What proportion of vancomycin trough levels are drawn too early?: frequency and impact on clinical actions.

Vancomycin trough levels are recommended to predict vancomycin efficacy, and inaccurate levels may lead to inappropriate clinical actions. However, the frequency of timing errors and associated clinical impact is unknown. We retrospectively analyzed vancomycin levels (n = 2,597) measured during 13 months at a large academic medical center. Of the specimens, 41.3% were drawn too early. These samples yielded significantly higher average ± SD vancomycin concentrations than correctly timed samples (22.1 ± 11.7 mg/L vs 15.5 mg/L ± 8.6 mg/L; P < .001), and, consequently, clinicians were more likely to decrease, discontinue, or hold a patient's vancomycin dose (25.6% vs 21.4%; P < .02) or repeat the vancomycin level (29.2% vs 20.0%; P < .001). A substantial proportion of specimens collected to assess vancomycin efficacy were drawn too early, leading to overestimation of patients' true trough level and possible underdosing of vancomycin or a high rate of repeat tests for vancomycin.

Effect of an electronic medication reconciliation application and process redesign on potential adverse drug events: a cluster-randomized trial.

BACKGROUND: Medication reconciliation at transitions in care is a national patient safety goal, but its effects on important patient outcomes require further evaluation. We sought to measure the impact of an information technology-based medication reconciliation intervention on medication discrepancies with potential for harm (potential adverse drug events [PADEs]). METHODS: We performed a controlled trial, randomized by medical team, on general medical inpatient units at 2 academic hospitals from May to June 2006. We enrolled 322 patients admitted to 14 medical teams, for whom a medication history could be obtained before discharge. The intervention was a computerized medication reconciliation tool and process redesign involving physicians, nurses, and pharmacists. The main outcome was unintentional discrepancies between preadmission medications and admission or discharge medications that had potential for harm (PADEs). RESULTS: Among 160 control patients, there were 230 PADEs (1.44 per patient), while among 162 intervention patients there were 170 PADEs (1.05 per patient) (adjusted relative risk [ARR], 0.72; 95% confidence interval [CI], 0.52-0.99). A significant benefit was found at hospital 1 (ARR, 0.60; 95% CI, 0.38-0.97) but not at hospital 2 (ARR, 0.87; 95% CI, 0.57-1.32) (P = .32 for test of effect modification). Hospitals differed in the extent of integration of the medication reconciliation tool into computerized provider order entry applications at discharge. CONCLUSIONS: A computerized medication reconciliation tool and process redesign were associated with a decrease in unintentional medication discrepancies with potential for patient harm. Software integration issues are likely important for successful implementation of computerized medication reconciliation tools.

Classifying and predicting errors of inpatient medication reconciliation.

BACKGROUND: Failure to reconcile medications across transitions in care is an important source of potential harm to patients. Little is known about the predictors of unintentional medication discrepancies and how, when, and where they occur. OBJECTIVE: To determine the reasons, timing, and predictors of potentially harmful medication discrepancies. DESIGN: Prospective observational study. PATIENTS: Admitted general medical patients. MEASUREMENTS: Study pharmacists took gold-standard medication histories and compared them with medical teams' medication histories, admission and discharge orders. Blinded teams of physicians adjudicated all unexplained discrepancies using a modification of an existing typology. The main outcome was the number of potentially harmful unintentional medication discrepancies per patient (potential adverse drug events or PADEs). RESULTS: Among 180 patients, 2066 medication discrepancies were identified, and 257 (12%) were unintentional and had potential for harm (1.4 per patient). Of these, 186 (72%) were due to errors taking the preadmission medication history, while 68 (26%) were due to errors reconciling the medication history with discharge orders. Most PADEs occurred at discharge (75%). In multivariable analyses, low patient understanding of preadmission medications, number of medication changes from preadmission to discharge, and medication history taken by an intern were associated with PADEs. CONCLUSIONS: Unintentional medication discrepancies are common and more often due to errors taking an accurate medication history than errors reconciling this history with patient orders. Focusing on accurate medication histories, on potential medication errors at discharge, and on identifying high-risk patients for more intensive interventions may improve medication safety during and after hospitalization.