Table 2

Development and validation of the Global Scale for Early Development

Methodology for prototype creationValidation
  • Culturally neutral, minimal adaptation required.

  • Psychometrically sound, including concurrent, discriminant and predictive validity.

  • Sensitive to child age and environment.

  • Amenable to improvements.

  • Feasibly administered.

  • Minimal training required.

  • Interpretable by policy makers.

  • Open access, no/limited cost (training, materials).

  • Could be used to develop norms.

  • Creation of a common data set from three initiatives (IYCD, CREDI and D-score).

  • Harmonisation of data sets generated from the use of 22 instruments (2275 items) administered to 73 222 children (a total of 109 079 visits, and unique child/age combinations) within 51 cohorts.

  • Items selected by matching ratings of subject matter experts with instrument prototypes based on construction of a latent scale of childhood development using optimal statistical modelling approaches (Rasch vs a two-parameter model).

  • Simulations of expected psychometric properties of the instruments based on existing data set.

  • Field testing to verify the properties of both instruments, in accordance with the predefined characteristics.

  • CREDI, Caregiver-Reported Early Development Instrument; D-score, Developmental Score; IYCD, Infant and Young Child Development.