Source of missing doses in a decentralized unit dose system: a quality assurance review

Unit dose drug distribution systems have become the prominent drug delivery system in healthcare institutions. Much of the success of the unit-dose concept can be attributed to the increased accountability of medications dispensed and administered. However, as a direct result of this added accountability the problem of "missing doses" has become more evident than under non-unit dose systems. A quality assurance audit was conducted to identify the reasons for missing doses and identify the responsibility for them. A missing dose record was developed through a collaborative effort of the pharmacy and nursing departments. Both staff nurses and pharmacists were invited to review and suggest modifications prior to using the form. All potential reasons for missing dose occurrences were listed on the form. When a missing dose occurred the pharmacist and the nurse completed form jointly to ensure agreement as to the cause. During the 25 day study period the pharmacy dispensed 54,082 doses of medications to patients on the study floors. During that period 227 incidents of missing doses were documented. This resulted in an overall incidence of missing doses of 0.4%. Of the 227 missing doses, a reason for the occurrence was identified for 170 (75%). Nine classes of medications accounted for 62% of all reported missing doses. When responsibility for the missing doses was examined 13.3% were pharmacy generated and 45.8% were nursing generated. The results of the audit generated several suggestions which may decrease the number of missing doses and further improve our drug distribution service.