Assessment of risk factors for Neonatal Abstinence Syndrome (NAS) using a Standardized Surveillance Case Definition in Clark County, NV


  • Rachel Bryant Southern Nevada Health District
  • Brandon Delise Southern Nevada Health District
  • Ying Zhang Southern Nevada Health District
  • Niema Beckford Southern Nevada Health District
  • Cassius Lockett Southern Nevada Health District



Background: Neonatal Abstinence Syndrome (NAS) is a withdrawal syndrome in neonates that can occur due to drug exposure during pregnancy. This study had two objectives: (1) Assess the implementation of the Council of State and Territorial Epidemiologists (CSTE) Tier 2 case definition for NAS surveillance in Clark County, Nevada and (2) Identify risk factors for NAS.

Subjects and Method: This study utilized hospital discharge data. Claim-based records from non-federal acute care hospitals located in Clark County during 2016-2022 were analyzed.  All newborn inpatient discharge records from January 1, 2016 to September 30, 2022 in Clark County, Nevada were selected.  ICD-10-CM codes were utilized based on the CSTE Tier 2 case definition. Any neonate record that met the case definition, including any record with the diagnosis code P96.1, was considered a NAS confirmed case. Codes for suspect cases, maternal history of substance use, unspecified maternal medication, and transmitted noxious-substances were also assessed. A multiple logistic regression model using backward stepwise selection was developed to find risk factors related to NAS-confirmed births.

Results: In Clark County, Nevada, the NAS incidence rate from January 2016 to September 2022 was 7.4 per 1,000 births. In 2022 alone, the rate of NAS was 8.9 per 1,000 births. Estimated rates of NAS were highest among neonates who were White at 13 per 1,000 births. Hospital J, the largest academic medical center in Southern Nevada, had the highest NAS confirmed case rate at 11.3 per 1000 newborn hospitalizations. Results from the multiple logistic regression model showed the odds of being born with NAS among neonates who identified as White were 5.0 (OR=5.17; 95% CI= 4.29 to 6.24; p <0.001) times more likely to have NAS compared to the Hispanic group.

Conclusion: Given that 2022 had the highest rate of confirmed NAS cases there is a need to collect substance and diagnosis-specific data about prenatal substance use to identify unmet service care and disparities.


neonatal abstinence syndrome, opioids, substance dependence

Author Biographies

Rachel Bryant, Southern Nevada Health District

Rachel Bryant is a Council of State and Territorial Epidemiology (CSTE) Applied Fellow placed at the Southern Nevada Health District (SNHD) where she has partaken in projects relating to substance use and injury within the Epidemiology Department. Her current projects focus on surveillance of Neonatal Abstinence Syndrome and the Public Health Vending Machine evaluations. Prior to working as a CSTE Fellow, she received her MPH in Epidemiology from the University of Iowa and a Bachelor of Science in Biology from Creighton University.

Brandon Delise, Southern Nevada Health District

Mr. Delise is a Sr. Epidemiologist at SNHD where he leads efforts to monitor, develop, and improve surveillance within the fields of drug overdose and Emergency Management Services. Prior to working as an Epidemiologist, Brandon was a Disease Investigation & Intervention Specialist at the Southern Nevada Health District, an HIV Specialist at Community Health of South Florida, and an HIV/HCV Specialist at Perception Programs.Brandon received his MPH in Epidemiology from the University of Edinburgh. Brandon’s research interests include injury, trauma, and opioid use. 

Ying Zhang, Southern Nevada Health District

Dr. Ying Zhang will lend her expertise to provide assistance to the epidemiologists and DDCS as well as project oversight. Dr. Zhang is a Sr. Scientist with SNHD with expertise in the areas of community health assessment, injury and drug overdose epidemiology and surveillance, as well as application of qualitative and quantitative methods in applied epidemiology. She received her PhD in health education and minor in Statistics from the University of Nebraska – Lincoln, MPH in epidemiology from Johns Hopkins Bloomberg School of Public Health. Before joining SNHD, she worked as an injury epidemiologist at Nebraska Department of Health and Human Services (NE DHHS) from 2006 to 2013 andplayed a vital role in founding the public health data warehouse in NE DHHS. Dr. Zhang has also served as the Co-chair of the Injury Epidemiology and Surveillance Subcommittee at the Council of State and Territorial Epidemiologists (CSTE) from December 2018 to January 2023 and co-authored CSTE’s position statement in non-fatal opioid overdose standardized case definition.

Niema Beckford, Southern Nevada Health District

Niema Beckford is currently a Disease Data Collection Specialist at the Southern Nevada Health District where she assists in investigating reportable diseases by completing chart reviews, analysis, and collaborations with out-of-state public health officials. Prior to working at SNHD, Niema worked in the non-profit sector, completed various internships, and simultaneously managed her undergraduate course load at the University of Nevada, Las Vegas.

Cassius Lockett, Southern Nevada Health District

Dr. Lockett was hired as the Director of Disease Surveillance & Control with the Southern Nevada Health District in May of 2021. Prior to serving in this role he served as the Public Health Director for San Mateo County since February of 2016. Before that, he served as the Director of Community Health with the Southern Nevada Health District. From 1999 to 2001 Dr. Lockett was an epidemic intelligence officer (EIS) for the Centers for Disease Control and Prevention working for the Michigan Department of Community Health. For nearly a decade Dr. Lockett taught Epidemiology, Health Informatics, Public Health Informatics, Infectious Disease Epidemiology and Community Health at Walden University. Dr. Lockett received his undergraduate and graduate school training in nutritional epidemiology and dietetics at the University of California, Davis.


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How to Cite

Bryant, R., Delise, B., Zhang, Y., Beckford, N., & Lockett, C. (2024). Assessment of risk factors for Neonatal Abstinence Syndrome (NAS) using a Standardized Surveillance Case Definition in Clark County, NV. Journal of Maternal and Child Health, 9(1), 78–88.