Training was implemented to ensure reliability across data collectors for performing HFCWO and CPT treatment. Interrater reliability was measured at baseline and quarterly during the course of the study. Two advanced practice nurses with combined experience in critical care and cardiology evaluated video recordings of registered nurses performing CPT and graded each nurse by using a competency scoring sheet. Interrater reliability was randomly evaluated among 10% of the recordings, with at least 90% agreement achieved.