Title
The D-score: a metric for interpreting the early development of infants and toddlers across global settings
Author
Weber, A.M.
Rubio-Codina, M.
Walker, S.P.
van Buuren, S.
Eekhout, I.
Grantham-Mcgregor, S.M.
Araujo, M.C.
Chang, S.M.
Fernald, L.C.H.
Hamadani, J.D.
Hanlon, C.
Karam, S.M.
Lozoff, B.
Ratsifandrihamanana, L.
Richter, L.
Black, M.M.
Publication year
2019
Abstract
Introduction Early childhood development can be described by an underlying latent construct. Global comparisons of children's development are hindered by the lack of a validated metric that is comparable across cultures and contexts, especially for children under age 3 years. We constructed and validated a new metric, the Developmental Score (D-score), using existing data from 16 longitudinal studies. Methods Studies had item-level developmental assessment data for children 0-48 months and longitudinal outcomes at ages >4-18 years, including measures of IQ and receptive vocabulary. Existing data from 11 low-income, middle-income and high-income countries were merged for >36 000 children. Item mapping produced 95 'equate groups' of same-skill items across 12 different assessment instruments. A statistical model was built using the Rasch model with item difficulties constrained to be equal in a subset of equate groups, linking instruments to a common scale, the D-score, a continuous metric with interval-scale properties. D-score-for-age z-scores (DAZ) were evaluated for discriminant, concurrent and predictive validity to outcomes in middle childhood to adolescence. Results Concurrent validity of DAZ with original instruments was strong (average r=0.71), with few exceptions. In approximately 70% of data rounds collected across studies, DAZ discriminated between children above/below cut-points for low birth weight (
Subject
hild development
Global health
Item response theory
Psychometrics
To reference this document use:
http://resolver.tudelft.nl/uuid:c4f6a2d6-a2a2-4f36-b8b2-ba3b3caf079c
DOI
https://doi.org/10.1136/bmjgh-2019-001724
TNO identifier
870322
ISSN
2059-7908
Source
BMJ Global Health, 4 (4)
Document type
article