PMID- 31803508 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20240205 IS - 2059-7908 (Print) IS - 2059-7908 (Electronic) IS - 2059-7908 (Linking) VI - 4 IP - 6 DP - 2019 TI - The D-score: a metric for interpreting the early development of infants and toddlers across global settings. PG - e001724 LID - 10.1136/bmjgh-2019-001724 [doi] LID - e001724 AB - 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 (<2500 g) and stunting (-2 SD below median height-for-age). DAZ increased significantly with maternal education in 55% of data rounds. Predictive correlations of DAZ with outcomes obtained 2-16 years later were generally between 0.20 and 0.40. Correlations equalled or exceeded those obtained with original instruments despite using an average of 55% fewer items to estimate the D-score. CONCLUSION: The D-score metric enables quantitative comparisons of early childhood development across ages and sets the stage for creating simple, low-cost, global-use instruments to facilitate valid cross-national comparisons of early childhood development. CI - (c) Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY. Published by BMJ. FAU - Weber, Ann M AU - Weber AM AUID- ORCID: 0000-0001-8130-5858 AD - School of Community Health Sciences, University of Nevada Reno, Reno, Nevada, USA. AD - Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA. FAU - Rubio-Codina, Marta AU - Rubio-Codina M AUID- ORCID: 0000-0002-1286-7918 AD - Inter-American Development Bank, Washington, District of Columbia, USA. FAU - Walker, Susan P AU - Walker SP AD - Caribbean Institute for Health Research, University of the West Indies, Kingston, Jamaica. FAU - van Buuren, Stef AU - van Buuren S AD - Netherlands Organization for Applied Scientific Research TNO, Leiden, Netherlands. AD - Methodology & Statistics, Utrecht University, Utrecht, Netherlands. FAU - Eekhout, Iris AU - Eekhout I AD - Netherlands Organization for Applied Scientific Research TNO, Leiden, Netherlands. FAU - Grantham-McGregor, Sally M AU - Grantham-McGregor SM AD - Institute of Child Health, University College London, London, UK. FAU - Araujo, Maria Caridad AU - Araujo MC AD - Inter-American Development Bank, Washington, District of Columbia, USA. FAU - Chang, Susan M AU - Chang SM AD - Caribbean Institute for Health Research, University of the West Indies, Kingston, Jamaica. FAU - Fernald, Lia Ch AU - Fernald LC AD - School of Public Health, University of California Berkeley, Berkeley, California, USA. FAU - Hamadani, Jena Derakhshani AU - Hamadani JD AD - Maternal and Child Health Division, icddr,b, Dhaka, Bangladesh. FAU - Hanlon, Charlotte AU - Hanlon C AUID- ORCID: 0000-0002-7937-3226 AD - Institute of Psychiatry, Psychology and Neuroscience, Health Service and Population Research Department, Centre for Global Mental Health, King's College London, London, UK. AD - Department of Psychiatry, WHO Collaborating Centre for Mental Health Research and Capacity Building, School of Medicine, and Centre for Innovative Drug Development and Therapeutic Trials for Africa (CDT-Africa), College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia. FAU - Karam, Simone M AU - Karam SM AD - Department of Pediatrics, Federal University of Rio Grande, Rio Grande, Brazil. FAU - Lozoff, Betsy AU - Lozoff B AD - Center for Human Growth and Development, University of Michigan, Ann Arbor, Michigan, USA. FAU - Ratsifandrihamanana, Lisy AU - Ratsifandrihamanana L AD - Centre Medico-Educatif "Les Orchidees Blanches", Antananarivo, Madagascar. FAU - Richter, Linda AU - Richter L AUID- ORCID: 0000-0002-3654-3192 AD - Centre of Excellence in Human Development, University of the Witwatersrand, Johannesburg, South Africa. FAU - Black, Maureen M AU - Black MM AUID- ORCID: 0000-0002-6427-4639 AD - Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA. AD - International Education, RTI International, Research Triangle Park, North Carolina, USA. CN - Working group members and data contributors LA - eng GR - WT_/Wellcome Trust/United Kingdom PT - Journal Article DEP - 20191119 PL - England TA - BMJ Glob Health JT - BMJ global health JID - 101685275 PMC - PMC6882553 OTO - NOTNLM OT - child development OT - global health OT - item response theory OT - psychometrics COIS- Competing interests: CH receives support from the African Mental Health Research Initiative (AMARI) as part of the Wellcome Trust-funded DELTAS Africa Initiative [DEL-15-01]. The original data collected in Ethiopia was funded by the Wellcome Trust (project grant 093559). FIR - Attanasio, Orazio IR - Attanasio O FIR - Darmstadt, Gary L IR - Darmstadt GL FIR - Doove, Bernice M IR - Doove BM FIR - Galasso, Emanuela IR - Galasso E FIR - Jervis, Pamela IR - Jervis P FIR - Medhin, Girmay IR - Medhin G FIR - Menezes, Ana M B IR - Menezes AMB FIR - Pitchik, Helen IR - Pitchik H FIR - Reynolds, Sarah IR - Reynolds S FIR - Schady, Norbert IR - Schady N EDAT- 2019/12/06 06:00 MHDA- 2019/12/06 06:01 PMCR- 2019/11/19 CRDT- 2019/12/06 06:00 PHST- 2019/05/20 00:00 [received] PHST- 2019/08/28 00:00 [revised] PHST- 2019/08/30 00:00 [accepted] PHST- 2019/12/06 06:00 [entrez] PHST- 2019/12/06 06:00 [pubmed] PHST- 2019/12/06 06:01 [medline] PHST- 2019/11/19 00:00 [pmc-release] AID - bmjgh-2019-001724 [pii] AID - 10.1136/bmjgh-2019-001724 [doi] PST - epublish SO - BMJ Glob Health. 2019 Nov 19;4(6):e001724. doi: 10.1136/bmjgh-2019-001724. eCollection 2019.