Black people, Asians and Hispanics hospitalised with Covid are four times likely to die compared to their Caucasian counterparts, according to a new international study led by University of Cape Town (UCT) cardiologists.
The main predictors of mortality were older age, over 60, male, pre-existing coronary heart disease, diabetes, renal disease, severe Covid infection with higher respiratory rates and requiring ICU admission and oxygen.
Patients from low, lower-middle and upper-middle income countries were at significantly greater risk of mortality than high-income countries.
Professor Karen Sliwa – one of the principal investigators of the study and director of the Cape Heart Institute at UCT’s faculty of health sciences – says the study represents the first comprehensive global data on mortality, cardiovascular outcomes, and cardiovascular risk factors among hospitalised Covid patients recruited from diverse populations.
Researchers found that HIV status was positively associated with 30-day mortality but not in-hospital deaths, suggesting a differential immune response, like lower likelihood of cytokine storm during acute illness but other susceptibilities coupled with health system factors affecting increased 30-day deaths.
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Forty hospitals from 23 countries, including SA, recruited 5 313 Covid patients for the study and the team collected data on demographics and pre-existing conditions at hospital admission, clinical outcomes at hospital discharge (death, major adverse cardiovascular events, renal failure, neurological events, and pulmonary outcomes), 30-day vital status, and rehospitalisation.
This is the first global study to explore the relationship of hospital level resources and country income status with the clinical outcomes, with hospital level resources and facility data gathered from each participating hospital.
Dr Glenda Davison, associate professor and head of the biomedical sciences department at Cape Peninsula University of Technology, said the study, published in the Global Heart Journal, was important as it included patients from hospitals across the world.
Lack of resources
She said the fact that lower income countries have a higher rate of hospitalised death was not too surprising and could be explained by the lack of resources and medical staff in those countries.
Davison said another reason could be the low vaccination rate in many lower-income countries, adding that jabs reduced the severity of Covid, hospitalisation and death, and the unequal distribution would affect this. She said the finding on risk of death among Asians, blacks and Hispanics was important, especially for SA with such a diverse population.
“Pre-existing comorbidities could be an explanation, but in many cases, particularly in Africa, these often go undiagnosed and therefore patients don’t receive appropriate treatment…
“An article published in the South African Medical Journal in 2012… demonstrated that in the mixed ancestry community in Cape Town, there was a 28% incidence of prediabetes and diabetes, which is much higher than in other populations,” Davison said.
She said it was also well know that Africans have a higher incidence of hypertension, many of which go undiagnosed, uncontrolled and untreated.
Davison said the research was very important, not only for how to tackle Covid, but also for how to diagnose and treat underlying comorbidities.
Dr Jo Barnes, Stellenbosch University epidemiologist, said it was good a formal study has confirmed what has been a point of discussion among many healthcare workers looking after hospitalised Covid patients.
She said in interpreting these findings, one should bear in mind that in many countries in the northern hemisphere, where such research is often done, the susceptible groups highlighted in the present study were often first-generation or second-generation immigrants.
Barnes said many observations originated in the US or Europe and a significant proportion of such immigrants were also found at the lower-end of the income spectrum.
“Nutrition, access to healthcare, quality of safe housing, safe neighbourhoods and employment status are all determined by income level and at the same time are factors that influence resistance to infectious disease.”
However, Barnes said – according to general discussion about the links – the association between serious outcomes for Covid and belonging to the groups concerned held true even when low income has been compensated for.
She said the precise genetic basis for such associations are being unravelled, but the links are likely to be complex.
– siphom@citizen.co.za
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