We read the letter of Chhabra and Spodick commenting on our report. Their comments and especially their brief analysis of the disparities in the findings of past studies on postoperative atrial fibrillation (POAF) are, in our opinion, insightful and to the point.

We are happy to provide our own findings, although we are not sure whether they can elucidate this issue much further: we did not include these in our original article because our study was not powered to detect differences in atrial fibrillation incidence and, as a result, reporting lack of statistical significance in the observed rates of POAF may be misleading. Indeed, there was a substantial arithmetical difference in the number of patients with POAF, but this was not statistically significant. In particular, 5 of 30 patients in the colchicine group and 10 of 29 controls had POAF (16.7% vs 34.5%, respectively; p = 0.116), corresponding to an odds ratio of 0.38 (95% confidence interval 0.11 to 1.30). Obviously, as already pointed out, the lack of statistical significance in this case may simply reflect that the study was underpowered for this end point.

In regard to patient compliance, we have found, both in this and in our previous studies, that some simple measures, such as taking colchicine with food and reducing the daily dose to 0.5 mg in patients with body weight <60 kg, may significantly reduce gastrointestinal complaints and increase adherence.