It is well documented that comorbidities predispose adults to develop serious illness. The question is whether the risk factors are the same for young adults as they are for older adults. Mulaney et al. investigated this and found that the risk factors for critical illness associated with SARS-CoV-2 differ between these two age groups.
The retrospective study by Mulaney et al. Examines more than 6,900 medical records, correlating the effects of age, comorbidities, and symptom severity from SARS-CoV-2 infection.
Participating patients included individuals who were hospitalized after receiving a positive SARS-CoV-2 test from June 31 to November 15, 2021. Patients receiving mechanical ventilation were excluded from this study. The sample ranged from 51 hospitals to 1,081 clinics in five states. The patients were then divided into two subgroups: younger (18 years and <50 years with 1963 patients) and older (50 years old with 4943 patients).
Mulaney et al. hypothesized that these age stratified groups would allow an adequate interpretation of mortality due to SARS-CoV-2, based only on the patient’s medical background. Some of the factors analyzed in this study include patient demographics, medical history, vital signs, and laboratory biomarkers. Given the varying conditions of each patient, they analyzed the group as a whole as well as by age group. This would help circumvent differences in pre-existing chronic diseases, or even vaccination status.
The three main findings are: 1) risk models are effective in analyzing clinical data, 2) vital signs and laboratory test results at the time of admission are more important in predicting severe COVID-19 symptoms than presence of comorbidities, 3) age stratified models show that symptom severity among young adults Older people with COVID-19 are different.
Statistical analysis revealed new information about how variables that correlate with severe infection or even death due to SARS-CoV-2 differ between younger and older age groups. For example, Mulaney et al. It found that younger patients with concomitant heart disease and a higher BMI are more likely to suffer severe symptoms than older patients. Conversely, older patients with dementia or vasopressors are more likely to have severe symptoms of SARS-CoV-2 than younger patients (Table 1).
From the analysis, Mulaney et al. Note that BMI is a greater predictor of the severity of SARS-Cov-2 for young adults. No significant association is shown among the older population. Mulaney et al. note that future investigations may include stratified BMI models to determine the risk of being underweight or overweight in young adults.
They also found that many comorbidities such as elevated AST that lead to liver damage, elevated creatinine that impair kidney function, lower calcium levels, increased age, and higher BMI put younger populations at greater risk for severe Covid-19 symptoms. Finally, for young and elderly patients, screening of vital signs and laboratory testing for predictions is more effective most of the time, rather than relying on comorbidities and patient demographics.
This study highlights the need for early risk stratification in patients with SARS-CoV-2 to determine the level of care a patient is likely to require. Mulaney et al use readily available data such as demographics, vital signs, laboratory tests, and medical history to predict SARS-CoV-2 virus severity in a patient. As a result, the age stratified modeling approach provides us with a more comprehensive understanding of patients’ risk factors and how this needs to translate into healthcare decisions that are made.