The launch of Pre-K for All led to improved health outcomes for low-income children. That’s according to researchers at New York University who analyzed Medicaid data for New York City children who were eligible to enroll in free pre-K versus those who just missed the cutoff because of their age.

In a report released this month by the National Bureau of Economic Research, using data from 2013 through 2016, researchers found that the children eligible for pre-K were more likely than their peers to be diagnosed with asthma or vision problems after the rollout of Pre-K for All. They were also more likely to have received immunizations or be screened for infectious diseases, both of which are requirements for enrolling in the city’s program.

Proper medical screening could have implications beyond physical well-being, the researchers suggest. Diagnosing and treating chronic health problems earlier could help students “cope with challenges, feel less frustrated or overwhelmed in the classroom, and communicate with peers and educators more effectively,” the study found.

One of the most significant findings, according to authors Kai Hong, Kacie Dragan and Sherry Glied, was that children were also more likely to receive treatment for vision and hearing problems. Vision impairments, which are prevalent among poor children in urban environments, have been correlated with poor performance in school, the study notes. Meanwhile, school-based support for children with hearing problems can help them develop on par with their healthy peers.

The findings could help explain why other studies have shown that pre-K can lead to long-term advantages such as increased chances of finding a job and decreased chances of teen pregnancy, according to the study.

“If a young student’s health conditions are well-managed — particularly sensory problems that could impede learning — then the child may have the chance to develop successful long-term learning strategies or problem-solving capacities in comparison to a child who remains burdened by undetected or poorly-managed conditions early in their education,” the researchers note.

Other studies that have looked into the health impacts of pre-K have produced mixed results, said Glied, a coauthor of the study and the dean of the Robert F. Wagner Graduate School of Public Service at NYU.

New York City’s program offered researchers with the opportunity to conduct a “more rigorous” analysis, given its scale and quality, she told Chalkbeat. About 70,000 students are now enrolled in Pre-K for All, the program Mayor Bill de Blasio began ramping up in 2014.

“This was a good opportunity,” Glied said, “to nail down the effects of universal pre-K.”