From published data, it seems that some clinical characteristics of COVID-19 patients are associated with more severe disease course and reports from China and Italy suggest that risk factors for severe disease include older age and presence of at least one of several underlying health conditions (Guan et al. NEJM Feb 2020, COVID-19 surveillance group, Rome, Italy)
We have selected 7 of latest articles that contain information about clinical characteristics & laboratory findings of hospitalized COVID-19 patients. We have selected & summarized those parameters that seems to be correlated to a more severe disease course.
Can some of these parameters be useful in identifying the patients at higher risk of having a more severe course of COVID-19?
Guan et al. published in February data from 1099 hospitalized patients. Comparing Severe to non-severe patients we see that more severe patients had higher % of hypertension, diabetes, CHD. In laboratory findings, patients with more severe disease seems to have lymphopenia, thrombocytopenia, higher CRP levels and higher levels of D-Dimer.
Zhou et al. described the profile of 191 hospitalized patients, comparing the survivors with non-survivors. Very interesting conclusions could be extracted from this article. As we could see in the table, the selected characteristics were significantly different in survivors vs non-survivors:
Clinical characteristics that are significantly more present in non-survivors: hypertension, diabetes, coronary heart disease
Laboratory findings that were significantly different in non-survivors: lymphopenia, thrombocytopenia, higher troponin, higher D-Dimer, higher ferritin and higher IL-6.
Wu et al. described the profile of 201 hospitalized patients comparing those developing ARDS vs the non-ARDS and among the ARDS patients they made the comparison between those that died vs no-death.
Clinical characteristics that are significantly more present in ARDS patients: hypertension, diabetes
Laboratory findings that were significantly different in ARDS vs no-ARDS patients: higher neutrophils, lymphopenia, higher CRP, higher IL-6, higher ferritin and higher D-Dimer.
When comparing ARDS-died vs no-death they found significantly higher count of neutrophils and higher IL-6 in patients that died.
Chen et al. retrospective data from hospitalized moderate-severe patients showed that group of patients who died presented higher % of hypertension, diabetes and CV disease among others characteristics.
Laboratory variables were also different between groups: lower lymphocytes, higher neutrophils, higher CRP, ferritin and D-Dimer in patients who died.
CDC COVID-19 Response Team in the US published data of 7,162 patients, 1/3 of them had at least one underlying condition (37,6%), Diabetes, chronic lung disease and CV disease where the most frequent among all the patients. These risk factors were highly present in hospitalized patients and even higher in ICU patients.
ICU admission was higher for patients with underlying condition (13.3%-14.5%) vs those without underlying conditions (2,2%-2,4%).
Authors stated that diabetes, hypertension, COPD, coronary artery disease, cerebrovascular disease, chronic renal disease and smoking might be at higher risk for severe disease or death from COVID-19.
Arentz et al. have published recently a small recording of 21 ICU patients. No comparison was made versus non-ICU patients. Either way, this small study in the US seems to be consistent with the association of Diabetes and CV disease to more severe COVID-19 course.
Also, levels of lymphocytes and platelets are consistent with those saw in the Wu and Zhou articles.
Graselli et al. has published data from 1591 patients hospitalized in ICU. No comparison was made vs non-ICU patients and still data about outcomes is incomplete.
Hypertension, Diabetes and CV disease seems to be highly present in ICU patients.
Can some of these parameters be useful in clinical practice to identify the patients at higher risk of having a more severe course of COVID-19?
 W.C. et al., «Risk Factors Associated With Acute Respiratory Distress Syndrome and Death in Patients With Coronavirus Disease 2019 Pneumonia in Wuhan, China. », JAMA Intern Med, Published online March 13, 2020
 «Preliminary Estimates of the Prevalence of Selected Underlying Health Conditions Among Patients with Coronavirus Disease 2019. », United States, February 12–March 28, 2020. MMWR Morb Mortal Wkly Rep 2020;69:382–386.