Objective: To determine whether maternal literacy level accounts for associations between educational level and the cognitive home environment in low-income families.
Design: Analysis of 369 mother-infant dyads participating in a long-term study related to early child development.
Setting: Urban public hospital.
Participants: Low-income mothers of 6-month-old infants.
Main exposure: Maternal literacy level was assessed using the Woodcock-Johnson III/Bateria III Woodcock-Munoz Tests of Achievement, Letter-Word Identification Test. Maternal educational level was assessed by determining the last grade that had been completed by the mother.
Main outcome measure: The cognitive home environment (provision of learning materials, verbal responsivity, teaching, and shared reading) was assessed using StimQ, an office-based interview measure.
Results: In unadjusted analyses, a maternal literacy level of ninth grade or higher was associated with increases in scores for the overall StimQ and each of 4 subscales, whereas a maternal educational level of ninth grade or higher was associated with increases in scores for the overall StimQ and 3 of 4 subscales. In simultaneous multiple linear regression models including both literacy and educational levels, literacy continued to be associated with scores for the overall StimQ (adjusted mean difference, 3.7; 95% confidence interval, 1.7-5.7) and all subscales except teaching, whereas maternal educational level was no longer significantly associated with scores for the StimQ (1.8; 0.5-4.0) or any of its subscales.
Conclusions: Literacy level may be a more specific indicator of risk than educational level in low-income families. Studies of low-income families should include direct measures of literacy. Pediatricians should develop strategies to identify mothers with low literacy levels and promote parenting behaviors to foster cognitive development in these at-risk families.