Older Age, Poor Immune Response Are Risk Factors for ARDS, Death in COVID-19

Older age and low immune response are major risk factors for acute respiratory distress syndrome (ARDS) and death associated with coronavirus disease 2019 (COVID-19), according to study results published in JAMA Internal Medicine.

Fever, myalgia, and dry cough are the most common symptoms in patients presenting with COVID-19; however, risk factors for COVID-19 have not been well established given existing studies are based on relatively small sample sizes. The objective of this study was to describe the clinical characteristics, risk factors, and outcomes in patients with COVID-19 who developed ARDS or died from the disease.

In this retrospective cohort study, researchers evaluated epidemiological, demographic, clinical, laboratory, management, treatment, and outcome data on 201 patients diagnosed with COVID-19. Patients were aged 21 to 83 years, were admitted to Jinyintan Hospital in Wuhan, China, between December 25, 2019, and January 26, 2020, and were followed through February 13, 2020. Primary outcomes were the development of ARDS and death.

Results revealed that of the 201 patients included in the study, 84 (41.8%) developed ARDS, and of those 84 patients, 44 died. At the time of illness onset, the most commonly self-reported symptoms were fever (93.5%), cough (81.1%), productive cough (41.3%), dyspnea (39.8%), and myalgia (32.3%). A total of 66 patients (32.8%) had comorbidities including hypertension (19.4%), diabetes (10.9%), cardiovascular disease (4.0%), liver disease (3.5%), nervous system disease (3.5%), chronic lung disease (2.5%), chronic kidney disease (1.0%), endocrine system diseases not including diabetes (1.0%), and tumors (0.5%).

Compared with patients without ARDS, patients with ARDS were older (difference, 12.0 years; 95% CI, 8.0-16.0 years; P <.001) and had a higher proportion of comorbidities, including hypertension (difference, 13.7%; 95% CI, 1.3%-26.1%; P  =.02) and diabetes (difference, 13.9%; 95% CI, 3.6%-24.2%; P =.002). Additionally, more patients with ARDS presented with initial symptoms of dyspnea (difference, 33.9%; 95% CI, 19.7%-48.1%; P <.001) and had higher temperature prior to admission (difference, 0.30°C; 95% CI, 0.00-0.50°C; P =.004) compared with those without ARDS.

Risk factors significantly associated with the development of ARDS included age o≥65 years, fever of ≥39°C, comorbidities, neutrophilia, lymphocytopenia, elevated end-organ related indices, elevated inflammation-related indices, and elevated coagulation function-related indicators.

In patients with ARDS, those who died were older (difference, 18.0 years; 95% CI, 13.0-23.0 years; P <.001), had a lower proportion of high fever (difference, -31.8%; 95% CI, -56.5% to -7.1%; P =.007), had a higher proportion of hypertension (difference, 18.9%; 95% CI, -2.0% to 39.7%; P =.05), and were less likely to be treated with antiviral therapy (difference, -40.7%; 95% CI, -58.5% to -22.9%; P <.001) than those with ARDS who survived. Treatment with methylprednisolone was shown to reduce the risk of death in patients with ARDS (hazard ratio, 0.38; 95% CI, 0.20-0.72; P =.003).

Limitations to this study included limited medical resources, limited sample size, a single-center design, and possible selection bias when identifying factors influencing clinical outcomes.

The study researchers concluded that poor immune response and older age were associated with a greater risk of ARDS and death in COVID-19. Additionally, fever was associated with better outcomes, and methylprednisolone may be a beneficial treatment for patients with ARDS. Further study is required to determine the most effective treatments for COVID-19.

Reference

Wu C, Chen X, Cai Y, et al. Risk factors associated with acute respiratory distress syndrome and death in patients with coronavirus disease 2019 pneumonia in Wuhan, China [published online March 13, 2020]. JAMA Intern Med. doi:10.1001/jamainternmed.2020.0994