All data are percentages except where mean or median are indicated. Parentheses in the “Prevalence overall” column indicate data from larger or multicentre studies only. All data from individual studies are available in the supplemental Excel file. ^a: A study reported increased dyspnoea during an exacerbation in 77.5% of patients, increased cough during exacerbation in 85.0% of patients and increased sputum purulence and sputum volume in 83.4% and 72.2% of patients, respectively [25]. ^b: Dyspnoea, only when active or exercising, was reported in two studies and ranged from 11.0 to 54.0% [16, 26]. ^c: Single study in adults with noncystic fibrosis bronchiectasis (NCFBE) during a pneumonic or nonpneumonic exacerbation. No significant difference in the prevalence of dyspnoea (p=0.599), cough (p=0.356) or haemoptysis (p=0.422) was reported between pneumonic and nonpneumonic exacerbations [27]. ^d: Single study in children with NCFBE during a virus-positive or virus-negative exacerbation. No significant difference in the prevalence of dyspnoea (p=0.81) or wet cough (p=0.93) was reported between virus-positive and -negative exacerbations; however, virus-negative exacerbations were significantly associated with sputum production (p=0.09) [28]. ^e: The Medical Research Council (MRC) dyspnoea scale assesses the impact of breathlessness on an individual. MRC scores range from 1 to 5, with higher scores indicating more severe dyspnoea [29]. The grading is as follows: 1=not troubled by breathlessness except on strenuous exercise; 2=short of breath when hurrying on a level or when walking up a slight hill; 3=walks slower than most people on the level, stops after a mile or so, or stops after 15 min walking at own pace; 4=stops for breath after walking 100 yards, or after a few minutes on level ground; 5=too breathless to leave the house, or breathless when dressing/undressing. ^f: Studies reporting mean. ^g: Studies reporting median. ^h: Median MRC dyspnoea score reported in a single study of patients admitted to hospital for an exacerbation [30]. In another study, patients hospitalised for an exacerbation during the 1-year follow-up period had significantly higher MRC dyspnoea scores compared with those who were not hospitalised for an exacerbation during the same follow-up period (p=0.004) [31]. ⁱ: Patients with post-tuberculosis (TB) bronchiectasis had significantly higher MRC scores compared with idiopathic bronchiectasis and other aetiologies (not post-TB or idiopathic) (p<0.05 for all comparisons) [32]. ^j: Study reporting in patients with cystic fibrosis (CF)-related bronchiectasis; no comparison with other aetiologies [33]. ^k: The modified MRC (mMRC) dyspnoea scale is a slightly modified version of the MRC dyspnoea scale. mMRC scores range from 0 to 4, with higher scores indicating more severe dyspnoea [34]. Grading is as follows: 0=I only get breathless with strenuous exercise; 1=I get short of breath when hurrying on level ground or walking up a slight hill; 2=on level ground, I walk slower than people of the same age because of breathlessness, or have to stop for breath when walking at my own pace; 3=I stop for breath after walking about 100 yards or after a few minutes on level ground; 4=I am too breathless to leave the house or I am breathless when dressing. ^l: In a single study, the mean mMRC dyspnoea score was significantly higher in frequent exacerbators (≥2 exacerbations per year) compared with nonfrequent exacerbators (p<0.001) [35]. ^m: In a single study, the mean mMRC dyspnoea score was significantly higher in frequent exacerbators (≥2 exacerbations⋅year⁻¹ or ≥1 hospitalisation⋅year⁻¹) compared with nonfrequent exacerbators (p<0.0001) [36]. ⁿ: No statistical analyses performed [19]. “Other” includes rheumatoid arthritis, primary ciliary dyskinesia (PCD), gastro-oesophageal reflux disease and nontuberculous mycobacteria infection. ^o: Studies reporting in patients with idiopathic or post-infectious bronchiectasis; no comparison with other aetiologies [37, 38]. ^p: Patients with PCD-related bronchiectasis had a significantly higher prevalence of cough compared with patients with alpha-1 antitrypsin deficiency (AATD)- and common variable immunodeficiency (CVID)-related bronchiectasis (p=0.012), but not idiopathic bronchiectasis [39]. ^q: Patients with PCD-related bronchiectasis had a significantly higher prevalence of wheezing compared with idiopathic, AATD-associated and CVID-associated bronchiectasis (p<0.0001) [39]. ^r: Single study in adults with NCFBE hospitalised for an exacerbation [40]. ^s: A significantly greater proportion of patients with COPD-related bronchiectasis had daily expectoration compared with other aetiologies (p=0.001) [41]. ^t: In patients admitted to hospital for an exacerbation, significantly more patients with post-TB bronchiectasis had haemoptysis compared with other aetiologies (p=0.006) [30]. ^u: Single study in adults with NCFBE (PCD and primary immunodeficiency excluded) during an exacerbation [25]. ^v: Single study in adults hospitalised for an exacerbation [30]. ^w: In patients admitted to a tertiary care centre; no statistical analyses performed [42]. –: Symptoms for which data were not reported in children, during an exacerbation or in individual aetiologies; ABPA: allergic bronchopulmonary aspergillosis.