Head Start Impact on Long-Term Cognitive Outcomes for Children with Disabilities

Purpose:  In the US, 2.8 million school-aged children (5.2 percent of the 53.9 million school-aged children) are reported to have a disability. Children with disabilities have significant risk factors for poor outcomes at young ages, which also affect social, emotional, and learning difficulties at later ages.  Evidence indicates that early childhood development programs like Head Start have a positive effect on increasing readiness to learn, preventing the delay of cognitive development, and social-emotional improvements. Despite well-known short-term findings, little research evidence is available for Head Start’s impact on long-term outcomes for children with disability. This study examined whether Head Start has any long-term impacts on cognitive outcomes for children with disabilities.

Methods: The present study used the Head Start Impact Study collected during 2002-2008. Among 570 children with disabilities, 278 children who entered Head Start (HS) at age 4 and enrolled for 1 year were selected for this study. Cognitive outcomes were measured by the Woodcock-Johnson III Test of Achievement, Applied Problem Solving Skills and Word Identification Skills and Peabody Picture Vocabulary Test (PPVT) scores, measured from ages 4 (Fall 2002) to age 9 (Spring 2008).  A linear mixed model analysis determined whether HS enrollment has any impacts on children’s cognitive outcomes. The fixed effects were Head Start enrollment over time in addition to all baseline variables, treating child ID as random effects, and treating “time” as repeated measures of random errors and adopting Bonferroni method for multiple comparisons.

Results: Compared to non-HS children, children with disability who enrolled in HS had higher applied problem solving scores in 2003 (76.2 vs 81.2^*) and 2005 (88.9 vs 92.3^*), higher PPVT scores in 2003 (85.0 vs 87.3^*) and 2005 (82.5 vs 85.7^**), and higher word recognition skills in 2004 (89.9 vs 93.2⁺).  However, no difference was found between HS and non-HS children for cognitive outcomes measured in 2008 (at age 9).  Compared with year 2002 and 2003, variance coefficients scores in years 2004, 2005, and 2008 have smaller variances, which illustrates that as children became older, individual differences in cognitive outcomes were decreased.  The finding also suggests that high cognitive scores at an earlier age were associated with higher scores at later age. Children who had an IEP, those speaking Non-English at home, and those who had lower pre-academic skills prior to HS had significantly lower cognitive outcomes measured at ages 4 to 9.

Implications:  Although HS had significant short-term positive impacts on cognitive outcomes for children with disabilities, the positive impacts seem to weaken as children become older after they exit the HS program. This may be due to the transition into a less enriched and supportive environment for elementary school. Adverse impact of IEP on cognitive outcomes suggests for a future study on why the intended benefits of IED did not materialize for Head Start eligible children with disability. Other factors such as non-English speaking at home, lower pre-academic skills at an earlier age should also be considered in assessing long-terms cognitive development for children with disabilities living in poverty.