Characteristics of case and control shifts
| Case shifts (N=41) | Control shifts (N=92) | |
| Age of nurse (SD) | 40.95 (8.69) | 40.35 (5.82) |
| Mean no of shifts 72 h antecedent to index shift | 1.29 | 1.07 |
| No (%) who worked 0, 1, 2, 3 in previous 72 h | ||
| 0 shifts | 9 (22.0%) | 31 (33.7%) |
| 1 shift | 15 (36.6) | 33 (35.9) |
| 2 shifts | 13 (31.7) | 19 (20.7) |
| 3 shifts | 4 (9.76) | 9 (9.78) |
| No (%) who had ≥2 years intensive care unit experience | 27 (66%) | 51 (55%) |
| No (%) of shifts with 1:1 nurse:patient ratio | 40 (98%) | 90 (98%) |