Characteristics of studies included
| Type of hospital | |
| Academic/tertiary referral centre=24 | |
| Community=1 | |
| Mixed=1 | |
| Unspecified=3 | |
| Country of origin | Type of ICU studied |
| USA=17 | Medical ICU=2 |
| UK=4 | Surgical ICU=1 |
| Australia=1 | Paediatric ICU=4 |
| Canada=2 | Neonatal ICU=1 |
| Other=5 | Mixed ICU=6 |
| Other=2 | |
| >1 of above=11 | |
| Unspecified=2 | |
| No of centres in each study | Length of study |
| 1=22 | ≤1 month=9 |
| 2=3 | >1–12 months=14 |
| ≥3=4 | >1 year=6 |
| Method of error detection | No of ICU beds studied |
| Observation=6 | 1–10=2 |
| Prescription review=7 | 11–20=10 |
| Multifaceted=7 | 21–30=3 |
| Voluntary reporting=5 | >30=7 |
| Trigger tool=3 | Unspecified=7 |
| Two methods compared=1 | |
ICU, intensive care unit.