Comparison of Full Blood Count Parameters Using Capillary and Venous Samples in Patients Presenting to the Emergency Department

Table 3

Difference (𝑑) in blood parameters of capillary samples from their corresponding laboratory values (C-V) for low, normal, and high ranges of their laboratory readings.

Blood parameter	Statistics for 𝑑	Laboratory range for blood parameter
White blood count (×10^9/L)		Low (<4)	Normal (4–10)	High (>10)
		𝑛=6	𝑛=230	𝑛=78
	Mean	−0.20	−0.08	−0.03
	SD	0.35	0.68	1.20
	Range	−0.60, 0.20	−1.50, 2.72	−2.40, 3.60
	Limits of agreement^§	−0.89, 0.49	−1.41, 1.25	−2.38, 2.32
Platelet (×10^9/L)		Low (<140)	Normal (140–440)	High (>440)
		𝑛=15	𝑛=286	𝑛=13
	Mean	7.3	−2.2	−45.8
	SD	9.4	31.3	31.4
	Range	−11, 30	−84, 76	−93, 20
	Limits of agreement^§	−11.1, 25.7	−63.6, 59.2	−107.3, 15.7
Haemoglobin (g/dL)		Low (<13)	Normal (13–17)	High (>17)
		𝑛=127	𝑛=184	𝑛=3
	Mean	−0.5	−0.5	0.1
	SD	0.4	0.5	0.7
	Range	−1.9, 0.9	−1.9, 0.9	−0.6, 0.7
	Limits of agreement^§	−1.3, 0.3	−1.5, 0.5	−1.3, 1.5

^§ Limits of agreement were calculated as (Mean − 1.96 SD, Mean + 1.96 SD). Most of the differences (95% of them) were expected to lie within these limits.