Comparing Attained Weight and Weight Velocity during the First 6 Months in Predicting Child Undernutrition and
Dongqing Wang1, Catherine Schwinger2, Willy Urassa3
1Department of Global Health and Population, Harvard TH Chan School of Public Health, Harvard University, Boston, MA, USA.
Insights
Attained weight is a better predictor of infant undernutrition than weight velocity in the first six months. This finding highlights the importance of tracking infant growth for early risk identification.
Area of Science:
- Pediatrics
- Global Health
- Nutritional Science
Background:
- The first six months of life are critical for infant development and survival.
- Undernutrition and mortality risks are significantly influenced by early growth patterns.
- Predictive accuracy of different infant weight metrics requires comparison.
Purpose of the Study:
- To compare the predictive abilities of attained weight and weight velocity for undernutrition and mortality in infants.
- To evaluate weight-for-age z score (WAZ) and weight velocity z score (WVZ) in early infancy.
Main Methods:
- A cohort of Tanzanian infants was studied from birth to 18 months.
- Monthly weight and length measurements were collected.
- Attained WAZ, change in WAZ, and WVZ were used as predictors for undernutrition and mortality outcomes.
Main Results:
- Attained WAZ showed higher predictive ability for wasting and stunting after two months compared to WVZ.
- Weight velocity z score (WVZ) was a better predictor of wasting at six months in the second month of life.
- All weight metrics demonstrated limited ability in predicting mortality.
Conclusions:
- Attained weight at the end of each month is a more effective predictor of undernutrition than monthly weight velocity.
- Tracking attained weight is crucial for identifying infants at high risk of undernutrition.
- Early growth monitoring is essential for timely intervention.
Background:
The first 6 mo of life are critical for subsequent risk of undernutrition and mortality. The predictive abilities of attained weight at the end of each month and monthly weight velocity for undernutrition and mortality need to be compared.
Objectives:
This study aimed to examine the predictive abilities of different weight metrics during the first 6 mo of life in predicting undernutrition and mortality.
Methods:
This study used a cohort of infants in Tanzania. Weight and length were measured monthly from birth to 18 mo of age. Three weight metrics during the first 6 mo of life were considered as predictors, including attained weight-for-age z score (WAZ) at the end of each month, monthly change in WAZ, and monthly weight velocity z score (WVZ). Logistic models were used with undernutrition (at 6 or 12 mo) and mortality (over the first 18 mo) as outcomes. AUC values were compared across metrics.
Results:
For predicting wasting at 6 mo, WVZ (AUC: 0.80) had a greater predictive ability than attained WAZ (AUC: 0.76) and change in WAZ (AUC: 0.71) during the second month of life. After 2 mo, attained WAZ (AUC: 0.81-0.89) had greater predictive abilities than WVZ (AUC: 0.71-0.77) and change in WAZ (AUC: 0.65-0.67). For predicting stunting at 6 mo, attained WAZ (AUC: 0.75-0.79) had consistently greater predictive abilities than WVZ (AUC: 0.56-0.66) and change in WAZ (AUC: 0.50-0.57). The weight metrics had similar abilities in predicting mortality, with the AUC rarely reaching >0.65.
Conclusions:
Attained weight at the end of each month had greater abilities than monthly weight velocity in the same month in predicting undernutrition. Attained weight remains a useful indicator for identifying infants at greater risk of undernutrition.
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