Overall and preventable adverse event rates for 2009 and 2015, presented by category of adverse event
| Category of adverse event | Percentage of adverse events in this category in 2009 (95% CI) | Percentage of adverse events in this category in 2015 (95% CI) | OR comparing the percentage of adverse events in this category in 2009–2015 | P value | Percentage of preventable adverse events in this category in 2009 (95% CI) | Percentage of preventable adverse events in this category in 2015 (95% CI) | OR comparing the percentage of preventable adverse events in this category in 2009–2015 | P value |
| Categories of adverse events thought to be targeted by the national programmes and guidelines | ||||||||
| Hospital associated infections related* | 32.6 (26.4 to 39.4) | 23.6 (17.7 to 30.6) | 0.6 (0.4 to 0.9) | 0.02 | 33.1 (25.6 to 41.6) | 22.2 (15.2 to 31) | 0.6 (0.4 to 0.9) | 0.02 |
| Surgical related (related to the perioperative phase of treatment)† | 32.9 (20.9 to 47.5) | 28.3 (20.2 to 38.1) | 0.8 (0.5 to 1.4) | 0.44 | 27.1 (17.5 to 39.4) | 24.2 (15 to 36.3) | 0.9 (0.4 to 1.7) | 0.6 |
| Drug related (drug reactions, side effects, rashes)† | 19.1 (13.3 to 26.6) | 25.3 (18.4 to 33.8) | 1.4 (0.9 to 2.3) | 0.13 | 18.3 (11.3 to 28.3) | 15.6 (10 to 23.4) | 0.8 (0.4 to 1.6) | 0.6 |
| Fracture related (injuries occurring in the perioperative phase, pertaining to fracture presentation)† | 5.1 (3.2 to 8) | 3.7 (1.8 to 7.6) | 0.7 (0.3 to 1.8) | 0.46 | 5.5 (2.7 to 11.1) | 3.5 (1.7 to 7.2) | 0.6 (0.2 to 1.9) | 0.4 |
| Methicillin-resistant Staphylococcus aureus related* | 6 (3.1 to 11.4) | 3.1 (1.6 to 5.8) | 0.5 (0.2 to 1.3) | 0.13 | 8.3 (4.6 to 14.7) | 5.4 (2.6 to 11.1) | 0.6 (0.2 to 1.7) | 0.3 |
| Clostridium difficile related* | 3.9 (1.3 to 10.7) | 1.5 (0.2 to 10.6) | 0.4 (0 to 4.3) | 0.4 | 5.2 (1.9 to 13.3) | 2.4 (0.3 to 17.1) | 0.5 (0 to 5.6) | 0.5 |
| Anaesthetic related (as a result of an anaesthetic drug or procedure)† | 1.5 (0.1 to 4.5) | 1.2 (0.6 to 2.3) | 0.8 (0.2 to 3.6) | 0.77 | 0.2 (0 to 1.1) | 1.2 (0.5 to 2.6) | 5.1 (0.7 to 39.8) | 0.1 |
| Categories of adverse events which were not targeted by the national programmes and guidelines | ||||||||
| Therapeutic related (due to lack of monitoring including nursing care)† | 31.7 (20.6 to 45.3) | 27.1 (19.2 to 36.6) | 0.8 (0.4 to 1.8) | 0.55 | 41.7 (31.1 to 52.3) | 35.7 (23.6 to 50) | 0.8 (0.4 to 1.7) | 0.5 |
| Diagnostic related (failure to make correct diagnosis or underestimate severity of presentation)† | 14.9 (10.3 to 21.1) | 15.4 (11.9 to 19.7) | 1.04 (0.6 to 1.7) | 0.9 | 20.5 (15.5 to 26.5) | 26.3 (20.2 to 33.3) | 1.4 (0.8 to 2.4) | 0.2 |
| Other not covered (injuries not fitting into other categories, eg, falls)† | 11.9 (7.1 to 19.4) | 5.6 (3.2 to 9.9) | 0.4 (0.2 to 1.1) | 0.07 | 14.4 (8.6 to 23) | 7.9 (4.4 to 13.4) | 0.5 (0.2 to 1.4) | 0.2 |
| **Medical procedure related (related to non-surgical intervention PICC line insertion, colonoscopy, catheters)† | 10.2 (5.1 to 19.4) | 14.5 (9.8 to 20.8) | 1.5 (0.7 to 3.4) | 0.32 | 8.1 (2.6 to 22.2) | 10.9 (7.8 to 50.1) | 1.4 (0.5 to 4.3) | 0.5 |
| Obstetric related (any incident occurring in a pregnant woman)† | 1.5 (0 to 10.9) | N/A | N/A | NA | 2.1 (0.3 to 14.2) | N/A | N/A | N/A |
P values were derived using logistic regression (see Methods section). It is possible for each adverse event to be classified into one or more categories.
*Category of adverse event created to reflect the national programmes and guidelines.
†Category of adverse event historically used in studies using the Harvard Medical Practice Study methodology of adverse event detection (including the original INAES study).
INAES, Irish National Adverse Event Study; PICC, Peripherally Inserted Central Catheter.