The aim of this study is to conduct a hybrid effectiveness/implementation assessment of the International Guide for Monitoring Child Development (GMCD) in two LMIC settings, India and Guatemala, within established rural CHW programs. The primary objectives are (a) to evaluate the real-world effectiveness of the GMCD; (b) to use an implementation science framework to understand barriers and facilitators to effective population coverage, provider implementation, and maintenance; (c) to conduct an economic evaluation of the GMCD.

Specific Aim 1: Assess the effectiveness of the GMCD intervention to improve developmental outcomes and nurturing care in India and Guatemala. The investigators will conduct a parallel-arm cluster randomized trial within rural CHW programs. In the primary effectiveness phase, children under 2 years old will receive the GMCD intervention or control for 12 months. Subsequently, control clusters will cross into the intervention, and continue an additional 12 months (total 24 study months). The primary developmental effectiveness outcome will be change in age-adjusted scores at 12 months on the Bayley Scales of Infant Development, 4th Edition BSID4) (3). The secondary nurturing care effectiveness outcome will be change in mean Home Observation for Measurement of the Environment (HOME) score at 12 months (4).

Specific Aim 2: Assess barriers and facilitators to GMCD implementation using the RE-AIM evaluation framework (5). RE-AIM domains will be assessed as: (a) Reach: participation rates, comparison of participant/non-participant characteristics, attendance/drop-out; (b) Effectiveness: impact on development (BSID4) and nurturing environment (HOME) [in Aim 1]; (c) Adoption: proportion of workers/facilities participating, CHW characteristics; (d) Implementation: contact hours/visit completion, fidelity to delivery protocols; (e) Maintenance: patient outcomes and cost effectiveness analysis at 12-24 months [in Aim 3]; intent by decision makers and implementers to continue intervention. In addition, the investigators will conduct a sequential quantitative-->qualitative explanatory analysis, using interviews and focus groups with implementers from clusters with highest/lowest impact outcomes (BSID4/HOME) to explore institutional inner and outer setting and implementation processes associated with intervention success, using the Consolidated Framework for Implementation Research (CFIR).

Specific Aim 3: Conduct an economic evaluation of the GMCD intervention. Evaluation will assess (a) costs of the interventions at 12 and 24 months; and (b) cost-effectiveness of the intervention (dollar per unit increase in BSID or HOME scores) at 12 months. This analysis will provide cost information to policymakers to help guide resource allocation decisions for ECD interventions.

Inclusion Criteria:

• age 0-24 months at the time of enrollment visit
• receiving health services from frontline health workers of Maya Health Alliance (Guatemala), Mahatma Gandhi Institute (India) or their local partners

Exclusion Criteria:

• children who are critically ill and are judged by the frontline health worker to require hospitalization or center-based care
• children whose caregivers do not provide informed consent for the study

Investigators will deposit the above data in the Harvard Dataverse (https://dataverse.harvard.edu/) or another suitable public data repository, and it will be freely available there for any researcher wishing to perform secondary analysis, confirmation of primary study findings, or meta-analysis who adheres to the existing policy and procedures of the repository.

Investigators will submit data sets to the repository no later than 3 years after completion of final patient follow-up, or 2 years after the publication of the main study paper, whichever comes first.

Publically available

Given nature of study, blinding is not feasible.