Table 8.

Multivariate regression determining zinc level in serum in pre-school-age children (PSAC) and non-pregnant non-lactating women (NPNLW)

	PSAC*			NPNLW†
Covariates	Coefficient	P	β	Coefficient	P	β
Hb	0·001	0·98	0·0009	0·18	0·005	0·10
Household expenses	0·18	0·43	0·06	0·42	0·007	0·13
Age	0·014	0·22	0·08	−0·012	−0·07	−0·07
Occupation of household head
Non-agricultural (reference agricultural)	0·29	0·21	0·085	0·27	0·054	0·07
Women's education
Secondary (reference below secondary)	0·17	0·59	0·033	−0·003	0·98	−0·0005
Intake of animal-source Zn	0·00003	0·07	0·13	0·00002	0·02	0·096
Intake of plant-source Zn	−0·000025	0·038	−0·13	−0·00002	0·001	−0·13
Asset score	0·08	0·58	0·05	0·23	0·03	0·11
Area of residence
Urban (reference slum)	1·37	0·03	0·33	0·18	0·64	0·04
HFIAS score	0·04	0·12	0·11	0·02	0·10	0·066

HFIAS, Household Food Insecurity Access Scale.

^*Interaction terms – (occupation of household head × intake of animal-source Zn), (occupation of household head × intake of plant-source Zn), (asset score × intake of animal-source Zn), (household expenses × intake of animal-source Zn), (stratum × intake of animal-source Zn), and (household expenses × educational status of women) were separately assessed through initial regression equations, along with component predictors. However, none of the interaction terms reached statistical significance level at P < 0·05 except for (household expenses × occupation of household head) (P = 0·049), which was considered in the final multivariate model; however, it had a non-significant interaction (P = 0·44) and as such was removed from the model.

^†Interaction terms – all the interaction terms assessed for the PSAC were tested in NPNLW. In the initial regression analyses none had significant interaction except for the household expenses × intake of animal-source Zn (P = 0·03). It was considered in the final multivariate model where it is reported to have significant interaction (P = 0·01).