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INTER-NDA Standards

The INTER-NDA is a 37 item assessment of cognition, language, fine  motor skills, gross motor skills, positive behaviour, and negative behaviour. It consists of directly administered, concurrently observed and maternally reported items. Trained and standardized assessors report on a child's performance on a 5-point scale. Emphasis is placed on the objective reporting of the child's performance rather than the assessor's subjective judgement of the same. Data are collected either via paper forms or a web-based E-form. The INTER-NDA has good reliability across international settings and has been validated against the Bayley Scales. Its norms are the first international standards of early child development at age 2 years and have been developed from 5 international populations using the WHO's prescriptive methodology for the construction of biological standards.

Age range: 22 to 30 months

Assessment time: 15 minutes 

Level of professional qualification of assessors: None, can be administered by trained non-specialists

Suitable for: High, middle and low income populations; clinical and research settings as well as population-level surveillance

Cut-offs: The threshold of normality is >10th centile for all domains except negative behaviour where the threshold for normality is <90th centile. The threshold for mild to moderate and severe delay is the 3rd to 10th and <3rd centiles, respectively, for all domains except negative behaviour where these thresholds are >97th and 90th to 97th centiles respectively. 


The INTERGROWTH-21st Project Neurodevelopment Package: a novel method for the multi-dimensional assessment of neurodevelopment in pre-school age children. Fernandes M, Stein A, Newton CR, Cheikh-Ismail L, Kihara M, Wulff K, de León Quintana E, Aranzeta L, Soria-Frisch A, Acedo J, Ibanez D, Abubakar A, Giuliani F, Lewis T, Kennedy S, Villar J; International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH-21st). PLoS One. 2014 Nov 25;9(11):e113360.

Fernandes M, Villar J, Stein A, Urias ES, Garza C, Victora CG, Barros FC, Bertino E, Purwar M, Carvalho M, Giuliani F. INTERGROWTH-21st Project international INTER-NDA standards for child development at 2 years of age: an international prospective population-based study. BMJ Open. 2020 Jun 1;10(6):e035258.

Villar J, Fernandes M, Purwar M, Staines-Urias E, Di Nicola P, Ismail LC, Ochieng R, Barros F, Albernaz E, Victora C, Kunnawar N. Neurodevelopmental milestones and associated behaviours are similar among healthy children across diverse geographical locations. Nature communications. 2019 Jan 30;10(1):1-0.

Villar J, Ismail LC, Urias ES, Giuliani F, Ohuma EO, Victora CG, Papageorghiou AT, Altman DG, Garza C, Barros FC, Puglia F…Fernandes M, Bhutta Z and Kennedy S. The satisfactory growth and development at 2 years of age of the INTERGROWTH-21st Fetal Growth Standards cohort support its appropriateness for constructing international standards. American journal of obstetrics and gynecology. 2018 Feb 1;218(2):S841-54.