Table 4. Number of medication errors and adverse drug event (ADE) rates at Brigham and Women's Hospital before and after introduction of a computer-based physician order entry Reducing and Preventing Adverse Drug Events To Decrease Hospital Costs Medication errors (other than missed dose errors)Baseline: 242 (142)Period 1: 134 (51.2)Period 2: 132 (74.0)Period 3: 50 (26.6)Dose errorsBaseline: 81 (47.5)Period 1: 90(a) (34.3)Period 2: 114(a) (63.9)Period 3: 40(a) (21.3)Frequency errorsBaseline: 43 (25.2)Period 1: 4 (1.5)Period 2: 2 (1.1)Period 3: 4 (2.1)Route errorsBaseline: 25 (14.7)Period 1: 5 (1.9)Period 2: 6 (3.3)Period 3: 4 (2.1)Substitution errorsBaseline: 12 (7.0)Period 1: 3 (1.1)Period 2: 3 (1.7)Period 3: 0 (0)Documented allergyBaseline: 10 (5.9)Period 1: 1 (0.4)Period 2: 1 (0.6)Period 3: 0 (0)Inappropriate drugBaseline: 7 (4.1)Period 1: 3 (1.1)Period 2: 1 (0.6)Period 3: 0 (0)Avoidable delayBaseline: 7 (4.1)Period 1: 0 (0)Period 2: 0 (0)Period 3: 0 (0)Drug-drug interactionBaseline: 2 (1.2)Period 1: 0 (0)Period 2: 1 (0.6)Period 3: 0 (0)Inadequate followupBaseline: 1 (0.6)Period 1: 0 (0)Period 2: 0 (0)Period 3: 0 (0)OtherBaseline: 54 (31.7)Period 1: 28 (10.7)Period 2: 4 (2.2)Period 3: 2 (1.1)Total ADEsBaseline: 25 (14.7)Period 1: 39 (14.9)Period 2: 19 (10.7)Period 3: 18 (9.6)Intercepted potential ADEsBaseline: 27 (15.8)Period 1: 82(a) (31.3)Period 2: 106(a) (59.4)Period 3: 1 (0.5)Non-intercepted potential ADEsBaseline: 8 (4.7)Period 1: 4 (1.5)Period 2: 1 (0.6)Period 3: 0 (0)Note: The figure in parentheses indicates the rate per 1,000 patient days. (a) Seventy-seven dose errors in period 1 and 101 in period 2 were due to potassium chloride errors; none of 40 dose errors in period 3 were due to potassium chloride error. After revising potassium chloride ordering screens, these errors were eliminated.Source: Bates DW, Teich JM, Lee J, et al. The impact of computerized physician order entry on medication error prevention. J Am Inform Assoc 1999;6(4):313-21.Return to Document Current as of March 2001 Internet Citation: Table 4. Number of medication errors and adverse drug event (ADE) rates at Brigham and Women's Hospital before and after introduction of a computer-based physician order entry: Reducing and Preventing Adverse Drug Events To Decrease Hospital Costs. March 2001. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/research/findings/factsheets/errors-safety/aderia/table4.html