Updated systematic review from Cochrane Infectious Diseases Group: Signs and symptoms to determine if a patient presenting in primary care or hospital outpatient settings has COVID-19 disease.

Updated April 2021: new visual abstract added. 

Can symptoms and medical examination accurately diagnose COVID-19?

COVID-19 affects many organs of the body, so people with COVID-19 may have a wide spectrum of symptoms. Symptoms and signs of the illness may be important to help them and the healthcare staff they come into contact with to know whether they have the disease.

Symptoms: people with mild COVID-19 might experience cough, sore throat, high temperature, diarrhoea, headache, muscle or joint pain, fatigue, and loss or disturbance of sense of smell and taste.

Signs are obtained by clinical examination. Signs of COVID-19 examined in this review include lung sounds, blood pressure, blood oxygen level and heart rate.

Often, people with mild symptoms consult their doctor (general practitioner). People with more severe symptoms might visit a hospital outpatient or emergency department. Depending on the results of a clinical examination, patients may be sent home to isolate, may receive further tests or be hospitalised.

Why is accurate diagnosis important?

Accurate diagnosis ensures that people take measures to avoid transmitting the disease and receive appropriate care. This is important for individuals as it reduces harm and it saves time and resources.

نویسندگان قصد فهمیدن چه چیزی را داشتند؟What did the authors want to find out?

The authors wanted to know how accurate diagnosis of COVID-19 is in a primary care or hospital setting, based on symptoms and signs from medical examination.

They searched for studies that assessed the accuracy of symptoms and signs to diagnose COVID-19. Studies had to be conducted in primary care or hospital outpatient settings only. Studies of people in hospital were only included if symptoms and signs were recorded when they were admitted to the hospital.

Lead author of this updated review Thomas Struyf explains, 

“The total number of studies included has increased and their overall quality has improved compared to the previous version published in July 2020. We also identified more studies focusing on the diagnostic value of loss of smell or taste. 

 This update confirms that a single symptom or sign cannot accurately diagnose COVID-19. However, the presence of the loss of taste or smell may serve as a red flag for the presence of the disease. The presence of high temperature or cough may also be useful to identify people who might have COVID-19. These symptoms may be useful to prompt further testing when they are present.

 We found data on 84 signs and symptoms in 44 studies, but only 10 symptoms were reported by more than 10 studies. So, a lot of these 84 signs and symptoms were not often reported. The top ten most often reported signs and symptoms were fever, cough, shortness of breath, sore throat, muscle soreness, diarrhoea, headache, fatigue, sputum production, and loss of smell or taste.

 Importantly our review did not find a lot of studies that investigated combinations of symptoms. Most studies reported a list of individual symptoms, while diagnosis is usually based on a combination of multiple symptoms. We need more evidence on combinations of signs and symptoms before we could recommend an optimal triage-combination.”

The included studies

The authors found 44 relevant studies with 26,884 participants. The studies assessed 84 separate signs and symptoms, and some assessed combinations of signs and symptoms. Three studies were conducted in primary care (1824 participants), nine in specialist COVID-19 testing clinics (10,717 participants), 12 studies in hospital outpatient settings (5061 participants), seven studies in hospitalised patients (1048 participants), 10 studies in the emergency department (3173 participants), and in three studies the setting was not specified (5061 participants). No studies focused specifically on children, and only one focused on older adults.