Prescribing errors according to the stage of the drug use process
| Stage of prescribing process | Pre-intervention, number of errors (% of total orders) | Post-intervention, number of errors (% of total orders) | RRR (%) | ARR (%) | χ2, OR (95% CI)* |
| Prescribing decision errors | |||||
| Total orders | 9772 | 10 352 | |||
| Need for a drug (duplication) | 64 (0.65) | 48 (0.46) | – | – | p = 0.068, 0.71 (0.49 to 1.03) |
| Drug selection (previous ADR) | 21 (0.21) | 9 (0.08) | 61.9 | 0.13 | p = 0.027, 0.4 (0.19 to 0.88) |
| Dose (including dose frequency) selection | 61 (0.62) | 52 (0.50) | – | – | p = 0.247, 0.8 (0.56 to 1.17) |
| Sustained release form specified | 29 (0.29) | 47 (0.45) | – | – | p = 0.085; OR 1.53 (0.96 to 2.44) |
| All prescribing decision (drug selection) errors | 175 | 156 | |||
| Administration and supply written instruction errors | |||||
| Drug name | 151 (1.54) | 116 (1.12) | 28.6 | 0.44 | p = 0.009, 0.722 (0.57 to 0.92) |
| Dose (all orders) | 302 (3.09) | 254 (2.45) | 20.7 | 0.64 | p = 0.006, 0.79 (0.67 to 0.93) |
| Frequency (regular) | 955 (15.91) (pre = 6001 orders) | 710 (10.98) (post = 6464 orders) | 30.9 | 4.93 | p<0.001, 0.65 (0.59 to 0.72) |
| Frequency (as Required) -all errors | 717 (34.32) (pre = 2089 orders) | 699 (34.23) (post = 2046 order) | – | – | p = 0.785, 0.98 (0.86 to 1.12) |
| Frequency (as required)—missing | 140 (6.71) (pre = 2089 orders) | 214 (10.45) (post = 2046 orders) | 55.7 | 3.74 | p<0.001, 1.63 (1.3 to 2.0) |
| Frequency (as required)—unclear | 577 (27.62) (pre = 2089 orders) | 485 (23.70) (post = 2046 orders) | 14.1 | 3.92 | p = 0.004, 0.81 (0.71 to 0.94) |
| All prescribing instruction errors | 2125 | 1779 |
ARR, absolute risk reduction; OR, odds ratiol RRR, relative risk reduction.