Research Letter
November 20, 2023
School Performance in Third Grade After a Full-Day vs Part-Day Preschool Program
Arthur J. Reynolds, Nicole E. Smerillo, Suh-Ruu Ou, et al
JAMA. Published online November 20, 2023. doi:10.1001/jama.2023.20010
Preschool improves educational outcomes and well-being, especially for economically disadvantaged children.1 Most evidence is from part-day programs. Whether full-day preschool (FDP) promotes sustained learning gains has rarely been tested, despite its expansion in recent years.2 The Child-Parent Centers (CPC) program began in 1967 and was designed to promote children’s school success. In a previous article, FDP compared with part-day preschool (PDP) in CPCs in Chicago, Illinois, was associated with greater readiness skills in 4 of 6 domains at the end of the year.3
To assess whether associated gains were sustained, we conducted a follow-up through third grade, analyzing achievement scores and need for remediation.
The Midwest CPC, an expansion of the CPCs to economically diverse communities in 4 Illinois and Minnesota districts, provides enriched services in 6 core components: effective learning experiences, family engagement, aligned curriculum, professional development, continuity and stability, and collaborative leadership (eTable and eAppendix in Supplement 1).4
This study includes the Chicago cohort of the Midwest CPC, which has tracked a nonrandomized group of 2630 economically disadvantaged children since 2012-2013.4 As in a previous study,3 we focused on 3- and 4-year-old children in 11 of the 16 Chicago CPCs offering FDP and PDP. Mean class sizes were 18.1 for FDPs and 16.0 for PDPs, with FDP lasting 7 hours per day vs 3 hours per day for PDPs.3 The study was approved by review boards of the University of Minnesota and districts. Informed consent from parents and guardians was written and oral.
Third-grade follow-up was conducted through 2017-2018, and 4 outcomes from school records included (1) English/language arts (ELA) scores and proficiency and (2) math scores and proficiency on the state Partnership for Assessment of Readiness for College and Careers test in third grade (range, 650-850; proficiency defined as level ≥4 [5 levels]),5 (3) grade retention through third grade, and (4) special education placement through third grade.
Data were analyzed using generalized estimating equations (SPSS version 29; IBM) with school-level clustering, adjusted for 13 covariates (eg, baseline skills, race and ethnicity; eAppendix in Supplement 1) and attrition, via inverse propensity score weighting. Statistical significance was defined as P < .05 (2-tailed). Standardized mean differences (SMDs) were reported for outcomes (dichotomies converted via probit transformation) to allow comparison across measures and studies. Differences of greater than 0.2 were defined as practically significant.3,4 Sensitivity analyses were conducted for children at less than 130% of the poverty level. Interactions with implementation quality, measured by center ratings of collaborative leadership (high [≥4] vs low [<4]; 5-point scale) were tested for all outcomes.
At follow-up, 88.3% (361 of 409) and 89.5% (513 of 573) of the FDP and PDP groups, respectively, were enrolled in the district with available outcomes. Demographic characteristics in the cohort (mean age, 8.8 years; Black, 91.9%; Hispanic, 7.3%) were similar to the original sample.3 FDP was associated with higher ELA scores compared with PDP (725.0 vs 716.1; difference, 8.9 [95% CI, 1.6 to 16.2]; P = .02; SMD, 0.24) and higher ELA proficiency (38.3% vs 26.8%; difference, 11.5% [95% CI, 0.9% to 22.2%]; P = .03; SMD, 0.32; Table). FDP, compared with PDP, was associated with higher math scores (725.5 vs 719.3; difference, 6.2 [95% CI, 0.2 to 12.2]; P = .04; SMD, 0.20). Math proficiency reached practical but not statistical significance (25% vs 17.4%; difference, 7.6% [95% CI, −0.1% to 15.4%]; P = .055; SMD, 0.27).
FDP was associated with lower percentages of grade retention vs PDP (3.0% vs 9.1%; difference, −6.1% [95% CI, −11.1% to −1.1%]; P = .02; SMD = −0.54), but not special education placement. Group differences among low-income children were similar to the overall sample (Table). The implementation quality by FDP status interaction P value was only significant for ELA proficiency (P = .044). FDP vs PDP was more strongly associated with ELA proficiency in centers with high implementation quality (39.6% vs 20.3%; difference, 19.3% [95% CI, 14.5% to 24.1%]; SMD, 0.59) vs low implementation quality (27.2% vs 21.0%; difference, 6.2% [95% CI, −0.4% to −12.8%]; SMD, 0.19).
This study found that an evidence-based preschool program implemented full day vs part day was associated with sustained achievement gains and reduced grade retention. FDP may be preferable to PDP, especially among children in economically disadvantaged communities.1,6 Implementation quality appears to bolster gains.3 The individual components of CPCs warrant broader investigation in a variety of contexts. Study limitations include unknown generalizability beyond Chicago or to other programs.
