We have identified four possible red flags, that is, symptoms that increased the probability of COVID‐19 when present because of a positive likelihood ratio of at least 5 in at least one study: fever, myalgia or arthralgia, fatigue, and headache. When we apply the results of sensitivity and specificity of these systemic features to disease probabilities, we assess their value to rule in and rule out disease as shown in the dumbbell plots (Figure 16). These clearly show the limited effect on disease probability from these signs and symptoms. Importantly, we did not find any studies investigating the diagnostic accuracy of combinations of signs and symptoms. There were also no studies from community primary care settings.