Minimum Case Volume Recommendations for Complex Surgery—Reply

In Reply I appreciate the Letters to the Editor about our recent Research Letter. Dr Spychalski and colleagues raise concerns about using 30-day mortality rates as the study end point. We intentionally selected the 30-day mortality rate to align with the metrics used in foundational volume-outcome research and by the Leapfrog Group when setting minimum annual volume standards. To ensure comparability between the 2005-2009 and 2015-2019 cohorts, we used the same 30-day end point.