Fig. 4

Forest plot: Prevalences of selected aetiologies in patients with cough of all durations. Estimates refer to primary care patients of all age groups in consultation for cough of all durations. Denominators: Consultations (NAMCS Metlay 1998), episodes of care (TRANSITION Okkes 2002), incidental consultations (Morrell 1972), reasons for encounter (CONTENT Laux 2007, SESAM Frese 2008), patients (Woolnough 1985). * = studies included adults only, CI = confidence interval, COPD = Chronic obstructive pulmonary disease, k = number of patients with the respective aetiology, N = total number of patients in consultation for cough