Participating in high-quality pre-K reduces a child’s likelihood of being diagnosed with certain learning disabilities by 3rd grade by as much as 32 percent, according to new research published in the American Educational Research Association’s journal, Educational Evaluation and Policy Analysis.

Attendance in prekindergarten did not, however, have any bearing on special education placement for children with physical disabilities, speech or language impairments or behavioral-emotional disabilities. Researchers Clara G. Muschkin, Helen F. Ladd and Kenneth A. Dodge of Duke University examined the effects of two early childhood programs in North Carolina on the likelihood that children would be placed in special education classes by 3rd grade. One program provided child health and family services to high-need children from birth to age 5, and the other was a preschool program for at-risk 4-year-olds. The study tracked 871,000 children born between 1988 and 2000.

Using information contained in each child’s birth record (such as low birth weight), the researchers calculated each child’s odds of needing special education services in 3rd grade in the absence of early intervention. The odds were then compared with each child’s actual 3rd-grade placement in special education or a general education classroom.

Researchers found that participation in the state’s prekindergarten program for 4-year-olds (at the 2009 funding of $1,110 per child) reduced the likelihood of 3rd-grade special education placements by 32 percent, while access to the child health and family services program reduced the odds by 10 percent. Researchers saw a 39 percent reduction in special education placements for children who participated in both early childhood programs. The benefit was greatest for children from high-poverty backgrounds who participated in both programs.

Muschkin said the findings should encourage policymakers to invest in early childhood programs to avoid more spending on special education down the road.