In Reply Discrepancies between predicted and observed clinical event risk are a common challenge in cardiovascular medicine not limited to the ASCVD score. Typically, observed event rates are (sometimes significantly) lower than those either predicted by risk prediction instruments or derived from historical cohorts. This phenomenon has been reported in primary prevention cohorts1,2 as well as symptomatic patients3 and constitutes a common issue for power and sample size calculations for clinical trials.
Pursnani A, Massaro JM, Hoffmann U. Predicted vs Observed Clinical Event Risk for Cardiovascular Disease—Reply. JAMA. 2015;314(19):2082-2083. doi:10.1001/jama.2015.12931