US study assesses COVID-19 complications, says patients at 27.6% risk of pneumonia

Since the beginning of the COVID-19 pandemic, scientists and healthcare experts from around the world have observed a number of complications that the SARS-CoV-2 virus can lead to. The COVID-19 infection is primarily a respiratory infection and studies that highlight the devastating damage severe COVID-19 can do to the lungs were some of the first to emerge. One study even pointed out that high-oxygen flow from ventilators to critically-ill COVID-19 patients can severely damage the lungs and cause abscesses and pneumonia.Another study in the American Journal of Emergency Medicine in July 2020 pointed out that not only does the COVID-19 infection have the potential to cause systemic inflammation and multiorgan dysfunction but it can also affect the cardiovascular system and cause complications like myocardial injury, myocarditis, acute myocardial infarction, heart failure, arrhythmias and venous thromboembolic events. Neurological injuries and brain damage with short- and long-term consequences have also been indicated by some research. Studies show that children, who usually do not get severe COVID-19, are also suffering from multisystem inflammatory syndrome (MIS) and Kawasaki disease.Assessing complications of COVID-19While quite a few studies highlight the major complications associated with COVID-19 disease, most of them have involved small subject groups. This, while proving that certain complications can arise during and after COVID-19 disease, does not provide enough data to establish a cause-and-effect link with COVID-19. What’s more, these studies do not provide risk estimates associated with COVID-19, which could be of great help to healthcare professionals in different care settings across the world.A new study published in the Canadian Medical Association Journal (CMAJ) not only hopes to overcome these shortcomings but also assess the actual risks of a full range of COVID-19 complications to aid in determining the prognosis, guide treatment and care protocols and help the patients understand the scope of the disease better. To do this, the researchers behind this large study collected data from the United States’ medical claims database. They compared the frequency of complications before and after the onset of the COVID-19 pandemic based on the International Classification of Diseases, 10th Revision (ICD-10).The actual risks of COVID-19 complicationsThe researchers included 70,288 patients with a diagnosis of COVID-19 between 1 March and 30 April 2020 and computed the risk estimates and odds ratios (OR) of COVID-19 complications using ICD-10 diagnosis codes. In epidemiological and related studies, OR represents the measure of association between exposure to a pathogen and the odds of contracting the disease. If the calculated OR is equal to 1, then the odds of getting the disease are not affected by the exposure measure. If the OR is more than 1, then the odds of contracting the disease is higher and OR less than 1 means lower odds of contracting a disease.In this study, the median age of the patients was 65 years and 55.8 percent of them were female. More than 50 percent of the patients had to be hospitalised and approximately 5 percent of them had to be admitted to the intensive care unit (ICU). The researchers found that among this huge patient cohort, 69 out of 1,724 diagnosis codes in ICD-10 had a significant association with COVID-19. The following were the complications that showed both a strong association with COVID-19 and a high absolute risk of incidence in most cases:

• Viral pneumonia - OR 177.63, absolute risk 27.6%
• Respiratory failure - OR 11.36, absolute risk 22.6%
• Acute kidney failure - OR 3.50, absolute risk 11.8%
• Sepsis or systemic inflammation - OR 4.23, absolute risk 10.4%

The study also showed that some complications showed a strong association with COVID-19, but had a lower absolute risk of actually occurring:

• Myocarditis - OR 8.17, absolute risk 0.1 percent
• Disseminated intravascular coagulation (clots in small blood vessels) - OR 11.83, absolute risk 0.1%
• Pneumothorax or lung collapse - OR 3.38, absolute risk 0.4 percent

The researchers surmised that though the odds ratio of blood clots was high, the very low absolute risk estimate indicates that COVID-19 may not lead to a higher risk of strokes. The study concluded that understanding the risks of these complications linked to COVID-19 can help healthcare professionals across the world provide better care, design better treatment protocols and counsel their patients better.For more information, read our article on Complications of severe COVID-19 infection. Health articles in Firstpost are written by myUpchar.com, India’s first and biggest resource for verified medical information. At myUpchar, researchers and journalists work with doctors to bring you information on all things health.