Developmental assessment of preterm infants: Chronological or corrected age?
Score the Mullen with corrected age for any baby born early and you will see fewer false delays.
01Research in Context
What this study did
The team gave the Mullen Scales of Early Learning to preterm babies.
They scored the same babies twice: once by birth age and once by corrected age.
They tracked kids from 1 month to 24 months to see which score painted the true picture.
What they found
Corrected-age scores were higher at every visit.
Fewer babies were tagged with delay when the test used corrected age.
The gap stayed wide all the way to the second birthday.
How this fits with other research
Witt et al. (2020) found the same rule works for older kids with ID.
When tasks were matched to mental age instead of birth age, children with ID learned new words just like mental-age peers.
The two studies line up: use developmental age, not calendar age, when you test.
Carmichael et al. (1999) seems to disagree.
They showed that, in school-age clients with ID, older chronological age still predicted stronger crystallized intelligence.
The difference is age range.
Corrected age matters most in babies.
After early childhood, extra years of life do add knowledge, so chronological age starts to count again.
Why it matters
If you give the Mullen to a preterm infant, always subtract the weeks of early birth before you look up the score.
That single step prevents false delay labels and keeps families from needless stress.
Add a note in your report template so no one on your team forgets.
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02At a glance
03Original abstract
The aim of this study is to examine the effect of age correction on the developmental assessment scores of preterm infants, using for the first time, the Mullen scales of early learning (MSEL) test. Participants included 110 preterm infants (born at a gestational age of ≤ 34 weeks) at ages 1, 4, 8, 12, 18, 24 and 36 months. The corrected age-based MSEL composite score and each of the five MSEL scale scores were significantly higher than chronological age-based scores at all ages. These corrected scores were significantly higher than the chronological scores regardless of gestational age whether weight was, or adequate or small for gestational age. Larger differences between corrected and chronological age-based scores significantly correlated with earlier gestational age and with lower birth weight between 1 and 24 months but not at 36 months. Using chronological age-based scores yielded significantly more infants identified with developmental delays than using corrected age-based scores. The findings indicate that clinicians and researchers, as well as family members, should be aware of and acknowledge the distinction between corrected and chronological ages when evaluating preterm infants in research and clinical practices.
Research in developmental disabilities, 2018 · doi:10.1016/j.ridd.2018.06.002