Statistical methods for primary and secondary outcomes {20a}
All details of statistical analyses will be specified in the statistical analysis plan, which will be finalised before the inclusion of the last patient. The primary and other efficacy endpoints will be analysed in the full analysis population. Patients who died before the 5-year follow-up and patients who were not able to complete the lung function test will be excluded from the full analysis set. The primary endpoint will be tested in a generalised estimating equation model assuming Gaussian error and exchangeable correlation matrix using a two-sided Wald test at a significance level alpha of 0.05.