Harmonizing measurements: establishing a common metric via shared items across instruments

Table 1 Number of measurements by study and age range for three studies and four instruments

		Age range of respondents (years)
Country	Study	0–1	1–2	2–3	> 3	N	Instruments
Colombia	GCDG-COL-LT42M	215	417	450	229	1311	BSID-III, Denver, ASQ
Ethiopia	GCDG-ETH	115	75	440	456	1086	BSID-III
Netherlands	GCDG-NLD-SMOCC	10,110	5120	1308	0	16,538	DDI
Total		10,440	5612	2198	685	18,935

BSID-III = Bayley Scales of Infant and Toddler Development, third edition [1]; Denver = Denver Developmental Screening test [6]; ASQ = Ages and Stages Questionnaire [24]; DDI = Development Instrument [30]

ISSN: 1478-7954