Background:
The majority of infants who die in the neonatal period are born with a low birth weight (LBW, <2500
grams), or prematurely (before 37 weeks). Most deaths among these infants could be prevented with simple, low-cost
interventions like kangaroo mother care (KMC) or prevention and early identification of infection. It is difficult, however,
to determine birth weight and gestational age in community settings, and therefore necessary to find an appropriate
alternative screening tool that can identify LBW and preterm infants.
Methods:
This cross-sectional study was conducted at a tertiary hospital in Nepal to compare the validity of using three
different foot length measurement methods (plastic ruler, measuring tape, and paper footprint) as screening tools for
identifying babies with birth weights <2000 grams or infants born preterm (<37 weeks). LBW was defined as less than
2000 grams because of the implication for use of KMC for these inf
ants. Non-parametric receiver operating characteristics
(ROC) analysis was completed to determine which measure
ment method best predicted L
BW and preterm birth. For the
method that was the best predictor for each outcome (i.e. high
est area under the curve), further analyses were completed
to determine sensitivity, specificity, likelihood ratios and predictive values of an operational screening cutoff to predict
LBW or preterm birth in this setting.
Results:
Of the 811 infants included in this study, 30 infants had LBW and 54 were born preterm. The plastic ruler was
the measurement method with the highest area under the curv
e, and thus predictive score for estimating both outcomes,
so operational cutoffs were identified based on this method. An operational cutoff of 7.2 cm was identified to screen
for infants weighing <2000 grams at birth (sensitivity: 75.
9%, specificity: 90.3%), and 7.8 cm was determined as the
operational cutoff to identify preterm infants (sensitivity: 76.9%, specificity: 53.9%).
Conclusions:
In Nepal, at least in community settings, foot length measurement with a hard ruler may be a valid
proxy to identify at-risk infants when birth weight or gestational age is unavailable. Further studies and piloting should
be conducted to identify exact cutoffs that can be used within community settings.