Predictors of Length of Stay and Cost of Hospitalization of Neonatal Abstinence Syndrome in the United States

Background The incidence rate and economic burden of neonatal abstinence syndrome (NAS) are increasing in the United States (US). We explored the link between the length of stay (LOS) and hospitalization cost for neonatal abstinence syndrome in 2018. Methods This was a cross-sectional analysis of the 2018 national inpatient sample database. Newborn hospitalizations with neonatal abstinence syndrome and their accompanying comorbid conditions were identified using the International Classification of Diseases, 10th Edition diagnostic codes. Logistic regression was used to determine the impact of length of stay and the co-morbidities on inflation-adjusted hospital costs. Results The incidence of neonatal abstinence syndrome was 7.1 per 1000 births (95% CI 6.8-7.3) in 2018. The majority had Medicaid (84.1%), with a neonatal abstinence syndrome incidence of 13.2 (95% CI: 12.8-13.6). In adjusted analysis, every one-day increase in length of stay increased the hospital cost by $1,685 (95% CI: 1,639-1,731). Neonatal abstinence syndrome hospitalizations with Medicaid had a longer length of stay by 1.8 days (95% CI: 0.5-3.1). Co-morbidities further increased the length of stay: seizures: 13.8 days; sepsis: 4.1 days; respiratory complications: 4.4 days; and feeding problems: 5.8 days. Those at urban teaching hospitals had a longer length of stay by 7.3 days (95% CI: 5.8-8.8). Co-morbidities increased hospital cost as follows: seizures: $71,380; sepsis: $12,837; respiratory complications: $8,268; feeding problems: $7,737. The cost of hospitalization at large bed-size hospitals and urban teaching was higher by $5,243 and $12,005, respectively. Conclusion The incidence rate of neonatal abstinence syndrome remained high and was resource-intensive in 2018. Co-morbid conditions and hospitalization at urban teaching hospitals were major contributors to increased length of stay and hospital costs.