Concurrent validity of ages and stages questionnaires in preterm infants.

BACKGROUND

Although preterm infants born at 29 to 36 gestational weeks (GW) are at risk for developmental delay, they do not always benefit from systematic follow-up. Primary care physicians are then responsible for their developmental surveillance and need effective screening tests. This study aimed to determine whether the Ages and Stages Questionnaires (ASQ) at 12 and 24 months' corrected age (CA) identify developmental delay in preterm infants.

METHODS

With a cross-sectional design involving 2 observations at 12 and 24 months' CA, 124 and 112 preterm infants were assessed. Infants were born between May 2004 and April 2006 at 29 to 36 GW. The ASQ and the Bayley Scales of Infant Development were used. Concurrent validity was calculated by using κ coefficient, sensitivity, and specificity.

RESULTS

At 12 months' CA, the ASQ did not perform well in identifying infants with mental delay (κ = 0.08-0.19; sensitivity = 0.20-0.60; specificity = 0.68-0.88). Agreement (κ = 0.28-0.44) and specificity (0.90-0.97) were better for the psychomotor scale, but the sensitivity remained insufficient (0.25-0.52). At 24 months, the ASQ had good sensitivity (0.75-0.92) and specificity (0.55-0.78) for detecting mental delays (κ = 0.45). Results remained unsatisfactory for detecting motor delays (sensitivity = 0.31-0.50; specificity = 0.73-0.92).

CONCLUSIONS

Preterm infants with developmental delays at 12 months' CA are not adequately identified with the ASQ. At 24 months' CA, the ASQ identifies mental delays but not psychomotor delays. Additional measures should be used to increase yield of detecting at-risk preterm infants.