Erratum: "Drivers of year-to-year variation in exacerbation frequency of COPD: analysis of the AERIS cohort" Tom M.A. Wilkinson, Emmanuel Aris, Simon C. Bourne, Stuart C. Clarke, Mathieu Peeters, Thierry G. Pascal, Laura Taddei, Andrew C. Tuck, Viktoriya L. Kim, Kristoffer K. Ostridge, Karl J. Staples, Nicholas P. Williams, Anthony P. Williams, Stephen A. Wootton and Jeanne-Marie Devaster, on behalf of the AERIS Study Group. ERJ Open Res 2019; 5: 00248-2018