Data on the external validation are incorrect; corrections in bold.
Page 838 (Abstract): External validation yielded AUROCs of 0.69 (95% CI 0.63 to 0.75; 0.63 to 0.75 and 0.63 to 0.75) for the three models, respectively; calibration was best for the spirometry model.
Page 840: The three models were validated externally in the Unbiased BIOmarkers in PREDiction of respiratory disease outcomes (U-BIOPRED) data set (n=317), (details in online supplementary appendix I).
Page 841: U-BIOPRED participants had poor asthma symptom control and low lung function; 66.6% had a severe asthma exacerbation in the previous year (see online supplementary table A5 appendix II). The exacerbation risk was higher than in the derivation data set, with 54.9% experiencing a severe exacerbation during 1 year...]]>