Diagnosing disparities

• The eGFR (estimated glomerular filtration rates) calculations stand as one of the most prominent in measuring kidney function and systemic maladies. [1]

• However, based on studies conducted in the past three years, this investigation type has proven inaccurate and biased in the face of comparisons between Black and White patients.

• Current eGFR calculations use a person’s age, sex, and serum creatinine levels. Serum creatinine is a waste product from metabolism in the muscles, which is filtered by the kidneys. These variables have now been noted to be biased in nature and unreliable as a form of investigation. [2]

• African Americans have been found to contain higher levels of serum creatinine regardless of kidney function, thus distorting the eGFR calculations to present with a lower level of kidney function than what is accurate.

• Following this, an article by Inserro, A, presented the idea that using race as a determinant of risk and kidney function was harmful as it already embedded biases within the medical investigation without conducting clinical tests

• This meant that physicians were assigning the label of higher kidney function to Black patients, resulting in assumed treatment pathways alongside reduced severe care scenarios being enacted when needed and inaccurate pharmacological interventions being prescribed. Thus widening the discrepancy in the standard of care and medical management between Black and White patients. [3]

[1] https://www.nih.gov/news-events/news-releases/nih-supported-study-suggests-alternative-race-based-kidney-function-calculations

[2] https://doi.org/10.1056/nejme2114918

[3] https://www.ajmc.com/view/flawed-racial-assumptions-in-egfr-have-care-implications

• Many studies have found that, on average, Black individuals have lower lung volumes than white people. Therefore, race-based lung function equations used to convert lung volumes into age, sex and height adjusted measurements assume that lower lung volumes are expected, and hence “normal,” in Black people.

• However, the knowledge that the prevalence and incidence of respiratory illnesses is greater in Black patients than their White counterparts prompts the need for a readjustment of the appropriateness and accuracy of race-specific prediction equations.

• The consequences of inaccurate and underrepresentation in lung function calculations can be severe, with a White patient potentially receiving treatment than a Black patient who is otherwise identical in disease progression.

• This may also impact who is placed on the lung transplantation list and at what point, as these tests underestimate the potential disease progression of Black patients due to the re-assumption that their lung function is ‘normally’ low.

• Therefore, the need to address the limitations and preconceptions placed on ‘race-based’ function tests must be acknowledged and actioned upon. This is vital in order to approach every patient fairly and with an equal level of competence. [1]

[1] https://www.statnews.com/2020/09/15/lung-function-algorithms-health-disparities-black-people/#:~:text=Race%2Dbased%20lung%20function%20algorithms,normal%2C%E2%80%9D%20in%20Black%20people

• Pulse oximetry is a simple yet essential medical investigation used by practitioners around the globe. It consists of clipping a small device, called a pulse oximeter, to a patient’s fingertip; measuring the oxygen saturation of the patient’s blood through the use of wavelengths to detect the amount of oxygen binding to red blood cells [1].

• While this quick and simple examination has proven invaluable in determining oxygen levels, however it is less accurate than arterial blood gas tests.

• In a study carried out by Valbuena, V et al, it was found that the difference in accuracy between ABG and pulse oximetry meant that severely oxygen-starved (hypoxic- SaO2>88%) patients had been missed in pulse oximetry but shown in ABG readings.

• This phenomenon seems to occur more prominently in Black patients compared to their White counterparts. This would increase the likelihood of mortality and increase the chances of end-organ failure in patients with severe hypoxia

• Therefore, the racial bias seen in the reduced accuracy of the oximeter paired with the disparity in measurements between ABG and pulse oximetry has led to a lesser level of accurate and effective treatment for Black patients in acute settings compared to White patients. [2]

• Looking into a more recent case, Sudat, S et al, conducted a study during one of the peaks of the COVID-19 epidemic (July 2020- Feb 2021). This would focus on the systematic overestimation of blood oxygenation in NHB (non-Hispanic Black patients- one of the two categories measured in this study).

• Meaning, this 1% overestimation of blood oxygen would reduce the rate of admission, pharmacological treatment and oxygen therapy for COVID-19 patients from NHB backgrounds. Thus exacerbating the racial disparities further in medical investigations and its impact on the outcome of treatment for specific racial groups. [3]

[1] https://www.ncbi.nlm.nih.gov/books/NBK470348/

[2] https://doi.org/10.1136/bmj-2021-069775

[3] https://doi.org/10.1093/aje/kwac164

• Temperature readings help guide and inform the diagnosis and course of treatment. They are an essential component of the initial A-E assessment and they provide a baseline idea of what interventions, treatment and escalation is needed. By detecting fevers, medical professionals can gain an understanding of underlying infections or early symptomatic conditions experienced by the patient; thus determining detection timing and treatment quality.

• One study conducted by Emory University in Atlanta, and the University of Hawaii, in Honolulu recorded individually registered oral and forehead temperature readings within an hour of each other on the first day of hospital entry of over 4000 patients. When comparing the temperatures, the researchers found that the forehead readings were lower than the oral temperature readings in Black patients.

• In white individuals, 10.8% had a fever, as indicated by the forehead thermometer, which was similar to the 10.2% rate of the oral thermometer. However, for Black people, there were considerable differences between the two methods. The forehead thermometer detected fever in 10.1% of the Black participants, but this number jumped to 13.2% with the oral thermometer.

• These findings are significant, as temperature detection and recording is a vital component of medical progression and therefore, the treatment given to the patient.

• If Black patients are less likely to have their fever detected by forehead thermometers, they may be more likely to be under-treated or misdiagnosed. This could lead to delayed treatment and poorer health outcomes [1]

[1] https://healthnews.com/family-health/health-screening/study-forehead-thermometers-may-be-less-accurate-on-black-people/#:~:text=of%20skin%20color.-,Racial%20biases%20in%20medical%20equipment,less%20accurate%20in%20Black%20patients

• The use of BMI has been proven to be an outdated index which hasn’t translated effectively beyond the original demographic used to define Body Mass Index.

• The measurement was coined by Belgian statistician Adolphe Quetelet's, who in the 1830s recorded various men's heights and weights at different ages.

• From this study, he used the results to define the ‘average’ man and equated body mass index to the division of an individual's weight in kilograms by their height in metres squared. If you were above a certain BMI score, you were labelled ‘obese’ or ‘at a higher health risk’.

• This form of categorisation of the body has been found to undermine differences in individual factors that impact the body such as lifestyle, ethnicity and muscle mass. Thus reducing its effectiveness and accuracy as a quantifiable measure of obesity and labelling the index archaic in contemporary medical practice.

• It is vital that medicine moves away from the Euro-centric standards placed upon many clinical tests/ investigations.

• This is because those who do not belong to that group fail to receive an accurate and representative model of obesity measurement; potentially harming their idea of obesity, as well as their relationship with health.

• Thankfully, measures like Bioimpedence use a body fat range which is transferable and adjustable to any patient, regardless of age, sex, race or lifestyle. [1]

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2930234/