Table 2.
Baseline characteristics of the population of the included trials.
| Study ID | Interventions | Sample Size | Age Mean (SD) |
Weight (kg) Mean (SD) |
Duration of Surgery (min) Mean (SD) |
Hemoglobin BCS (g/dL) Mean (SD) |
|---|---|---|---|---|---|---|
| Kiabi 2021 [30] | Melatonin | 68 | Between 40 and 20 years | NR | NR | NR |
| 68 | NR | NR | NR | |||
| Placebo | 68 | NR | NR | NR | ||
| Khezri 2019 [29] | Melatonin | 40 | 28.19 (6.21) | 74.75 (6.88) | 81.70 (18.76) | 12.83 (0.94) |
| 40 | 28.38 (5.67) | 72.45 (6.59) | 79.16 (20.11) | 12.68 (0.75) | ||
| Placebo | 40 | 28.63 (5.31) | 75.21 (7.15) | 85.63 (15.70) | 13.2 (0.8) | |
| Khezri 2016 [16] | Melatonin | 40 | 28.19 (6.21) | 74.75 (6.88) | NR | NR |
| 40 | 28.38 (5.67) | 72.45 (6.59) | NR | NR | ||
| Placebo | 40 | 28.63 (5.31) | 75.21 (7.15) | NR | NR | |
| Jayashree 2021 [36] | Melatonin | 30 | NR | NR | NR | 11.02 (0.747) |
| Placebo | 30 | NR | NR | NR | 10.947 (0.564) | |
| Jahromi 2016 [37] | Melatonin | 20 | 30.21 (6.02) | NR | NR | NR |
| Placebo | 20 | 27.72 (4.01) | NR | NR | NR | |
| Gowda 2022 [38] | Melatonin | 30 | NR | NR | NR | 11.26 (0.87) |
| Placebo | 30 | NR | NR | NR | 11.82 (0.92) | |
| Boroojeny 2020 [39] | Melatonin | 50 | 26.2 (4.8) | NR | NR | NR |
| 50 | 26.5 (4.7) | NR | NR | NR | ||
| Placebo | 50 | 26.1 (4.8) | NR | NR | NR |
NR: not reported.