Loymans RJ, Honkoop PJ, Termeer EH, et al. Identifying patients at risk for severe exacerbations of asthma: development and external validation of a multivariable prediction model. Thorax 2016;71:838–46. doi: 10.1136/thoraxjnl-2015-208138

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 follow-up. Discriminative properties of the models were lower in the external validation set (AUROC 0.69 (95% CI 0.63 to 0.75), 0.69 (95% CI 0.63 to 0.75) and 0.69 (95% CI 0.63 to 0.75)) for the three models, respectively (figure 1B).

Page 483: the U-BIOPRED population largely consists of patients with severe asthma and this is reflected in an annual exacerbation risk of about 55% against 13% in the ACCURATE cohort.

Page 844: Predictive properties remained essentially intact on external validation (AUROC 0.69) in a population with more severe asthma and a higher (55%) exacerbation risk.

Corrected figure 1 panel B

Corrected figure 2 panel 1-3B