Increasing incidence and geographic distribution of neonatal abstinence syndrome: United States 2009 to 2012

Abstract

Objective: Neonatal abstinence syndrome (NAS), a postnatal opioid withdrawal syndrome, increased threefold from 2000 to 2009. Since 2009, opioid pain reliever prescriptions and complications increased markedly throughout the United States. Understanding recent changes in NAS and its geographic variability would inform state and local governments in targeting public health responses.

Study design: We utilized diagnostic and demographic data for hospital discharges from 2009 to 2012 from the Kids' Inpatient Database and the Nationwide Inpatient Sample. NAS-associated diagnoses were identified utilizing International Classification of Diseases, Ninth Revision, Clinical Modification codes. All analyses were conducted with nationally weighted data. Expenditure data were adjusted to 2012 US dollars. Between-year differences were determined utilizing least squares regression.

Results: From 2009 to 2012, NAS incidence increased nationally from 3.4 (95% confidence interval (CI): 3.2 to 3.6) to 5.8 (95% CI 5.5 to 6.1) per 1000 hospital births, reaching a total of 21,732 infants with the diagnosis. Aggregate hospital charges for NAS increased from $732 million to $1.5 billion (P<0.001), with 81% attributed to state Medicaid programs in 2012. NAS incidence varied by geographic census division, with the highest incidence rate (per 1000 hospital births) of 16.2 (95% CI 12.4 to 18.9) in the East South Central Division (Kentucky, Tennessee, Mississippi and Alabama) and the lowest in West South Central Division Oklahoma, Texas, Arkansas and Louisiana 2.6 (95% CI 2.3 to 2.9).

Conclusion: NAS incidence and hospital charges grew substantially during our study period. This costly public health problem merits a public health approach to alleviate harm to women and children. States, particularly, in areas of the country most affected by the syndrome must continue to pursue primary prevention strategies to limit the effects of opioid pain reliever misuse.

Figure 1. Incidence of neonatal abstinence syndrome per 1,000 hospital births in the United States, 2009-2012

* Data obtained from the Kids’ Inpatient Database for 2009 and 2012 and from the Nationwide Inpatient Sample in 2010 at 2011. ** 2009: 3.4 (95%CI 3.2-3.6); 2010: 4.8 (95%CI 4.3-5.2); 2011: 5.0 (95%CI 4.4-5.4); 2012: 5.8 (95%CI 5.5-6.1)

Figure 2. Incidence of neonatal abstinence syndrome per 1,000 hospital births by US Census Bureau geographic division, 2012

Figure 2. Incidence of neonatal abstinence syndrome per 1,000 hospital births by US Census Bureau geographic division, 2012