Abstract
Objective This study aimed to determine the factors associated with positive infant drug screen
and create a shortened screen and a prediction model.
Study Design This is a retrospective cohort study of all infants who were tested for drugs of
abuse from May 2012 through May 2014. The primary outcome was positive infant urine
or meconium drug test. Multivariable logistic regression was used to identify independent
risk factors. A combined screen was created, and test characteristics were analyzed.
Results Among the 3,861 live births, a total of 804 infants underwent drug tests. Variables
associated with having a positive infant test were (1) positive maternal urine test,
(2) substance use during pregnancy, (3) ≤ one prenatal visit, and (4) remote substance
abuse; each p-value was less than 0.0001. A model with an indicator for having at least one of
these four predictors had a sensitivity of 94% and a specificity of 69%. Application
of this screen to our population would have decreased drug testing by 57%. No infants
had a positive urine drug test when their mother's urine drug test was negative.
Conclusion This simplified screen can guide clinical decision making for determining which infants
should undergo drug testing. Infant urine drug tests may not be needed when a maternal
drug test result is negative.
Key Points
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Many common drug screening criteria are not predictive.
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Four criteria predicted positive infant drug tests.
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No infant urine drug test is needed if the mother tests negative.
Keywords
prediction model - drug tests - newborns - substance use disorder
