Children who attend a full-day preschool program are better prepared for school than those who attend a part-time program, according to a recent study.

Researchers from the University of Minnesota found that children who attended a full-day preschool program had higher scores on measures of school readiness skills, increased attendance, and reduced chronic absences compared to children who attended part-day preschool.

Participation in high-quality early childhood programs at ages 3 and 4 years is associated with greater school readiness and achievement, higher rates of educational attainment and socioeconomic status, and lower rates of crime.

 Although publicly funded preschool such as Head Start and state prekindergarten serve an estimated 42 percent of U.S. 4-year­-olds, most provide only part-day services, and only 15 percent of 3-year-olds enroll. These rates plus differences in quality may account for only about half of entering kindergartners having mastered skills needed for school success. One approach for enhancing effectiveness is increasing from a part-day to a full-day schedule; whether this improves outcomes is unknown, according to background information in the article.

For the study, researchers colleagues investigated whether full-day preschool was associated with higher levels of school readiness, attendance, and parent involvement compared with part-day participation. The study consisted of an end-of-preschool follow-up of a group of predominantly low-income, ethnic children enrolled in the Child-Parent Centers (CPC) for the full day (7 hours; n = 409) or part day (3 hours on average; n = 573) in the 2012-2013 school year in 11 schools in Chicago.

At the end of preschool, the researchers evaluated school readiness skills (in several domains) of the children, attendance and chronic absences, and parental involvement. They found that full-day preschool participants had higher scores than part-day peers on measures of socio-emotional development (58.6 vs 54.5), language (39.9 vs 37.3), math (40.0 vs 36.4), and physical health (35.5 vs 33.6). Scores for literacy (64.5 vs 58.6) and cognitive development (59.7 vs 57.7) were not significantly different.

Full-day preschool graduates also had higher rates of attendance (85.9 percent vs 80.4 percent) and lower rates of chronic absences (10 percent or greater days missed; 53.0 percent vs 71.6 percent; 20 percent or greater days missed; 21.2 percent vs 38.8 percent), but no differences in parental involvement.

"Full-day preschool appears to be a promising strategy for school readiness. The size and breadth of associations go beyond previous studies. The positive association of full-day preschool also suggests that increasing access to early childhood programs should consider the optimal dosage of services. In addition to increased educational enrichment, full-day preschool benefits parents by providing children with a continually enriched environment throughout the day, thereby freeing parental time to pursue career and educational opportunities. By offering another service option, full-day preschool also can increase access for families who may not otherwise enroll," the authors write.

The findings are detailed in the November 26 issue of JAMA.