Studies of the symptom dyspnoea: a systematic review

To deal with patients suffering from dyspnoea, it is crucial for general practitioners to know the prevalences of different diseases causing dyspnoea in the respective area and season, the likelihood of avoidable life-threatening conditions and of worsening or recovery from disease.

Aim of our project was to conduct a systematic review of symptom-evaluating studies on the prevalence, aetiology, and prognosis of dyspnoea as presented to GPs in a primary care setting.

We did a systematic review of symptom-evaluating studies on dyspnoea in primary care. For this we included all studies investigating the complaint "dyspnoea" as a primary or secondary consulting reason in general practice. Apart from qualitative studies, all kind of study designs independent from type of data assessment, outcome measurement or study quality were included. Symptom-evaluating studies from other settings than primary care and studies which exclusively included children (age <18 years) were excluded from the review. Studies selecting patients prior to recruitment, e.g. because of an increased probability for a particular diagnosis, were also excluded.

This systematic review identified 6 symptom evaluating studies on dyspnoea in the primary care setting. The prevalence of dyspnoea as reason for consultation ranges from 0.87 to 2.59 % in general practice. Among all dyspnoea patients 2.7 % (CI 2.2-3.3) suffer from pneumonia. Further specification of underlying aetiologies seems difficult due to the studies' heterogeneity showing a great variety of probabilities.

There is a great lack of empirical evidence on the prevalence, aetiology and prognosis of dyspnoea in general practice. This might yield uncertainty in diagnosis and evaluation of dyspnoea in primary care.