Comparison of BMI and Weight-for-Age as a Growth Assessment of Preterm Infants
Disciplines
Applied Statistics
Abstract (300 words maximum)
Objective To evaluate BMI as a complementary measure of growth to weight-for-age for infants in the NICU (neonatal intensive care unit).
Study Design This was an analysis based on Olsen 2009 study of infants (n = 211,237) of gestational age 22 to 42 weeks at birth, born from 2013-2016, having growth data at birth and discharge. Both measurements weight-for-age and BMI were categorized as small (<10th percentile), appropriate (10th-90th percentile), and large ( > 90th percentile).
Results The percentage of infants classified as large-for-age by BMI greatly increased between birth and discharge for infants at gestational age classification of extremely, very and moderately preterm. There was a decrease in agreement from birth to discharge between weight-for-age and BMI. At birth, there was a moderate agreement (K=0.55) while at discharge there was fair agreement (K=0.34). When comparing the percentage of infants categorized as large from birth to discharge, BMI showed a notable increase not seen with weight-for-age. There was moderate agreement for both weight-for-age at birth and discharge (K=0.60) and BMI at birth and discharge (K=0.52).
Conclusions Weight-for age does not classify infant growth the same as BMI. Specifically, it underestimates size for gestational age classification for extremely, very, and moderately preterm infants.
Academic department under which the project should be listed
CCSE - Data Science and Analytics
Primary Investigator (PI) Name
Louise Lawson
Additional Faculty
Amanda Ferguson, afergu10@kennesaw.edu
Comparison of BMI and Weight-for-Age as a Growth Assessment of Preterm Infants
Objective To evaluate BMI as a complementary measure of growth to weight-for-age for infants in the NICU (neonatal intensive care unit).
Study Design This was an analysis based on Olsen 2009 study of infants (n = 211,237) of gestational age 22 to 42 weeks at birth, born from 2013-2016, having growth data at birth and discharge. Both measurements weight-for-age and BMI were categorized as small (<10th >percentile), appropriate (10th-90th percentile), and large ( > 90th percentile).
Results The percentage of infants classified as large-for-age by BMI greatly increased between birth and discharge for infants at gestational age classification of extremely, very and moderately preterm. There was a decrease in agreement from birth to discharge between weight-for-age and BMI. At birth, there was a moderate agreement (K=0.55) while at discharge there was fair agreement (K=0.34). When comparing the percentage of infants categorized as large from birth to discharge, BMI showed a notable increase not seen with weight-for-age. There was moderate agreement for both weight-for-age at birth and discharge (K=0.60) and BMI at birth and discharge (K=0.52).
Conclusions Weight-for age does not classify infant growth the same as BMI. Specifically, it underestimates size for gestational age classification for extremely, very, and moderately preterm infants.