Children who have the opportunity to attend full-day preschool programs, versus part-day programs, tend to score higher on school readiness measures such as language, math, socio-emotional development and physical health, according to a recent study. So, why is this finding important to public health? Because education has literally been described as an “elixir” for lifelong health and wellbeing.

When it comes to the upstream factors that can put people on a lifelong trajectory toward longer life expectancy, greater health and less chance of disability and disease, educational achievement is one of the key determinants. In fact, public health researchers have tapped education as one of the strongest predictors of health later in life. And a study published this week in the Journal of the American Medical Association (JAMA) finds that access to high-quality early childhood programs that promote school readiness for young kids ages 3 to 4 years old can put them on the right path toward education achievement and, hopefully, better health. Researchers Arthur Reynolds, Brandt Richardson, Momoko Hayakawa, Erin Lease, Mallory Warner-Richter, Michelle Englund, Suh-Ruu Ou and Molly Sullivan write:

In addition to increasing the amount of learning time, full-day preschool can increase continuity in learning as children avoid multiple education placements during the day; reduce family stress by increasing time for parents to pursue employment and education; and promote long-term effects on well-being. Although evidence from prior studies is meager, implementation of full-day preschool within a high-quality, evidenced-based model may be particularly cost-effective, especially for children exposed to early adversity.

To conduct the study, researchers examined a group of predominantly low-income, ethnic minority children enrolled in full- and part-day preschool programs among 11 Chicago schools during the 2012–2013 school year. At the end of the preschool year, researchers evaluated a number of school readiness skills and related measures. They found that compared to children participating in part-day preschool, children enrolled in full-day preschool had higher scores on socio-emotional development measures, language, math and physical health. Scores between the two groups were not significantly different for cognitive development and literacy.

In addition, children in full-day preschool had higher rates of attendance and lower rates of chronic absences, which is defined as missing 10 percent or more days of school. No significant difference was detected between the two groups in regard to parental school involvement.

Overall, full-day preschoolers had a significantly higher rate of mastery on the “total readiness metric,” with nearly 81 percent of full-day preschoolers at or above the national average on four or more readiness measures. In comparison, only about 59 percent of part-day preschoolers achieved similarly high readiness scores. In other words, more time spent in preschool was associated with 17 percent to 38 percent increases in young children meeting national norms in language, math, socio-emotional development and literacy.

In an editorial accompanying the study, author Lawrence Schweinhart, president of the HighScope Educational Research Foundation in Michigan, wrote that while the study did find statistically significant benefits to full-day preschool, it might not be enough to persuade decision-makers that funding more opportunities for full-time preschool is justified. Still, he wrote, it’s a discussion worth having.

“This must be debated and discussed by parents, educators and policy-makers and the longer-term effects and economic returns studied,” Schweinhart writes. “But the findings are large enough to assure parents and the rest of the public that the positive benefits found for high-quality part-day preschool were found in high-quality full-day preschool to an even greater extent.”

The JAMA study noted that publicly funded preschool such as Head Start and state prekindergarten programs serve about 42 percent of U.S. 4-year-olds, though most only offer part-day programs. Also, only 15 percent of 3-year-olds are enrolled.

To learn more about access to state-funded preschool in the U.S., visit this New York Times interactive map. To download a copy of the JAMA study, click here.

Kim Krisberg is a freelance public health writer living in Austin, Texas, and has been writing about public health for more than a decade.