No Single Sign or Symptom Can Rule Out Community-Acquired Pneumonia

No single sign or symptom is enough to rule out community-acquired pneumonia (CAP), according to a new study published in Academic Emergency Medicine.

CAP is an important source of morbidity and mortality, according to the study. The history and physical examination are a crucial part in the evaluation of patients with acute cough to identify CAP. However, the overtreatment of acute cough illness with antibiotics is also an important problem. Improved diagnosis of CAP can help reduce inappropriate antibiotic use, according to the study.

The study was a meta-analysis of productive cohort studies of patients with clinically suspected pneumonia or acute cough that used imaging as the reference standard. The studies were reviewed in parallel by 2 researchers with quality being assessed using the QUADAS-2 criteria. Out of the 17 studies identified, 12 were judged to be at low risk of bias. The other 5 were judged to be at a moderate risk of bias.

The study found that the prevalence of CAP in primary care studies was 10% and 20% in emergency department studies, respectively. The probability of CAP was found to increase most by an abnormal clinical impression suggestion CAP, egophony, dullness to percussion, and measured temperature, according to the study. On the other hand, the probability of CAP decreased the most by the absence of abnormal vital signs. According to the study, most individual signs and symptoms were unhelpful in the diagnosis of CAP.

“Based on the comparison of subjective with objective temperature, one concludes that the absence of subjective fever helps rule out CAP, while the presence of measured fever tends to rule it in. However, the converse (absence of measured fever or presence of subjective fever) is less helpful diagnostically,” the study states.

Strengths of the study included comprehensive literature research, the use of contemporary bivariate meta-analysis, and the good methodologic quality of included studies. Weaknesses included differences in the inclusion data and the failure to define what is an abnormal sign or symptom.

Reference:

Ebell, Mark H. Accuracy of Signs and Symptoms for the Diagnosis of Community‐acquired Pneumonia: A Meta‐analysis (Study), Athens, GA, July 2020 Wiley Online Library, accessed July 22, 2020