Telephone versus in-person administration of the Early Childhood Development Index 2030: a crossover study, Brazil,...

To examine agreement between telephone and in-person administration of the Early Childhood Development Index 2030 (ECDI2030) survey.

In this crossover study, we compared in-person ECDI2030 interviews with other modalities (primarily telephone-based interviews) selected at a country level in Brazil, Canada, India and Malawi. Eligible participants were primary caregivers of preschool-aged children (36-60 months old), with equal recruitment across child sex and urban and rural residence. The primary outcome was agreement in overall scores between in-person interviews and other tested modalities, assessed using paired t-tests and intraclass correlation coefficients.

The analytical sample included 258 individuals, with 212 paired observations for in-person and telephone-based interviews. Pooled t-tests showed no significant differences in overall scores between the interview modalities. However, in-person interviews yielded slightly higher scores than telephone interviews for female children (mean difference: 0.23; Cohen's d _diff: 0.22) and participants from India (mean difference: 0.47; Cohen's d _diff: 0.44). Canadian participants had lower scores on the second assessment completed (mean difference: -0.27; Cohen's d _diff: -0.36), regardless of modality. However, pooled and stratified intraclass correlation coefficients analyses indicated that these modalities were statistically similar, with values ranging from 0.89 to 0.93, which are values commonly categorized as good to excellent.

This multinational, multicentre, crossover study shows high agreement between telephone and in-person administration of the ECDI2030 across economically, culturally and geographically diverse settings. Expanding administration modalities may improve feasibility, particularly in geographically dispersed populations and rural settings.