Table 2

Age and sex-specific reference intervals for analytes (after excluding outliers)

Haemoglobin, g/L
Age group MaleFemale
NLower limit
(90% CI)
Upper limit
(90% CI)
NLower limit
(90% CI)
Upper limit
(90% CI)
 10 days to <1 year28899 (97 to 100)133 (132 to 134)237100 (99 to 102)132 (130 to 133)
 >1 to <3 years815101 (100 to 103)133 (132 to 134)707102 (100 to 104)134 (134 to 135)
 >3 to <6 years979107 (106 to 108)135 (134 to 136)844108 (107 to 109)136 (135 to 136)
 ≥6 to 10 years422111 (108 to 112)140 (139 to 141)355110 (109 to 111)140 (139 to 141)
Mean corpuscular volume, fL
 10 days to <1 year27568 (65 to 70)86 (84 to 88)23072 (71 to 73)86 (85 to 86)
 >1 to <3 years81467 (66 to 68)83 (82 to 83)68769 (68 to 70)83 (83 to 84)
 >3 to <6 years97473 (72 to 73)84 (84 to 85)84473 (72 to 74)86 (85 to 86)
 ≥6 to 10 years41575 (75 to 76)87 (86 to 87)34277 (75 to 77)87 (86 to 88)
C-reactive protein, mg/L
 10 days to <1 year2960.09 (0.09 to 0.09)6.10 (5.50 to 9.00)2430.09 (0.09 to 0.09)4.70 (2.90 to 5.10)
 >1 to <3 years10010.04 (0.03 to 0.04)3.091 (2.79 to 3.42)8960.09 (0.09 to 0.09)7.30 (5.80 to 9.40)
 >3 to <6 years11950.043 (0.04 to 0.05)3.00 (2.75 to 3.28)10730.05 (0.05 to 0.06)3.50 (3.18 to 3.84)
 ≥6 to 10 years4060.09 (0.09 to 0.09)3.60 (2.70 to 4.10)3460.09 (0.09 to 0.09)4.90 (4.00 to 8.90)
Serum ferritin, µg/L
 10 days to <1 year2669 (9 to 10)115 (99 to 139)23310 (8 to 11)194 (157 to 271)
 >1 to <3 years9096 (5 to 6)70 (65 to 79)8177 (6 to 8)81 (75 to 89)
 >3 to <6 years106912 (11 to 12)71 (68 to 74)94912 (11 to 12)74 (71 to 81)
 ≥6 to 10 years41115 (13 to 15)81 (71 to 87)35313 (10 to 15)92 (83 to 109)
Iron, µmol/L
 10 days to <1 year2543 (2 to 4)20 (18 to 21)1864 (3 to 5)19 (17 to 20)
 >1 to <3 years7864 (4 to 4)21 (20 to 22)7054 (3 to 4)23 (21 to 23)
 >3 to <6 years9474 (4 to 5)25 (23 to 26)8614 (4 to 4)24 (23 to 25)
 ≥6 to 10 years2935 (4 to 5)25 (24 to 27)2514 (3 to 5)24 (23 to 26)
Transferrin, g/L
 10 days to <1 year2482.01 (1.95 to 2.08)3.49 (3.40 to 3.54)1861.99 (1.92 to 2.06)3.35 (3.28 to 3.43)
 >1 to <3 years7652.32 (2.30 to 2.37)3.80 (3.78 to 3.94)6692.30 (2.25 to 2.30)3.70 (3.68 to 3.80)
 >3 to <6 years9252.20 (2.20 to 2.27)3.45 (3.40 to 3.50)8412.28 (2.20 to 2.30)3.40 (3.39 to 3.46)
 ≥6 to 10 years2922.20 (2.17 to 2.28)3.60 (3.40 to 3.64)2492.25 (2.15 to 2.35)3.35 (3.30 to 3.42)
White blood cells, ×109/L
 10 days to <1 year2936.51 (6.06 to 6.71)17.0 (15.22 to 18.05)2365.81 (5.21 to 6.50)16.02 (15.38 to 16.61)
 >1 to <3 years8245.51 (5.14 to 5.89)15.7 (15.1 to 16.1)7065.90 (5.42 to 6.00)15.4 (14.8 to 15.9)
 >3 to <6 years9884.59 (4.39 to 4.76)12.9 (12.42 to 13.79)8594.70 (4.31 to 4.86)12.7 (12.4 to 13.5)
 ≥6 to 10 years4204.47 (3.94 to 4.64)12.0 (11.3 to 12.4)3514.47 (4.17 to 4.81)12.7 (11.8 to 13.2)
Platelets, ×109/L
 10 days to <1 year281262 (239 to 271)598 (559 to 621)228237 (221 to 253)573 (557 to 589)
 >1 to <3 years816200 (191 to 209)513 (496 to 527)706213 (190 to 224)530 (518 to 545)
 >3 to <6 years988195 (184 to 204)446 (441 to 465)843208 (201 to 214)439 (432 to 443)
 ≥6 to 10 years421202 (190 to 210)421 (414 to 435)347197 (184 to 202)399 (389 to 442)