In Reply We thank Kim et al for their interest in our study. We fully agree that replicating and validating study findings in independent data sets is of major importance for the credibility and generalizability of the results.
We are therefore very pleased to read that Kim et al confirmed our finding of an increased risk of malignant cancer among individuals with atrial fibrillation. They also confirmed that the risk was highest shortly after new-onset atrial fibrillation but remained significant over the long term. We hope that these data stimulate more studies to evaluate the underlying mechanisms of this association.