A nurse arrives for her shift and is preparing to count the controlled substances in the secure cabinet. Which of the following actions should the nurse take?

Controlled substance counts at shift change require the incoming nurse to verify that the physical count of each medication matches the quantity recorded on the inventory record. This reconciliation process detects discrepancies that could indicate diversion, documentation errors, or theft, which is why the counts must be witnessed and signed by two nurses simultaneously. Discarding partial doses in a sharps container is incorrect because controlled substance waste must be witnessed and documented by a second licensed nurse before disposal, and sharps containers are not the appropriate mechanism for controlled substance waste. Setting aside medications planned for use during the shift is inappropriate because controlled substances must remain locked until the time of administration to prevent diversion or access by unauthorized individuals. Co-signing wasted doses from the previous shift at the time of the count is incorrect practice; waste documentation must be co-signed at the time the waste occurs, not hours later during the next shift's count, as a delayed co-signature cannot verify that the wasting actually happened as recorded. The correct action — matching counts to the inventory record — is the foundational step in controlled substance accountability.