2.3 Instruments

The Bayley Scales for Infant and Toddler Development (by1,by2, by3) aim to assess infants and toddlers, aged 1-42 months. The current version is the by3, but some GCDG cohorts used earlier versions (i.e. by1 and by2) (Bayley 1969)(Bayley 1993)(Bayley 2006). The 326 items of the by3 measure three domains: Cognitive items, Motor items (with fine and gross motor items), and Language items (with expressive and receptive items). The by2 contains 277 items and has two additional subscales: Social-Emotional and Adaptive Behavior. by1 contains 229 items.

The Denver Developmental Screening Test (den) is aimed to identify developmental problems in children up to age six. The 125 dichotomous test items are distributed over the age range from birth to six years. The Denver covers four domains: personal-social, fine motor and adaptive, language, and gross motor. The test items are all directly observed by an examiner and are not dependent on parent report (Frankenburg et al. 1992) (Frankenburg et al. 1990).

The Griffiths Mental Development Scales (gri) measure the rate of development in infants and young children in six developmental areas: locomotor, personal-social, hearing and language, eye and hand coordination, performance and practical reasoning (Griffiths 1967).

The Battelle Developmental Inventory (bat) measures key developmental skills in children from birth to 7 years, 11 months. The instrument contains 450 items distributed over five domains: adaptive, personal-social, communication, motor, and cognitive (Newborg 2005).

The Vineland Social Maturity Scale (vin) is a test to assess social competence. The instrument contains eight subscales that measure communication skills, general self-help ability, locomotion skills, occupation skills, self-direction, self-help eating, self-help dressing and socialisation skills (Doll 1953).

The Dutch Developmental Instrument (ddi) measures early child development during the ages 0-4 years. The instrument consists of 75 milestones spread over three domains: fine motor, adaptive, personal and social behaviour; communication; and gross motor (Schlesinger-Was 1981).

The Barrera Moncada (bar) is a Spanish instrument that measures the growth and psychological development of children (Barrera Moncada 1981).

The Test de Desarrollo Psicomotor (tep) is an instrument to evaluate toddlers aged 2 to 5 years on their development. The items come from three sub-tests: 16 items assess coordination; 24 items measure language skills and 12 items tap into motor skills (Haeussler and Marchant 1999).

The Ages and Stages Questionnaire (aqi) measures developmental progress in children aged 2 mo – 5.5 yrs. The instrument distinguishes development in five areas: personal-social, gross motor, fine motor, problem solving, and communication. The caregiver completes 30 items per age intervals and (Squires and Bricker 2009).

The Stanford Binet Intelligence Scales (sbi) is a cognitive ability and intelligence test to diagnose developmental deficiencies in young children. The items divide into five subtests: fluid reasoning, knowledge, quantitative reasoning, visual-spatial processing, and working memory (Roid 2003)(Hagen and Stattler 1986).