Medication errors: an important component of nonadherence to medication in an outpatient population of lung transplant recipients.

Data about medication errors in outpatients are limited. Medication errors, defined as discordance between the most recent flow-sheet version, the patient's diary card or the contents of the pill container were assessed systematically after announcement in an outpatient setting of lung transplant recipients by a direct observation approach. A total of 101 patients took a median of 15 (13-17) different drugs and 31 (26-38) pills daily. A total of 2253 doses of drugs were further analyzed. A total of 152 errors were identified resulting in 303 incorrect doses. Lack of keeping a diary card was the only factor significantly associated with a higher rate of incorrect doses (regression coefficient 0.24, p = 0.02). Furthermore, a significant correlation of medication errors with clinical adverse events could be demonstrated. This study shows that medication errors are frequent in a population which has to comply with a complex drug regimen. The need for error control as a basic requirement for drug adherence must be accentuated. Mostly, medication errors seem to occur system-based. Therefore, redundant error control mechanisms and alertness of both the patient and the care-giver should be initiated systematically.