procedures, chronic kidney disease, diabetes mellitus and cancer survival.
It can be difficult for researchers to measure SES; they will typically use social and economic conditions that may affect many individuals living in the same place. Therefore, they look at neighbourhood levels, such as ZIP codes, census tracts, census block groups or census blocks and take the mean household income. It would be more accurate to ask each participant in their study questions related to SES; however, they rarely use health records which do not contain that information.
There are many diseases and health outcomes that researchers have explored in relation to SES, to keep this post a bit shorter, I will discuss 4 health outcomes, COPD, asthma, stroke and obesity.
** The following information comes from Sahni et. al, 2011
COPD is a disease that can be reversed/improved and SES can influence one’s access to care. Depending on one’s access to care, their SES may contribute to the reversal or cessation of COPD progression. The disparities in outcomes related to COPD are factors associated with SES such as smoking, occupation, environmental pollution, childhood factors and asthma. Multiple studies have found that COPD has a higher prevalence in lower SES populations, in the form of income for both men and women (Sahni et. al, 2011). One study has found that a higher SES was accompanied by higher rates of smoking cessation (Broms et. al, 2004)). Another study included in the review was conducted in Spain and found that those with lower SES had more impairment due to their COPD (Miravitlles et. al, 2011).
Asthma is a “chronic inflammatory condition of the airways”, studies have shown that having a lower SES is associated with asthma severity and prevalence (Sahni et. al, 2011). A study that used patients from Europe, USA, Australia, New Zealand found that the prevalence and incidence of asthma was higher for those in lower occupational class and education group (Ellison-Loschmann et. al, 2007). Other studies have found that asthma severity is also linked to SES (Sahni et.al, 2011), one of the studies was conducted in Canada and found that there was an increased number of asthma attacks in lower SES families (Ungar et.al, 2016). For this Canadian study they were able to conduct interviews with the families to ask about their SES economic status (Ungar et. al, 2016)
In a review conducted in 2015, the authors listed 20 studies that investigated the relationship between socioeconomic status and stroke incidence (Marshall et. al, 2015). The evidence found in the 20 studies was consistent with a previous review (Cox et. al, 2006) performed by this group. Most of the studies found that the incidence, I.e., the number of new stroke cases decreased with a higher SES. However, it does differ among age, sex and the type of stroke one has, this means that a young person of a lower SES is not automatically going to have a higher risk of a stroke compared to an older individual with a higher SES, because their age plays an important role in its risk (Marshall et. al, 2006).
Furthermore, individuals with a lower SES were associated with a 67% increased risk of stroke. A low SES not only increases a person’s risk of having a stroke but dying after the stroke. There have been large cohort studies that have shown an association between SES and mortality in many countries when patients suffered a stroke (Marshal et. al, 2015).
We will take a closer look at this study done by Jaja et. al which was a multicentre study based in Canada and the US. This study focused on spontaneous subarachnoid haemorrhage (SAH), this type of stroke causes bleeding into the space that surrounds the brain and has a high level of mortality and morbidity.
As stated before, the way that authors will predict an individual's SES is difficult, as researchers generally deal with electronic health records and may not be able to directly ask the participant their income or job. In this study, they used median household income for the residents of the patient’s postal code. They then looked at the income distribution and cut it into 5 groups called quintiles. This study included data from 16,531 Canadians and 31,631 American patients. They found that those in the highest quintile (I.e., highest SES standing) for US patients had a significant decrease in their risk for dying after a SAH. With the Canadian patients, there was a slight decrease as well; however, it was not significant. The reason for this could have been the lower sample size used in the Canadian population, along with the differences between Canadian and American health care systems.
Obesity is another disease with an inverse relationship to SES (Krueger et. al, 2015). Obesity can increase the risk of many other health outcomes such as diabetes, cardiovascular diseases, and some cancers (Apovian, 2016). When it comes to the relationship between Obesity and SES, researchers want to understand how a lower SES can lead to an increased risk of Obesity.
The first mechanism is through diet and physical activity. For children and young adults' studies have found that facility-based sports like swimming and golf and participation in most sports would increase based on the family income, except for basketball.This also plays into the role of accessibility and the cost to play a sport. To play soccer or basketball a family only needs to pay for a ball while other sports like golf require you to pay for the club, equipment, and a coach. Therefore, ENAYBLE Health’s goal, is to provide means and support for those in lower income status to be active. The types of foods that one eats can also differ amongst SES groups, and that can be due to the neighbourhood that one lives in. There will be a post on the topic of food desserts and how the way one eats can be influenced by SES, so make sure to be tuned in for that!
SES is a key determinant of health and unlike physical activity or diet, there is no simple fix to increase one’s SES. It is important to be aware of the health disparities that individual’s face. At ENAYBLE we will continue to host workshops and events to help all Canadians understand the importance of physical activity, so they can improve their health and reduce their risk of disease and morbidity.
SES has an inverse relationship with many different diseases such as cardiovascular disease, obesity and respiratory diseases
Families with lower SES status have an increased number of asthma attacks compared to those of a higher SES status.
Individuals with a lower SES have a 67% higher incidence of stroke and increased severity of stroke
SES can increase the risk of obesity due to access to sports and exercise facilities as well as the neighbourhood that individuals live in through food desserts and food security (more to come on this later!)
Apovian C. M. (2016). Obesity: definition, comorbidities, causes, and burden. The American journal of managed care, 22(7 Suppl), s176–s185.
Broms, U., Silventoinen, K., Lahelma, E., Koskenvuo, M., & Kaprio, J. (2004). Smoking cessation by socioeconomic status and marital status: the contribution of smoking behavior and family background. Nicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco, 6(3), 447–455. https://doi.org/10.1080/14622200410001696637
Cox, A. M., McKevitt, C., Rudd, A. G., & Wolfe, C. D. (2006). Socioeconomic status and stroke. The Lancet Neurology, 5(2), 181-188.
Ellison-Loschmann, L., Sunyer, J., Plana, E., Pearce, N., Zock, J. P., Jarvis, D., Janson, C., Antó, J. M., Kogevinas, M., & European Community Respiratory Health Survey (2007). Socioeconomic status, asthma and chronic bronchitis in a large community-based study. The European respiratory journal, 29(5), 897–905. https://doi.org/10.1183/09031936.00101606
Jaja, B. N., Saposnik, G., Nisenbaum, R., Schweizer, T. A., Reddy, D., Thorpe, K. E., & Macdonald, R. L. (2013). Effect of socioeconomic status on inpatient mortality and use of postacute care after subarachnoid hemorrhage. Stroke, 44(10), 2842–2847. https://doi.org/10.1161/STROKEAHA.113.001368
Krueger, P. M., & Reither, E. N. (2015). Mind the gap: race/ethnic and socioeconomic disparities in obesity. Current diabetes reports, 15(11), 95. https://doi.org/10.1007/s11892-015-0666-6
Marshall, I. J., Wang, Y., Crichton, S., McKevitt, C., Rudd, A. G., & Wolfe, C. D. (2015). The effects of socioeconomic status on stroke risk and outcomes. The Lancet. Neurology, 14(12), 1206–1218. https://doi.org/10.1016/S1474-4422(15)00200-8
Miravitlles, M., Naberan, K., Cantoni, J., & Azpeitia, A. (2011). Socioeconomic status and health-related quality of life of patients with chronic obstructive pulmonary disease. Respiration; international review of thoracic diseases, 82(5), 402–408. https://doi.org/10.1159/000328766
Sahni, S., Talwar, A., Khanijo, S., & Talwar, A. (2017). Socioeconomic status and its relationship to chronic respiratory disease. Advances in respiratory medicine, 85(2), 97–108. https://doi.org/10.5603/ARM.2017.0016
Ungar, W. J., Paterson, J. M., Gomes, T., Bikangaga, P., Gold, M., To, T., & Kozyrskyj, A. L. (2011). Relationship of asthma management, socioeconomic status, and medication insurance characteristics to exacerbation frequency in children with asthma. Annals of allergy, asthma & immunology : official publication of the American College of Allergy, Asthma, & Immunology, 106(1), 17–23. https://doi.org/10.1016/j.anai.2010.10.006