US neonatal abstinence syndrome, maternal opioid disorder rates on the rise

From 2010 to 2017, estimated rates of neonatal abstinence syndrome and maternal opioid use disorder significantly increased across the United States, data show.

Rates of neonatal abstinence syndrome (NAS) and maternal opioid use disorder (MOD) significantly increased in most states, researchers said — with “notable variation.”

Although previous research has shown that NAS and MOD rates vary between states, the studies were conducted in a “limited number” of states and before the changeover from ICD-9 to ICD-10, Ashley Hirai, PhD, a senior scientist at the Health Resources and Services Administration, and colleagues wrote in JAMA. The newer ICD expanded the number of maternal opioid use codes, they said.

Hirai and colleagues conducted a repeated cross-sectional analysis of the 2010 to 2017 Healthcare Cost and Utilization Project’s National Inpatient Sample and State Inpatient Database, which contains hospital discharge records from community hospitals across all payers in 47 states and the District of Columbia.

In 2017, the database included information from 751,037 birth hospitalizations (instances when ICD-9-CM diagnosis code 779.5 [“drug withdrawal syndrome in newborn”] and ICD-10-CM diagnosis code P96.1 [“neonatal withdrawal symptoms from maternal use of drugs of addiction”] was present on the infant’s discharge record, according to researchers), and 748,239 delivery hospitalizations (defined as diagnoses of opioid dependence and opioid abuse that aligned with the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders criteria and/or where ICD-10-coding indicated long-term use of opioid medications and unspecified opioid use appeared on the mother’s discharge record). Of the totals, 5,375 newborns had NAS documented and 6,065 women (mean gestational age, 38.4 weeks, mean maternal age, 28.8 years) had MOD documented.

The researchers reported that from 2010 to 2017, the estimated rate of NAS increased by 3.3 cases (95% CI, 2.5-4.1) per 1,000 birth hospitalizations — from four cases (95% CI, 3.3-4.7) to 7.3 cases (95% CI, 6.8-7.7). The estimated MOD rate increased by 4.6 cases (95% CI, 3.9-5.4) per 1,000 delivery hospitalizations — from 3.5 cases (95% CI, 3-4.1) to 8.2 cases (95% CI, 7.7-8.7). During the study period, NAS and MOD rates increased significantly in all states except Nebraska and Vermont, both of which only had MOD increases.

In addition, an analysis of 2017 census data from 47 states showed the following states had the highest NAS cases for every 1,000 birth hospitalizations:

• 53.5 in West Virginia (an increase of 283% from 2010);
• 31.4 in Maine (an increase of 48% from 2010);
• 29.4 in Vermont (an increase of 11% from 2010);
• 24.2 in Delaware (data from 2010 unavailable); and
• 23.9 in Kentucky (an increase of 196% from 2010).

A similar analysis showed these states had the highest MOD rates for every 1,000 delivery hospitalizations:

• 47.3 in Vermont (an increase of 75% from 2010);
• 40.1 in West Virginia (an increase of 283% from 2010);
• 37.8 in Maine (an increase of 56% from 2010);
• 24.3 in Delaware (data from 2010 unavailable); and
• 23.4 in Kentucky (an increase of 273% from 2010).

“Between 2010 and 2017, 24 states saw increases of 100% or more for both indicators,” Hirai and colleagues wrote. “However, more recent plateaus in heavily affected New England states (Maine, Massachusetts and Vermont) may suggest some progress in addressing MOD and NAS.”

The study did not examine causes for the state-level increases in NAS and MOD, according to the researchers.