New study published in British Journal of Sports Medicine: Exercise protects against serious COVID-19 outcomes

Authors
Lizelle Steenkamp (Senior Healthcare Statistician at Discovery Health)

• The study, published by the British Journal of Sports Medicine on 10 February 2022, is titled "Small steps, strong shield: Directly-measured, moderate physical activity in 65 361 adults is associated with significant protective effects from severe COVID-19 outcomes"

The health benefits of regular physical activity have been repeatedly and methodically demonstrated.^1-3 Increasingly, and particularly in the context of the COVID-19 pandemic, there is interest in the potential effect of physical activity on the immune system, principally pertaining to shielding against communicable diseases such as COVID-19.^4,5

Discovery Health's analyses draw on 45 million life years of health and wellness data

Discovery Health is South Africa's largest private health insurance administrator, providing comprehensive healthcare insurance to more than 3.7 million people in South Africa. Discovery Health therefore has extensive access to claims and private health system utilisation data and is uniquely positioned to generate at-scale real-world insights into the impact of COVID-19.

• By 9 February 2022: 561,839 confirmed cases of COVID-19 had been recorded among administered medical scheme members, with 75,428 COVID-19 admissions and 15,212 related deaths.

Combined, Discovery Health's data on health and mortality, with Discovery Vitality data on lifestyle and wellness spans a total of 45 million life years. Access to this sizeable pool of information allows clinical research and actuarial teams to perform ongoing advanced disease risk modelling, across various fronts.

Study aims
In this study we set out to investigate whether engagement in the healthy lifestyle behaviours encouraged and rewarded through the Vitality programme - physical activity in particular - reduce one's risk of experiencing severe COVID-19 outcomes (hospitalisation, admission to ICU, ventilation, and death).

Our approach
We grouped directly measured physical activity data - from 65 361 adult patients who were diagnosed with COVID-19 between 19 March 2020 and 30 June 2021 - as follows:

• Low physical activity < 60 minutes/week
• Moderate physical activity (60-149 minutes/week)
• High physical activity >= 150 minutes/week.

The association between physical activity levels and the risk of adverse outcomes was analysed using modified Poisson regression.

We accounted for member demographics and comorbidities, including conditions known to influence COVID-19 outcomes ^6,7, as well as patient complexity as measured by the Johns Hopkins Adjusted Clinical Group (ACG) system. The regression approach was further validated with a Bayesian Network model.

Our findings
In the study population of 65 361 adult patients:

• 11.1% were hospitalised for COVID-19
• 2.4% were admitted to the ICU
• 1.3% were ventilated
• 1.6% died.

We accounted for demographic factors and other risk factors that may explain these findings. Compared to medical scheme members who do the least (Low) physical activity, patients in the High Activity exercise band were found to have a:

1. 34% lower risk of admission
2. 41% lower risk of ICU admission
3. 45% lower risk of requiring ventilation
4. 42% lower risk of death.

However, even moderate physical activity was associated with lower severity of COVID-19 disease. Compared to medical scheme members who do the least (Low) physical activity, patients in the Moderate Activity band have a:

1. 13% lower risk of admission
2. 20% lower risk of ICU admission
3. 27% lower risk of requiring ventilation
4. 21% lower risk of death.

It is clear that high levels of physical activity are extremely beneficial in lowering the risk of serious COVID-19 outcomes, and it is highly encouraging that these protective effects remain even at moderate levels. These effects are apparent even in people who have one or more chronic medical conditions. Please read the study in full, as published in the British Journal of Sports Medicine.

A note of thanks from Lizelle Steenkamp to study co-authors

I would like to thank Professor Jon Patricios (Wits Sport and Health - WiSH - School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand) and his team for their guidance and expertise and for the time spent in shaping the research manuscript appropriately for publication. I'd also like to them Prof Patricios and his team for leading and holding fast the global collaboration that was required to bring this study to fruition. In addition, I would like to thank my co-authors for their invaluable contributions to this research.

They are:

• Robin Terence Saggers
• Rossella Bandini
• Saverio Stranges
• Yun-Hee Choi
• Jane S Thornton
• Simon Hendrie
• Dr Deepak Patel
• Shannon Rabinowitz

Interested in knowing more or reporting on these findings?

Please contact MEDIA_RELATIONS_TEAM@discovery.co.za for updated data and more information on the context of this analysis.

Did you find this post interesting?

You may also be interested in reading a related post about other interesting factors that influences one's risk of serious COVID-19 outcomes. Our analysis shows that well-controlled blood-glucose levels and following a diabetes care programme are linked with a lower risk of serious outcomes.

References

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