Table 6. Effect of STH and hookworm infections on hemoglobin levels in podoconiosis patients using multivariate regression.

Variable	Beta β**	95%CI	P value *
Podoconiosis * ‘any STH’ †	−1.07	−1.62 to −0.52	0.01
Podoconiosis* ‘hookworm’ ††	−1.02	−1.62 to −0.41	0.01
Podoconiosis * ‘non-hookworm STH’ * ‘hookworm’ †††	−1.54	−2.89 to −0.19	0.02

^*Interaction term.

^**Adjusted for age, sex, occupation and educational status.

The reference group for different categories of geohelminth infections was defined to include the following:

^†For any STH infections: Podoconiosis patients uninfected by any species of geohelminth.

^††For hookworm infection: Podoconiosis patients uninfected by any species of geohelminth, and patients infected with non hookworm geohelminths.

^†††For non-hookworm STH and hookworm: Podoconiosis patients uninfected by any species of geohelminth, and patients infected with only one species.