Table 2. Subgroup analyses for studies evaluating the effects of early nutrition and delayed nutrition on mortality.
| Subgroups | N | RR (95% CI) | Heterogeneity (I2) |
| Total | 7 | 0.35 (0.24, 0.50) | 44% |
| Sample size | |||
| <100 | 5 | 0.49 (0.27, 0.87) | 30% |
| >100 | 2 | 0.28 (0.22, 0.35) | 0 |
| Publication year | |||
| <2005 | 3 | 0.54 (0.23, 1.27) | 35% |
| >2005 | 4 | 0.29 (0.23, 0.37) | 6% |
| Study design | |||
| RCT | 4 | 0.62 (0.32, 1.22) | 14% |
| NPS | 3 | 0.28 (0.23, 0.35) | 0 |
| Starting time of early nutrition | |||
| <72 h | 5 | 0.45 (0.24, 0.87) | 56% |
| <7 d | 2 | 0.26 (0.18, 0.39) | 0 |
| Compared route | |||
| Early PN vs. delayed EN | 2 | 0.57 (0.19, 1.76) | 62% |
| Early EN vs. delayed EN | 3 | 0.37 (0.21, 0.68) | 0 |
| Early EN vs. no feeding | 1 | 0.29 (0.22, 0.38) | - |
| Unknown | 1 | 0.24 (0.15, 0.38) | - |
Abbreviations: EN, enteral nutrition; N, number of studies; NPS, non-randomized prospective study; PN, parenteral nutrition; RCT, randomized controlled trial; RR, relative risk.