PURPOSE: A simplified approach to determining the severity of narcotic withdrawal in newborns was developed and compared to the dominant measure of newborn withdrawal. Reliability, specificity and sensitivity of the new measure were determined.

METHODS: A method of rating the symptomatic behavior of infants exposed to narcotics was developed and standardized. Reliability and validity studies were carried out. In study A, four nurses successively administered both the Neonatal Abstinence Scoring System (NASS) and the newly developed measure of infant withdrawal - the Narcotic Withdrawal Inventory (NWI) to 30 newborns. Inter-rater and overall reliability of the two measures was compared, as well as the time required to perform the tests. In study B, blinded scoring of 50 infants was done with the NWI and compared to the NASS scores recorded by nursing staff in patients' charts.

RESULTS: Inter-rater reliability for the NWI ranged from.89 to.98 and from.70 to.88 for the FNAS. Cronbach coefficients for the NWI and NASS were.98 and.93, respectively. The NWI required (5 min.) half as much time to complete as the NASS. Of the 29 subjects scoring <8 (below treatment threshold) on the NASS, 29 also had NWI scores <8 on the NWI, indicating specificity of 100%. 21 subjects with NASS scores ≥ 8 also achieved NWI scores ≥ 8, for a sensitivity of 100%. κ= 1.0, with a standard error of.14.

CONCLUSION: When compared to the dominant method for scoring withdrawal severity in newborns, the Neonatal Withdrawal Inventory was determined to be highly reliable, sensitive and specific as a diagnostic method. The NWI's advantages include brevity, ease of administration, and flexibility. Accurate, objective and individualized assessment of neonatal withdrawal severity can be carried out in ten minutes under case-blinded conditions with the NWI. The NWI's simplicity and accuracy commend its wider use as a clinical and experimental tool.