OBJECTIVETo introduce the Ages and Stages Questionnaires, Third Edition (ASQ-3), to China, created ASQ-Chinese (ASQ-C) and carried out studies of its national norm and the psychometrical properties in the children aged 1-66 months in the mainland of China in collaboration with the author of the ASQ System and under the authorizations from its publisher on translation, researches, publication and distribution of the ASQ-3.

METHODThe ASQ-3 questionnaires were translated and adapted into a Simplified Chinese version, the ASQ-C, with six steps such as translation, back-translation and adaptation and so on to ensure consistency with the core of the original document and to have the cultural relevance in China.A stratified cluster sampling method was utilized to recruit children aged 1-66 months with respect to demographic characteristics such as the proportion of population in each administrative region and in urban and rural areas and so on that are representative of 2010 China census data.A sample size of over 200 was collected for each ASQ-C age interval.Children were excluded from the normative sample who (1) are from communities or villages at an elevation of 2 000 m or above and(or) where simplified Chinese is not the official language, or (2) had been diagnosed as having a developmental delay by any authoritative organizations.The national normative sample for the ASQ-C had a total sample size of 4 452, sample size within each age interval ranged from 218 to 227, including 2 230 male cases and 2 222 female cases, 2 236 urban cases and 2 216 rural cases.A convenience sample was recruited from the normative sample to examine inter-rater reliability and test-retest reliability in all six administrative regions.Researchers completed the ASQ-C on the same child with their parents for 162 children for inter-rater reliability(the size of each ASQ-C age interval was 5-9); parents of 168 children completed another age-appropriate ASQ-C for test-retest reliability during 10-15 days after they completed the normative ASQ-C(The size of each ASQ-C age interval is 6-10). Another convenience sample was recruited from the follow-up of low birth weight infants for the concurrent validity of the ASQ-C in comparison with the Beijing Gesell.Parents of 198 children completed age-appropriate ASQ-C and professional administered to the children with the Beijing Gesell.In the ASQ-C norm and test-retest reliability, parents completed the age-appropriate ASQ-C, independently or with needed assistance. In inter-rater reliability, researchers completed the same ASQ-C after parents. In validity test, after parents completing age-appropriate ASQ-C, professional tested children with the Beijing Gesell.Data were analyzed using SPSS version 13.0 software.The mean and standard deviation of the national normative sample were calculated, reliability and validity of the ASQ-C was examined.

RESULTThe demographic characteristics of this Chinese sample match the 2010 China census data on gender, urban or rural location, and family income.All 20 intervals of the ASQ-C were standardized on 21 national normative samples.Cronbach's alpha coefficient for the whole measure was 0.8.The Pearson correlation coefficient between the ASQ-C total scores of the two raters was 0.8.The Pearson correlation coefficient between the ASQ-C total scores of the two times was 0.8 (all P<0.000 1). The sensitivity of ASQ-C was 87.50% and the specificity of ASQ-C was 84.48%.The percentage of the agreement between the ASQ-C and the Beijing Gesell was 84.74%.

CONCLUSIONThese findings indicate that the ASQ-C is a reliable and valid measure with a representative national sample aged 1-66 months.It can be used to screen and monitor the development of children in the mainland of China.