Intention To Treat Principle Alternative Concepts And Sensitivity Analyses In Orthopedics

This article provides an overview of the concepts of intention to treat (ITT, patients are evaluated as they were randomized), per protocol (PP, patients not treated according to the protocol are excluded from the analysis), and as treated (AT, patients are evaluated under the treatment they actually received) for randomized controlled clinical trials (RCT) in orthopedics. An ITT analysis should ensure the maintenance of the advantages of a random treatment allocation for the comparability of the treatment groups with respect to known and unknown influencing factors; however, if the protocol is violated the treatment effect can be weakened so that additional PP or AT analyses are useful for a clearer assessment of the treatment effect. The result of an RCT can be checked for robustness by applying all three principles and thus used as sensitivity analyses.