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Clinical and Epidemiological Characteristics of 1,420 European Patients with mild-to-moderate Coronavirus Disease 2019

Our take —

This study highlights the prevalence and duration of several key symptoms in a moderately sized sample of patients with mild-to-moderate COVID-19 (not requiring admission to ICU). Symptom presentation differed by age and sex. Similar to recent studies, loss of smell was a main symptom, and may be more common among younger patients and females. The results should be interpreted with caution considering some limitations regarding subject selection and exclusion of missing data.

Study design

Case series, Retrospective cohort

Study population and setting

Study includes clinical and demographic data on 1,566 patients (1,420 with full data) with laboratory-confirmed COVID-19 diagnosis who did not require intensive care admission from 18 hospitals in France, Italy, Spain, Belgium, and Sweden. Data were collected via standardized questionnaire between March 22 and April 10, 2020.

Summary of Main Findings

Most patients (94%) were less than 60 years old (mean age 39), and less than 10% required hospitalization (in non-intensive care units). Mean duration of symptoms was 11.5 days (SD 5.7), and the most frequently reported symptoms include: headache (70%), loss of smell (70%), nasal obstruction (68%), cough (63%), asthenia (fatigue, 63%), myalgia (muscle aches, 63%), rhinorrhea (runny nose, 60%), gustatory (taste) dysfunction (54%), and sore throat (53%). Using Bayesian network analysis, the authors report that younger patients more frequently reported symptoms related to ear, nose, and throat, whereas older individuals more often reported fever, fatigue, loss of appetite and diarrhea. Symptom presentation also different by sex; males were more likely to have cough and fever, whereas females more frequently reported loss of smell, headache, nasal obstruction, sore throat, and fatigue.

Study Strengths

This was a moderately large multi-country study using a standardized questionnaire with data on many clinical symptoms and comorbidities.


The study used heterogenous data collection mechanisms (though supposedly the questionnaire was standardized) and did not thoroughly explain the patient selection process, which could lead to inaccuracies in collected information and biased selection of participants, resulting in prevalence estimates that are not representative of all mild-to-moderate COVID-19 cases. The study excluded 146 patients with missing data. It is unclear how long participants were followed up or how the authors defined cure or recovery.

Value added

One of the few studies to examine symptoms and co-morbidities in a large sample of mild-to-moderate COVID-19 cases outside China.