Reliability and agreement of ages and stages questionnaires®: Results in late preterm and term-born infants at 24 and 48 months.

Aim: To evaluate the reliability of the Ages and Stages Questionnaires (ASQ-3) 24 and 48 month intervals translated to Spanish by Brookes Publishing, and the agreement between both questionnaires, comparing late preterm (LPI) and term-born infants (terms).

Methods: Two cohort samples of healthy LPI and terms that were born in a private hospital in Barcelona, Spain. Internal consistency was analyzed by Cronbach's alpha scores and Pearson product- moment correlation between the domain scores and the overall score. The agreement was analyzed using Pearson's correlations between the two questionnaires, and the odds ratio (OR) for positive screening at 48 months, given a positive screen in 24 month assessment.

Results: A total of 473 evaluations were analyzed, representing 331 children. Cronbach's alpha scores for the motor domains on both intervals were low, but acceptable compared with the overall score; a strong positive correlation between the domain and overall score were obtained in the majority of the domains. The correlation between the 24 and 48 month total scores were positive, especially for LPI. Having at least 2 domains in the referral zone at 24 months was associated with an OR of 140 [95% CI 14.85; 3575.65] for positive screen at 48 months.

Conclusion: The Spanish ASQ-3 24 and 48 month intervals appear to be a reliable for developmental screening and for the follow-up of children, especially for LPI. Having two or more domains in the referral zone at 24 months screening is a significant predictor of developmental delay risk at 48-month questionnaire.