Table 2.

Comparison between parasite densities (parasites/µl) calculated using actual WBC count and those estimated using assumed WBC counts

WBC count/µl	Median	Range (min~max)	IQR	Mean ± SD	P*
Actual count	1,903	30~44,493	752~3,579	3,196±4,881	--
8000	2,570	40~48,100	1,055~5,320	4,362±5,801	<0.0001
7000	2,249	35~42,088	923~4,655	3,817±5,076	<0.0001
6000	1,928	30~36,075	791~3,990	3,272±4,351	0.2315
5500	1,767	28~33,069	725~3,658	2,999±3,988	0.0814
5000	1,607	25~30,063	660~3,325	2,727±3,626	<0.0001
4000	1,285	20~24,050	528~2,660	2,181±2,901	<0.0001

^*P: Wilcoxon matched-pairs signed rank test between the median parasite density derived from an assumed WBC count (4,000–8,000) and that from an automated WBC counter. IQR, interquartile range; SD, standard deviation.