Highlights
- A blended delivery model—alternating home visits with telephone calls—successfully improved children’s overall developmental quotient and fine motor skills.
- The intervention, delivered through existing primary health care infrastructure, significantly enhanced parenting behaviors, including responsivity and involvement.
- Results suggest that hybrid delivery is a feasible and effective strategy for scaling early childhood development (ECD) programs in low-and-middle-income countries (LMICs).
- The study utilized community health workers (CHWs), demonstrating the potential for task-shifting in resource-constrained environments.
Introduction: The Imperative for Scalable Child Development Interventions
Early childhood development (ECD) is a critical determinant of lifelong health, educational attainment, and economic productivity. Despite the established benefits of parenting programs that promote play and responsive caregiving, a significant gap remains: how to scale these interventions within government services without compromising efficacy or incurring prohibitive costs. Approximately 250 million children under five in low- and middle-income countries are at risk of not reaching their developmental potential due to poverty and lack of stimulation.
Traditionally, high-impact programs like the Jamaican ‘Reach Up’ model have relied on intensive home visiting. However, the logistical and financial burdens of frequent home visits often hinder national scaling efforts. The study by Chang et al., published in JAMA Network Open, addresses this challenge by evaluating a ‘blended’ delivery model that integrates remote support with traditional in-person visits within the Jamaican primary health care system.
Study Design and Methodology
This single-blind randomized clinical trial was conducted in primary health care centers across Jamaica. Enrollment began in July 2022, targeting families with children aged 3 to 28 months. A total of 627 children were enrolled and randomly assigned to either the intervention group (n = 311) or a waiting list control group (n = 316).
The Intervention Protocol
The intervention lasted eight months and was characterized by fortnightly contacts between community health workers (CHWs) and families. The innovative ‘blended’ aspect involved alternating between face-to-face home visits and telephone calls. This structure aimed to maintain the personal connection and hands-on coaching of home visits while utilizing the efficiency and lower cost of remote communication.
The curriculum, based on the Reach Up program, focused on strengthening parents’ skills in helping their children learn through play and language. CHWs provided age-appropriate activities and coached parents on responsive interactions, using low-cost or homemade materials to ensure sustainability within the home environment.
Outcome Measures
The primary outcome was child development, assessed using the Griffiths Mental Development Scales (GMDS), which provide a developmental quotient (DQ) across various domains, including locomotor, personal-social, language, and fine motor skills. Secondary outcomes included parenting behaviors, measured by the Home Observation for Measurement of the Environment (HOME) inventory. This tool evaluates the quality and quantity of stimulation and support available to a child in the home, focusing on subscales such as parental responsivity, involvement, and the provision of learning materials.
Key Findings: Developmental and Behavioral Impact
The results of the trial provide robust evidence for the efficacy of the blended delivery model. At the follow-up assessment (mean age 27 months), the intervention group showed significant improvements across several key metrics compared to the control group.
Child Developmental Outcomes
Intention-to-treat multivariate regression analyses, utilizing inverse probability weights to account for attrition, revealed a significant benefit for the children’s overall developmental quotient. The effect size (ES) was 0.17 standard deviations (SD) (95% CI, 0.01-0.33 SD). Notably, fine motor ability scores showed a distinct improvement with an ES of 0.19 SD (95% CI, 0.03-0.36 SD). While other subscales showed positive trends, the overall DQ and fine motor skills reached statistical significance, suggesting that the intervention successfully stimulated cognitive and physical development.
Parenting Behavior Outcomes
The intervention had an even more pronounced effect on parenting behaviors. The total HOME score showed a significant benefit with an ES of 0.25 SD (95% CI, 0.08-0.41 SD). Specifically, parents in the intervention group demonstrated higher levels of responsivity and involvement in their children’s activities. These changes are crucial, as improved parenting behaviors are considered the primary mechanism through which early childhood interventions achieve long-term developmental gains.
Clinical and Policy Implications
The significance of this trial lies in its implementation strategy. By utilizing community health workers within the existing primary care framework, the study demonstrates that ECD interventions can be integrated into routine government services.
Scalability and Cost-Effectiveness
The blended model addresses two major barriers to scaling: workforce capacity and transportation costs. Alternating home visits with telephone calls reduces the travel time required for CHWs, allowing them to manage larger caseloads or cover wider geographic areas. For families, the remote component reduces the burden of scheduling and provides a consistent touchpoint that reinforces the lessons learned during in-person visits.
Mechanistic Insights
The improvement in the HOME scores suggests that the intervention successfully altered the home environment. By coaching parents to use everyday moments as learning opportunities, the program creates a sustainable impact that continues beyond the 8-month intervention period. The focus on fine motor skills and language activities likely provided the specific stimulation needed during this sensitive period of neurodevelopment.
Expert Commentary: Strengths and Considerations
This study is a landmark in implementation science for early childhood development. Its strengths include the randomized design, the use of validated developmental scales, and the pragmatic setting of government health centers. However, there are considerations for generalizability. The follow-up rate was 78.3%, and while the researchers used inverse probability weighting to mitigate bias, the attrition highlights the challenges of long-term engagement in community-based trials.
Furthermore, the success of the remote component depends on mobile phone penetration and network reliability. While Jamaica has high mobile usage, other regions may face digital divides that could limit the effectiveness of telephone-based coaching. Future research should explore whether digital platforms (e.g., video calls or apps) could further enhance the blended model.
Conclusion
The trial by Chang et al. confirms that a blended delivery of parenting programs through primary health care is not only feasible but effective in improving child development and parenting quality. This model provides a vital middle ground between resource-intensive home visiting and low-touch digital interventions. For health policy experts and clinicians, these findings advocate for the integration of parenting support into the primary care continuum as a standard of care for optimizing early childhood outcomes.
Funding and Trial Registration
This study was supported by grants from the Inter-American Development Bank and the Caribbean Child Development Centre. The trial is registered with the ISRCTN Registry (Identifier: ISRCTN11059214).
References
1. Chang SM, Smith JA, Wright AS, et al. Blended Delivery of a Primary Care Parenting Program for Child Development: A Randomized Clinical Trial. JAMA Netw Open. 2026;9(2):e2556024. doi:10.1001/jamanetworkopen.2025.56024.
2. Walker SP, Wachs TD, Grantham-McGregor S, et al. Inequality in early childhood: risk and protective factors for early child development. Lancet. 2011;378(9799):1325-1338.
3. Grantham-McGregor SM, Powell CA, Walker SP, Himes JH. Nutritional supplementation, psychosocial stimulation, and mental development of stunted children: the Jamaican Study. Lancet. 1991;338(8758):1-5.

