Internal consistency and concurrent validity of the Peruvian Infant Development Scale tool in high-altitude rural Andean Peru

BackgroundMeasuring the developmental status of children living in low- and middle-income countries is a major challenge. The Peruvian Infant Development Scale (ESDI) is a screening instrument used for children under 36 months of age. The ESDI has been validated in Peru, but its psychometric properties have not been yet compared with international instruments. MethodsIn rural Andean Peru, we compared ESDI scores with those of the Bayley Scales of Infant Toddler Development (BSID) to investigate the internal consistency and concurrent validity of the ESDI. Internal consistency was assessed using standardised Cronbachs alpha coefficients () and item-test correlations. We examined the concurrent validity of cognitive, motor, and communication domains using Pearson correlations (r) and bootstrapping methods in children aged 19-30 months and 31-36 months. We also examined the relationship between the developmental domains, maternal education, and household wealth. ResultsWe compared information from 167 children. Internal consistency and reliability were acceptable for both the ESDI (=0.75; item-test: 0.68-0.85) and the BSID (=0.91; item-test: 0.82-0.90). In children aged 19-30 months, we found weak correlations for the cognitive (r=0.04; p>0.05) and motor (r=-0.04-0.11; p>0.05) domains, and moderate-to-strong correlations for the communication domain (r=0.42-0.57; p<0.05). At 31-36 months of age, we found moderate correlations for the cognitive (r=0.46; p<0.05) and communication (r=0.37-0.44; p<0.05) domains, and weak-to-moderate correlations for the motor domain (r=0.22-0.31; p<0.05). The ESDI and BSID domains were equally correlated with maternal education and household wealth. ConclusionsThe ESDI is a useful instrument for assessing the developmental status of children, especially those over 30 months of age. Due to its free cost, short duration, and simple administration, the ESDI is suitable for resource-poor settings in Peru. The ESDI can be strategically scaled through the Peruvian ECD programme Cuna Mas, so that this intervention can be adequately monitored in a cost-effective manner.