TABLE 2.

Multilevel repeated-measure linear regression models of the effects of reinfection with Schistosoma japonicum on mean hematological and iron status measures in 580 7- to 30-year-old patients^a

Variable	Hemoglobin			Serum ferritinb			Serum transferrin receptorb
	β	SE	P value	β	SE	P value	β	SE	P value
Interceptc	12.187	0.071	<0.0001	3.266	0.05	<0.0001	8.706	0.026	<0.0001
T3	0	0		0	0		0	0
T6	0.403	0.053	<0.0001	0.240	0.042	<0.0001	−0.126	0.018	<0.0001
T9	0.429	0.085	<0.0001	0.101	0.042	0.015	−0.075	0.024	0.002
T12	0.664	0.071	<0.0001	0.311	0.048	<0.0001	0.213	0.030	<0.0001
T15	0.796	0.093	<0.0001	0.314	0.059	<0.0001	0.169	0.035	<0.0001
T18	0.639	0.102	<0.0001	0.205	0.067	0.002	0.144	0.042	<0.001
Aged	0.145	0.010	<0.0001	0.058	0.005	<0.0001	−0.022	0.003	<0.0001
Sexd	−0.487	0.105	<0.0001	−0.196	0.066	0.003	0.066	0.044	0.13
Socioeconomic statusd	0.279	0.065	<0.0001	0.137	0.037	<0.001	−0.086	0.023	<0.001
Hookworm egg counte	0.003	0.007	0.66	−0.008	0.005	0.14	0.001	0.003	0.62
Baseline S. japonicum egg countd	−0.086	0.039	0.027	−0.029	0.025	0.25	0.031	0.015	0.037
Durationf	−0.038	0.019	0.042	0.021	0.007	0.002	0.015	0.008	0.066
S. japonicum egg countg	−0.072	0.041	0.081	0.037	0.011	<0.001	0.003	0.006	0.65
Duration × S. japonicum egg counth	0.015	0.009	0.11	−0.003	0.001	0.024	−0.002	0.002	0.25
S. japonicum egg count × S. japonicum egg counti	0.016	0.008	0.052
Duration × S. japonicum egg count × S. japonicum egg counth	−0.003	0.001	0.009
Duration × durationi							−0.001	0.001	0.017
Duration × duration × S. japonicum egg counth							0.0003	0.0001	0.028

^aβ-Estimates (excluding the intercept) represent mean changes of the outcome per unit change of the exposure. β-Estimates and SE were adjusted for within-person correlation, for clustering within households, and for confounding by covariates. T3 to T18 represent the trimonthly posttreatment follow-ups, and the 3-month follow-up is the reference category.

^bSerum ferritin and serum transferrin receptor were ln transformed.

^cThe intercept represents the outcome mean at the 3-month follow-up for an average individual (i.e., an individual with a mean value for each of the covariates). The P value indicates whether the intercept is significantly different from zero.

^dThe confounders age, sex, SES, and baseline ln-transformed S. japonicum egg count were centered on their baseline means.

^eln-transformed hookworm egg counts were centered on the mean for all posttreatment observations.

^fDefined as the time since reinfection with S. japonicum.

^gln-transformed S. japonicum egg count.

^hInteraction term.

ⁱQuadratic function (indicates a nonlinear relationship between the exposure and the outcome).