A longitudinal study of WIC participation on household food insecurity.

We examined the association between women's/children's duration of WIC participation and household food security status. For mothers (n = 21,863) and their children (n = 57,377) participating in WIC (2001-2006), longitudinal measures of household food security status were collected using a subscale of the USDA Food Security Module. Using logistic regression, household food security status at the last WIC visit was associated with measures of WIC duration (number of trimesters on WIC for pregnant women, and number of WIC visits for children). Among women with prenatal household food insecurity with hunger, odds of any post-partum household food insecurity was reduced with first (AOR = 0.67, 95% CI = 0.48-0.94) or second trimester of entry (AOR= 0.64, 95% CI = 0.45-0.90) versus third. Among children with initial household food insecurity without hunger, an additional WIC visit reduced the odds of any household food insecurity (AOR = 0.92, 95% CI = 0.90-0.94) and of household food insecurity with hunger (AOR = 0.94, 95% CI = 0.89-0.98) at the last visit. Among those with initial household food insecurity with hunger, an additional WIC visit reduced the odds of any household food insecurity (AOR = 0.96, 95% CI = 0.92-0.99) and of household food insecurity with hunger (AOR = 0.88, 95% CI = 0.83-0.94) at the last visit. Earlier and longer WIC participation may improve household food security status, particularly of vulnerable groups.