Introduction Two quality of life instruments are widely used in bronchiectasis clinical trials, the Quality of Life bronchiectasis questionnaire and the St Georges Respiratory Questionnaire with few large scale multi-centre direct comparisons. Convergent validity represents an assessment of the instrument against other measures that are considered to represent severity of disease, since a valid instrument should agree with clinical assessments of severity of disease and disease burden. We evaluated the convergent validity in the BRONCH-UK dataset. Methods Prospective registry of adults with bronchiectasis from 13 secondary care centres across the UK, embedded within the EMBARC European platform. Patients completed baseline QOL-B and SGRQ and comprehensive clinical assessment. Linear regression and Spearman correlation evaluated the relationship between QOL scores and clinical variables. Results 1403 patients were recruited. We report data on the first 813 with complete core datasets; 504 were female (62%), 309 male (38%). The mean age 65 years SD 12.6. The mean QOL-B RSS was 61 points (SD 22) and mean SGRQ was 42.2 (SD 22) indicating a population with moderate to severe impairment of quality of life There was a strong inverse relationship between the QOL-B respiratory symptom score and the SGRQ (r=-0.74, p<0.0001). Similar relationships were observed across all domains. The QOL-B RSS correlated with FEV1% predicted (r=0.31, p<0.0001), MRC dyspnoea score (r=-0.47, p<0.0001), daily sputum volume (r=-0.46, p<0.0001), exacerbation frequency (r=-0.24, p<0.0001) and the bronchiectasis severity index (r=-0.35, p<0.0001). The SGRQ was correlated with FEV1% predicted (r=-0.32, p<0.0001), MRC dyspnoea score (r=0.55, p<0.0001), daily sputum volume (r=0.42, p<0.0001), exacerbation frequency (r=0.29, p<0.0001) and the BSI (r=0.39, p<0.0001). High risk populations e.g. chronic P. aeruginosa infection and frequent exacerbators (3 or more per year) had higher SGRQ and lower QOL-B RSS scores (p<0.0001 for all comparisons). Conclusion Both the QOL-B RSS and the St Georges Respiratory Questionnaire show acceptable convergent validity in large representative population of patients with bronchiectasis in the UK. Acknowledgements MRC Funding grant MR/L011263/1, Recruiting sites and patients

M26 Convergent Validity of Bronchiectasis Quality of Life Tools in the BRONCH-UK Registry