Table 4.

Population attributable risk for a fractional fall in hematocrit of > 25% before and after malaria treatment

Risk factor	Frequency (%)	AOR (95% confidence interval)*	PAR† (%)	P value
Before treatment‡
Aged ≤ 5 years	17	2.6 (2.2–3.1)	21.4	<0.001
Recrudescent infections	27	1.9 (1.5–2.4)	19.5	0.005
Palpable spleen	23	2.7 (2.3–3.2)	28.1	<0.001
Palpable liver	16	1.8 (1.4–2.3)	11.3	0.01
After treatment§
Aged ≤ 5 years	17	2.2 (1.7–2.7)	16.9	<0.001
High parasitemia (μ 100,000 parasites/μL)	10	2.4 (1.9–2.9)	12.3	<0.001
Prolonged preadmission history	65	2.9 (2.4–3.5)	55.3	<0.001
Parasitemia not cleared in 24 hr	64	2.7 (2.1–3.2)	52.1	<0.001

^*AOR = adjusted odds ratio. AORs and 95% confidence intervals of the risk associated with the presence of the factor when compared with its absence after adjustment for the other factors in the table. AORs were calculated by logistic regression analysis.

^†PAR = population attributable risk. PAR is for a fractional drop in hematocrit from normal values of > 25%. The overall PAR was calculated as 1 minus the product of 1 minus each individual PAR.

^‡Overall PAR before treatment is 59.6.

^§Overall PAR after treatment is 84.4.