Sex-specific mean values and reference intervals for RET-He, ferritin, reticulocytes, and haemoglobin by age group
| Variables | N | Mean±SD | P2.5 (95% CI) | P97.5 (95% CI) | P value |
| (A) Males (N=497) | |||||
| RET-He (pg) | <0.001 | ||||
| 2–6 | 84 | 29.43±1.52 | 26.41 (25.22 to 27.48) | 32.66 (32.43 to 33.73) | |
| 7–12 | 96 | 29.57±1.64 | 26.28 (25.41 to 26.98) | 32.53 (31.96 to 32.95) | |
| 13–24 | 156 | 30.49±1.47 | 27.30 (26.68 to 28.30) | 33.10 (32.20 to 33.64) | |
| 25–36 | 74 | 30.22±1.41 | 25.95 (23.50 to 26.40) | 32.52 (32.14 to 33.50) | |
| 37–48 | 87 | 30.00±1.21 | 27.22 (26.03 to 27.77) | 31.97 (31.94 to 32.26) | |
| Ferritin (pmol/L) | <0.001 | ||||
| 2–6 | 84 | 187.00±156.01 | 40.15 (26.10 to 53.30) | 500.35 (71.10 to 571.50) | |
| 7–12 | 96 | 107.03±69.06 | 29.00 (18.02 to 36.25) | 312.55 (293.25 to 419.00) | |
| 13–24 | 156 | 108.76±52.68 | 30.75 (19.13 to 39.50) | 238.00 (170.00 to 282.82) | |
| 25–36 | 74 | 139.08±62.54 | 62.65 (53.30 to 71.30) | 308.00 (263.00 to 372.65) | |
| 37–48 | 87 | 161.98±115.79 | 49.63 (33.63 to 61.00) | 441.13 (30.25 to 605.88) | |
| Reticulocytes (×109/L) | 0.023 | ||||
| 2–6 | 84 | 54.52±15.31 | 33.69 (30.68 to 38.43) | 87.93 (67.23 to 102.96) | |
| 7–12 | 96 | 60.08±17.25 | 37.35 (31.30 to 48.70) | 90.35 (29.31 to 103.10) | |
| 13–24 | 156 | 58.88±15.01 | 35.50 (31.90 to 38.70) | 91.25 (82.20 to 99.93) | |
| 25–36 | 74 | 59.31±15.82 | 26.65 (12.93 to 28.99) | 92.83 (84.66 to 104.88) | |
| 37–48 | 87 | 62.89±19.36 | 32.42 (24.45 to 34.15) | 112.89 (108.03 to 134.78) | |
| Haemoglobin (g/L) | <0.001 | ||||
| 2–6 | 84 | 119.5±6.3 | 110.0 (108.9 to 110.0) | 133.0 (130.2 to 136.2) | |
| 7–12 | 96 | 122.6±7.2 | 111.0 (109.0 to 111.6) | 137.0 (134.5 to 141.0) | |
| 13–24 | 156 | 124.6±7.0 | 111.0 (109.0 to 112.0) | 139.1 (136.3 to 142.3) | |
| 25–36 | 74 | 126.7±7.5 | 113.8 (110.7 to 117.7) | 141.9 (137.8 to 146.8) | |
| 37–48 | 87 | 126.1±6.9 | 114.2 (112.3 to 114.3) | 138.9 (130.2 to 141.7) | |
| (B) Females (N=449) | |||||
| Variables | N | Mean±SD | P2.5 (95% CI) | P97.5 (95% CI) | P value |
| RET-He (pg) | <0.001 | ||||
| 2–6 | 83 | 29.66±1.54 | 26.01 (24.49 to 26.49) | 32.10 (29.80 to 32.70) | |
| 7–12 | 88 | 29.54±1.49 | 26.25 (25.11 to 27.08) | 32.05 (31.31 to 32.73) | |
| 13–24 | 133 | 30.78±1.63 | 27.19 (26.15 to 27.88) | 33.71 (32.92 to 34.25) | |
| 25–36 | 60 | 29.78±1.49 | 26.58 (25.16 to 27.75) | 32.35 (32.01 to 33.21) | |
| 37–48 | 85 | 30.16±1.24 | 27.31 (26.57 to 28.27) | 31.90 (30.51 to 32.51) | |
| Ferritin (pmol/L) | <0.001 | ||||
| 2–6 | 83 | 314.46±308.94 | 31.45 (1.13 to 33.85) | 1038.88 (105.28 to 1324.75) | |
| 7–12 | 88 | 122.57±74.12 | 25.70 (15.40 to 32.70) | 300.30 (203.68 to 380.60) | |
| 13–24 | 133 | 110.02±63.60 | 31.90 (23.80 to 45.80) | 258.30 (107.60 to 315.00) | |
| 25–36 | 60 | 165.70±103.91 | 52.33 (22.80 to 61.65) | 470.45 (284.90 to 698.68) | |
| 37–48 | 85 | 154.96±72.12 | 54.83 (29.83 to 62.65) | 340.25 (224.43 to 417.50) | |
| Reticulocytes (×109/L) | 0.086 | ||||
| 2–6 | 83 | 62.52±14.05 | 35.79 (29.07 to 37.44) | 86.10 (71.53 to 89.60) | |
| 7–12 | 88 | 64.17±16.20 | 39.82 (35.97 to 40.59) | 100.77 (76.09 to 116.24) | |
| 13–24 | 133 | 65.58±15.89 | 40.07 (35.35 to 45.24) | 96.18 (84.16 to 101.26) | |
| 25–36 | 60 | 70.16±22.64 | 32.49 (22.37 to 47.17) | 129.25 (126.80 to 162.91) | |
| 37–48 | 85 | 63.33±18.83 | 32.99 (24.69 to 48.51) | 103.79 (81.98 to 120.65) | |
| Haemoglobin (g/L) | <0.001 | ||||
| 2–6 | 83 | 119.8±6.6 | 111.0 (110.0 to 112.0) | 134.0 (130.9 to 138.0) | |
| 7–12 | 88 | 121.1±6.8 | 111.0 (109.8 to 112.0) | 134.0 (133.2 to 136.0) | |
| 13–24 | 133 | 123.4±6.6 | 113.0 (112.0 to 115.0) | 136.7 (134.4 to 139.3) | |
| 25–36 | 60 | 125.5±7.0 | 112.4 (107.8 to 114.8) | 138.0 (133.0 to 140.0) | |
| 37–48 | 85 | 127.3±7.2 | 115.1 (112.1 to 119.7) | 140.6 (128.0 to 144.4) |
Males (N=497) Females (N=449).
RET-He, reticulocyte haemoglobin equivalent.