Interpretation of nonfatal events after cardiac surgery: Actual versus actuarial reporting

Objective: To describe the cumulative incidence (actual) method of analysis and to contrast it with the Kaplan-Meier method. Method: We use data on porcine valve replacement to illustrate these two statistical techniques. Results: The "actual" analysis estimates the percentage of events expected to occur. The percentage given by the Kaplan-Meier method is much larger. Conclusion: Actual (cumulative incidence) analysis is preferred for estimating the probability of occurrence of a nonfatal time-related event.