Data are presented as n (%) or mean±sd, unless otherwise stated. Data are presented from time of entry into the cohort. PSA: Pseudomonas aeruginosa; CT: computed tomography; LF: lung function; Bx: bronchiectasis; % pred: % predicted; FEV₁: forced expiratory volume in 1 s; FVC: forced vital capacity; RV: residual volume; TLC: total lung capacity; T_L,CO: transfer factor of the lung for carbon monoxide; K_CO: transfer coefficient of the lung for carbon monoxide; MRC: Medical Research Council; SGRQ: St George’s Respiratory Questionnaire; ABPA: allergic bronchopulmonary aspergillosis; PCD: primary ciliary dyskinesia. ^#: from recruitment until March 1, 2007, or until patient died; ^¶: expressed as a percentage of the maximal possible score for each criterion; ⁺: range 1–5, with a score of 1 representing greatest breathlessness on strenuous exercise; ^§: range 0–100, with a zero score indicating no impairment in quality of life.