Outcomes of a universal shared reading intervention by 2 years of age: the Let's Read trial.

Abstract

Early shared reading and literacy promotion benefits have stimulated international interest in the development of early-years literacy-promotion programs despite limited evidence of effectiveness at a broader population level. To determine whether a population-based primary care literacy promotion intervention during the first 2 years of life improves early markers of subsequent literacy by 2 years of age. This cluster randomized controlled trial took place in 5 relatively disadvantaged areas in Melbourne, Australia. Infants attending their maternal and child health centers were recruited at age 1-2 months. The intervention (4-8, 12, and 18 months) comprised maternal and child health nurses modelling shared reading activities to parents, supported by parent information and free books. Outcomes (at 2 years) included expressive vocabulary (MacArthur Bates Communicative Development Inventory), communication (Communication and Symbolic Behavior Scales), and home literacy environment (StimQ-Toddler). We analyzed the outcomes using random-effects (linear regression) models allowing for clustering. A total of 552 families (87.6%; 324 intervention and 228 control families) of 630 recruited families (66.5% response) were retained to outcome. A total of 97.3% of intervention parents received some (93.7% to all) of the intervention. At 2 years, the trial arms had similar vocabulary (adjusted mean difference: -2.0 [95% confidence interval: -6.2 to 2.2]; P = .36), communication (adjusted mean difference: 0.2 [95% confidence interval: -2.3 to 2.7]; P = .87), and home literacy (adjusted mean difference: -0.4 [95% confidence interval: -1.0 to 0.2]; P = .21). This universal literacy-promotion program was not beneficial in relatively disadvantaged communities by the age of 2 years and may be ineffective. Alternative interpretations may relate to program intensity, reach and/or sleeper effects. Definitive outcomes at 4 years are awaited.