Total number of QREs, number of harm QREs and proportion of harm QREs for each type
| Type | No. (%) of QREs | No. (%) of harm QREs* | Proportion of harm QREs*, % |
|---|---|---|---|
| Incorrect dose or frequency | 25 089 (25.6) | 254 (27.4) | 1.0 |
| Incorrect quantity | 19 619 (20.0) | 19 (2.0) | 0.1 |
| Incorrect drug | 13 951 (14.2) | 185 (19.9) | 1.3 |
| Incorrect strength or concentration | 10 508 (10.7) | 187 (20.2) | 1.8 |
| Incorrect prescriber | 8454 (8.6) | 0 (0) | 0.0 |
| Incorrect patient | 5685 (5.8) | 32 (3.4) | 0.6 |
| Incorrect duration of treatment | 5048 (5.1) | 18 (1.9) | 0.4 |
| Incorrect dosage form or formulation (including not splitting tablets as per patient’s request) | 3281 (3.3) | 32 (3.4) | 1.0 |
| Omitted medication or dose | 1919 (2.0) | 58 (6.23 | 3.0 |
| Incorrect route of administration | 1121 (1.1) | 7 (0.8) | 0.6 |
| Incorrect storage | 857 (0.9) | 3 (0.3) | 0.4 |
| Incorrect third-party billing | 803 (0.8) | 1 (0.1) | 0.1 |
| Drug therapy problem — drug–drug/OTC/natural health product interaction | 506 (0.5) | 19 (2.0) | 3.8 |
| Drug therapy problem — documented allergy | 447 (0.5) | 31 (3.3) | 6.9 |
| Drug therapy problem — contraindication | 356 (0.4) | 12 (1.3) | 3.4 |
| Expired medication | 191 (0.2) | 9 (1.0) | 4.7 |
| Drug therapy problem — adverse drug reaction | 188 (0.2) | 56 (6.0) | 29.8 |
| Drug therapy problem — drug–disease interaction | 63 (0.1) | 3 (0.3) | 4.8 |
| Drug therapy problem — drug–food interaction | 11 (0.0) | 2 (0.2) | 18.2 |
| Total | 98 097 (100) | 928 (100) | – |
Note: OTC = over the counter, QRE = quality-related event.
↵* Harm QREs are associated with a patient outcome of mild harm, moderate harm, severe harm or death (Table 2).