Rates of neonatal abstinence syndrome and maternal opioid-related diagnoses have grown significantly between 2010 and 2017, with both national and state-level increases, according to study results published in JAMA.
To evaluate these changes, researchers conducted a repeated cross-sectional analysis using anonymized data from the Healthcare Cost and Utilization Project’s National Inpatient Sample and State Inpatient Databases. Data from this study included information from community nonrehabilitation hospitals in 47 states and the District of Columbia.
Primary study outcomes included rates of neonatal abstinence syndrome and maternal opioid-related diagnoses; secondary outcomes included length of hospital stay and associated costs. These data were collected in order to evaluate resource utilization patterns.
Data from 2017 identified 751,037 sampled birth hospitalizations and 5375 newborns with neonatal abstinence syndrome; during the same year, 748,239 sampled delivery hospitalizations and 6065 women with maternal opioid-related diagnoses were identified.
Mean gestational age was 38.4 weeks, while mean maternal age at delivery was 28.8 years. Newborns with neonatal abstinence syndrome were significantly more likely to be non-Hispanic White and Medicaid-billed; they were also more likely to live in zip codes with the lowest quartile of median income in nonmetropolitan counties (77.5%, 84%, 38.1%, and 22.1%, respectively).
Between 2010 and 2017, estimated neonatal abstinence syndrome rates significantly increased from 4.0 to 7.3 per 1000 birth hospitalizations (absolute increase, 3.3 per 1000 birth hospitalizations; 95% CI, 2.5-4.1; relative increase, 82%; 95% CI, 57%-107%).
Estimated rates of maternal opioid-related diagnoses also significantly increased, from 3.5 to 8.2 per 1000 delivery hospitalizations, with an absolute increase of 4.6 (95% CI, 3.9-5.4) and a relative increase of 131% (95% CI, 101%-161%). With the release of new ICD-10-CM codes in 2016, larger increases were seen for maternal opioid-related disorders than for neonatal abstinence syndrome.
Estimated rates of maternal opioid-related diagnoses in 2017 were highest among people who were non-Hispanic White and Medicaid-billed, who resided in zip codes in the lowest income quartile, and who were rural residents. Rates were lowest among people who were non-Hispanic Asian/Pacific Islander and privately billed, who lived in zip codes in the highest income quartile, and who were urban residents in large metropolitan areas.
Both mothers and newborns in these categories used significantly more hospital resources, with a significantly longer estimated median length of stay for neonates with neonatal abstinence syndrome and a higher estimated median cost compared with other birth and delivery hospitalizations.
On the state level, West Virginia and Vermont had the highest rates of neonatal abstinence syndrome and maternal opioid-related diagnoses (53.5 per 1000 birth hospitalizations and 47.3 per 1000 delivery hospitalizations, respectively). Maine, Vermont, Delaware, and Kentucky also exceeded neonatal abstinence syndrome rates of 20 per 1000 birth hospitalizations, while West Virginia, Maine, Delaware, and Kentucky exceeded maternal opioid-related diagnoses rates of 20 per 1000 delivery hospitalizations.
Rates of both conditions increased significantly on the state level between 2010 and 2017 except for Nebraska and Vermont, which had increases in only maternal opioid-related diagnoses.
Study limitations include limited sensitivity in hospital discharge data, especially for maternal opioid-related diagnoses, the potential underestimation of neonatal abstinence syndrome, and missing data from Alabama, Idaho, and New Hampshire as well as from federal facilities.
“For the mother-infant dyad, opioid misuse and exposure is associated with adverse outcomes,” the researchers concluded. “Although this study investigated changes in state rates…it did not investigate underlying causes for these changes. Many states have implemented various strategies to address opioid misuse and dependence…specifically among pregnant women and infants, the effect of which could be investigated in future research.”
Hirai AH, Ko JY, Owens PL, Stocks C, Patrick SW. Neonatal abstinence syndrome and maternal opioid-related diagnoses in the US, 2010-2017. JAMA. 2021;325(2):146-155. doi:10.1001/jama.2020.24991