Data Analysis
The total number of procedures completed in each equivalent time frame were compared to determine the difference between procedure volumes accomplished with proactive cooling and without it. Statistical significance of the increase in rate was assessed assuming that the number of procedures before and after cooling followed the Poisson distribution with equal rate parameters; we used the two-sided level 0.05 exact test implemented via the poisson.test function in R. This function also provided a 95% confidence interval (CI) for the rate ratio.