School-Based Health Centers, Access to Care, and Income-Based Disparities.

Importance: School-based health centers (SBHCs) are primary care clinics colocated at schools. SBHCs have the potential to improve health care access and reduce disparities, but there is limited rigorous evidence on their effectiveness at the national level. Objective: To determine whether county-level adoption of SBHCs was associated with access, utilization, and health among children from low-income families and to measure reductions in income-based disparities. Design, Setting, and Participants: This survey study used a difference-in-differences design and data from a nationally representative sample of children in the US merged with SBHC indicators from the National Census of School-Based Health Centers. The main sample included children aged 5 to 17 years with family incomes that were less than 200% of the federal poverty level observed in the National Health Interview Survey, collected between 1997 to 2018. The sample was restricted to children living in a county that adopted a center between 2003 and 2013 or that did not have a center at any time during the study period. Analyses of income-based disparities included children from higher income families (ie, 200% or higher than the federal poverty level). Data were analyzed between January 2020 and July 2023. Exposure: County-by-year SBHC adoption. Main Outcomes and Measures: Outcomes included access (usual source of care, insurance status, barriers), ambulatory care use (general physician, eye doctor, dental, mental health visits), and health (general health status, missed school days due to illness). P values were adjusted for multiple comparisons using the sharpened q value method. Results: This study included 12 624 unweighted children from low-income families and 24 631 unweighted children from higher income families. The weighted percentage of children in low-income families who resided in counties with SBHC adoption included 50.0% aged 5 to 10 years. The weighted percentages of the race and ethnicity of these children included 36.7% Hispanic children, 25.2% non-Hispanic Black children, and 30.6% non-Hispanic White children. The weighted percentages of children in the counties that never adopted SBHCs included 50.1% aged 5 to 10 years. The weighted percentages of the race and ethnicity of these children included 20.7% Hispanic children, 22.4% non-Hispanic Black children, and 52.9% non-Hispanic White children. SBHC adoption was associated with a 6.4 percentage point increase in dental visits (95% CI, 3.2-9.6 percentage points; P < .001), an 8.0 percentage point increase in having a usual source of care (95% CI, 4.5-11.5 percentage points; P < .001), and a 5.2 percentage point increase in insurance (95% CI, 1.2-9.2 percentage points; P = .03). No other statistically significant associations were found with other outcomes. SBHCs were associated with relative reductions in income-based disparities to dental visits by 76% (4.9 percentage points; 95% CI, 2.0-7.7 percentage points), to insured status by 63% (3.5 percentage points; 95% CI, 1.3-5.7 percentage points), and to having a usual source of care by 98% (7.2 percentage points; 95% CI, 5.4-9.1 percentage points). Conclusions and Relevance: In this survey study with difference-in-differences analysis of SBHC adoption, SBHCs were associated with access to care and reduced income-based disparities. These findings support additional SBHC expansion.