Cough is a common symptom experienced by nearly every individual in their life and is often a reason for seeking treatment in primary care.

Evidence-based decision making calls for specific knowledge about prevalence, pre-test probabilities, and prognosis in different settings. 

Therefore, researchers from the department of General Practice/Family Medicine, University of Marburg, Germany, conducted a systematic review and meta-analysis of symptom-evaluating studies looking at cough as the cause behind an encounter in primary care.

Authors searched MEDLINE and EMBASE and data was extracted on prevalence, etiologies and prognosis. They estimated the variation across different studies. 

They could find 21 eligible studies on prevalence, 12 on etiology, and 4 on prognosis. The Prevalence/incidence estimates were found to be 3.8–4.2%/12.5% for Western primary care, and 10.3–13.8%/6.3–6.5% in Africa, Asia and South America. 

In the Western world, the underlying diagnoses for cough included:

• Respiratory tract infections - 73–91.9%
• Influenza - 6–15.2%
• Asthma - 3.2–15%
• Laryngitis/tracheitis - 3.6–9%
• Pneumonia - 4.0–4.2%
• COPD - 0.5–3.3%
• Heart failure - 0.3%
• Suspected malignancy - 0.2–1.8%. 

Median time for recovery was 9 to 11 days. Around 40.2-67% of patients reported complete recovery after two weeks, while 79% reported it after four weeks. Nearly 21.1–35% of patients were found to consult again. Additionally, 0-1.3% of patients with acute cough needed hospitalization; none died. 

It was concluded that prevalences and incidences of cough seem to be high and vary by region. Additionally, acute cough, mainly due to respiratory tract infections, is usually self-limiting. However, there is a lack of setting-specific evidence to support guideline recommendations about subacute or chronic cough. 

Reference

Bergmann M, Haasenritter J, Beidatsch D, et al. Prevalence, aetiologies and prognosis of the symptom cough in primary care: a systematic review and meta-analysis. BMC FamPract. 2021; 22: 151.