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 system*


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 errors
Baseline: 81 (47.5)
Period 1: 90(a) (34.3)
Period 2: 114(a) (63.9)
Period 3: 40(a) (21.3)

Frequency errors
Baseline: 43 (25.2)
Period 1: 4 (1.5)
Period 2: 2 (1.1)
Period 3: 4 (2.1)

Route errors
Baseline: 25 (14.7)
Period 1: 5 (1.9)
Period 2: 6 (3.3)
Period 3: 4 (2.1)

Substitution errors
Baseline: 12 (7.0)
Period 1: 3 (1.1)
Period 2: 3 (1.7)
Period 3: 0 (0)

Documented allergy
Baseline: 10 (5.9)
Period 1: 1 (0.4)
Period 2: 1 (0.6)
Period 3: 0 (0)

Inappropriate drug
Baseline: 7 (4.1)
Period 1: 3 (1.1)
Period 2: 1 (0.6)
Period 3: 0 (0)

Avoidable delay
Baseline: 7 (4.1)
Period 1: 0 (0)
Period 2: 0 (0)
Period 3: 0 (0)

Drug-drug interaction
Baseline: 2 (1.2)
Period 1: 0 (0)
Period 2: 1 (0.6)
Period 3: 0 (0)

Inadequate followup
Baseline: 1 (0.6)
Period 1: 0 (0)
Period 2: 0 (0)
Period 3: 0 (0)

Other
Baseline: 54 (31.7)
Period 1: 28 (10.7)
Period 2: 4 (2.2)
Period 3: 2 (1.1)

Total ADEs
Baseline: 25 (14.7)
Period 1: 39 (14.9)
Period 2: 19 (10.7)
Period 3: 18 (9.6)

Intercepted potential ADEs
Baseline: 27 (15.8)
Period 1: 82(a) (31.3)
Period 2: 106(a) (59.4)
Period 3: 1 (0.5)

Non-intercepted potential ADEs
Baseline: 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