Leveraging Existing Birth Defects Surveillance Infrastructure to Build Neonatal Abstinence Syndrome Surveillance Systems - Illinois, New Mexico, and Vermont, 2015-2016

Length of Stay Among Infants with Neonatal Abstinence Syndrome and Risk of Hospital Readmission

OBJECTIVES

To assess whether a shorter length of stay (LOS) is associated with a higher risk of readmission among newborns with neonatal abstinence syndrome (NAS) and examine the risk, causes, and characteristics associated with readmissions among newborns with NAS, using a longitudinally linked population-based database.

METHODS

Our study sample included full-term singletons with NAS (n = 4,547) and without NAS (n = 327,836), born in Massachusetts during 2011-2017. We used log-binomial regression models to estimate the crude risk ratios (cRRs) and adjusted RRs with 95% confidence intervals (CI) of the association between LOS and readmissions, controlling for maternal age, race/ethnicity, education, marital status, insurance, method of delivery, birthweight, adequacy of prenatal care, smoking, and abnormal conditions of newborn.

RESULTS

Compared with infants without NAS, infants with NAS had a non-significantly higher risk of readmission within 2-42 days (2.8% vs. 2.5%; p = 0.17) and a significantly higher risk of readmission within 43-182 days (2.7% vs. 1.8%; p < 0.001). The risk of readmission within 2-42 days was significantly higher among infants with NAS with a LOS of 0-6 days compared to a LOS of 14-20 days (reference group) (aRR: 2.1; 95% CI: 1.2-3.5). No significant differences in readmission rates between 43 and 182 days were observed across LOS categories.

CONCLUSIONS

Among infants with NAS, a LOS of 0-6 days was associated with a significantly higher risk of readmission within 2-42 days of discharge compared to a longer LOS.

Misclassification of Neonatal Abstinence Syndrome Surveillance Estimates: Is Considering the Positive Predictive Value Enough?

BACKGROUND

Validation studies estimating the positive predictive value (PPV) of neonatal abstinence syndrome (NAS) have consistently suggested overreporting in hospital discharge records. However, few studies estimate the negative predictive value (NPV). Even slightly imperfect NPVs have the potential to bias estimated prevalences of rare outcomes like NAS. Given the challenges in estimating NPV, our objective was to evaluate whether the PPV was sufficient to understand the influence of NAS misclassification bias on conclusions of the NAS prevalence in surveillance research.

METHODS

We used hospital discharge data from the 2016 New Jersey State Inpatient Databases, Healthcare Cost and Utilization Project. We adjusted surveillance data for misclassification using quantitative bias analysis models to estimate the expected NAS prevalence under a range of PPV and NPV bias scenarios.

RESULTS

The 2016 observed NAS prevalence was 0.61%. The misclassification-adjusted prevalence estimates ranged from 0.31% to 0.91%. When PPV was assumed to be ≥90%, the misclassification-adjusted prevalence was typically greater than the observed prevalence but the reverse was true for PPV ≤70%. Under PPV 80%, the misclassification-adjusted prevalence was less than the observed prevalence for NPV >99.9% but flipped for NPV <99.9%.

CONCLUSIONS

When we varied the NPV below 100%, our results suggested that the direction of bias (over or underestimation) was dependent on the PPV, and sometimes dependent on the NPV. However, NPV was important for understanding the magnitude of bias. This study serves as an example of how quantitative bias analysis methods can be applied in NAS surveillance to supplement existing validation data when NPV estimates are unavailable.

Post-discharge healthcare utilization in infants with neonatal opioid withdrawal syndrome

The opioid epidemic in the United States has led to a significant increase in the incidence of neonatal opioid withdrawal syndrome (NOWS); however, the understanding of long-term consequences of NOWS is limited. The objective of this study was to evaluate post-discharge healthcare utilization in infants with NOWS and examine the association between NOWS severity and healthcare utilization. A retrospective cohort design was used to ascertain healthcare utilization in the first year after birth-related discharge using the CERNER Health Facts® database. ICD-9/ICD-10 diagnostic codes were used to identify live births and to classify infants into two study groups: NOWS and uncomplicated births (a 25% random sample). Evaluated outcomes included rehospitalization, emergency department (ED) visits within 30-days and one-year after discharge, and a composite one-year utilization event (either hospitalization or emergency department visit during that year). NOWS severity was operationalized as pharmacologic treatment, length of hospitalization, and medical conditions often associated with NOWS. In 3,526 infants with NOWS (restricted to gestational age ≥ 33 weeks), NOWS severity was associated with an increase in composite one-year utilization (OR: 1.1; 95% CI: 1.04-1.2) after adjusting for prematurity, sepsis, jaundice, use of antibiotics, infant sex, insurance status, race, hospital bed size, year of birth, and census division. In a subset of full-term infants (3008 with NOWS and 88,452 uncomplicated births), having a NOWS diagnosis was associated with higher odds of a 30-day (OR: 1.6; 95% CI: 1.03-2.4) and one-year rehospitalization (OR: 1.6; 95% CI: 1.1-2.4) after adjusting for infant sex, race, type of medical insurance, hospital location, census division, year of primary encounter, hospital bed size, and medical conditions. This study found higher healthcare utilization during the first year of life in infants diagnosed with NOWS, especially those with severe NOWS. Findings suggest a need for closer post-discharge follow-up and management of infants with NOWS.

Healthcare Patterns of Pregnant Women and Children Affected by OUD in 9 State Medicaid Populations

OBJECTIVES

State Medicaid programs are the largest single provider of healthcare for pregnant persons with opioid use disorder (OUD). Our objective was to provide comparable, multistate measures estimating the burden of OUD in pregnancy, medication for OUD (MOUD) in pregnancy, and related neonatal and child outcomes.

METHODS

Drawing on the Medicaid Outcomes Distributed Research Network (MODRN), we accessed administrative healthcare data for 1.6 million pregnancies and 1.3 million live births in 9 state Medicaid populations from 2014 to 2017. We analyzed within- and between-state prevalences and time trends in the following outcomes: diagnosis of OUD in pregnancy, initiation, and continuity of MOUD in pregnancy, Neonatal Opioid Withdrawal Syndrome (NOWS), and well-child visit utilization among children with NOWS.

RESULTS

OUD diagnosis increased from 49.6 per 1000 to 54.1 per 1000 pregnancies, and the percentage of those with any MOUD in pregnancy increased from 53.4% to 57.9%, during our study time period. State-specific percentages of 180-day continuity of MOUD ranged from 41.2% to 84.5%. The rate of neonates diagnosed with NOWS increased from 32.7 to 37.0 per 1000 live births. State-specific percentages of children diagnosed with NOWS who had the recommended well-child visits in the first 15 months ranged from 39.3% to 62.5%.

CONCLUSIONS

Medicaid data, which allow for longitudinal surveillance of care across different settings, can be used to monitor OUD and related pregnancy and child health outcomes. Findings highlight the need for public health efforts to improve care for pregnant persons and children affected by OUD.

Predictive value of indicators for identifying child maltreatment and intimate partner violence in coded electronic health records: a systematic review and meta-analysis

OBJECTIVE

Electronic health records (EHRs) are routinely used to identify family violence, yet reliable evidence of their validity remains limited. We conducted a systematic review and meta-analysis to evaluate the positive predictive values (PPVs) of coded indicators in EHRs for identifying intimate partner violence (IPV) and child maltreatment (CM), including prenatal neglect.

METHODS

We searched 18 electronic databases between January 1980 and May 2020 for studies comparing any coded indicator of IPV or CM including prenatal neglect defined as neonatal abstinence syndrome (NAS) or fetal alcohol syndrome (FAS), against an independent reference standard. We pooled PPVs for each indicator using random effects meta-analyses.

RESULTS

We included 88 studies (3 875 183 individuals) involving 15 indicators for identifying CM in the prenatal period and childhood (0-18 years) and five indicators for IPV among women of reproductive age (12-50 years). Based on the International Classification of Disease system, the pooled PPV was over 80% for NAS (16 studies) but lower for FAS (<40%; seven studies). For young children, primary diagnoses of CM, specific injury presentations (eg, rib fractures and retinal haemorrhages) and assaults showed a high PPV for CM (pooled PPVs: 55.9%-87.8%). Indicators of IPV in women had a high PPV, with primary diagnoses correctly identifying IPV in >85% of cases.

CONCLUSIONS

Coded indicators in EHRs have a high likelihood of correctly classifying types of CM and IPV across the life course, providing a useful tool for assessment, support and monitoring of high-risk groups in health services and research.

The interaction of neonatal abstinence syndrome and opioid use disorder treatment availability for women insured by medicaid

OBJECTIVE

This paper will discuss the process of mapping opioid use disorder (OUD) treatment resources for pregnant women and discuss the intersection between treatment resources and rates of neonatal abstinence syndrome (NAS).

DESIGN

A resource manual was developed through a systematic process with stakeholders across Illinois. Resources were mapped by county and overlaid with county rates of NAS, using hospital discharge data.

RESULTS

Across Illinois, 89 treatment resources were identified for pregnant women insured by Medicaid. Resources were concentrated in 36% of Illinois' counties. Counties with limited treatment resources generally had high rates of NAS. Sixty-six percent of NAS cases among rural Illinois residents had no OUD treatment resources in their county. Rural counties had less access to medication-assisted treatment (MAT), the standard of care for treatment of OUD, compared with other counties across the state.

CONCLUSIONS

Efforts to increase OUD treatment options for pregnant women insured by Medicaid should concentrate on geographic areas with limited access and high need.

Prevalence of birth defects among infants with neonatal abstinence syndrome in Illinois, 2015-2016

BACKGROUND

Opioid use has reached historically high levels across the United States and infants exposed during pregnancy are at risk of developing a drug withdrawal syndrome called neonatal abstinence syndrome (NAS). The prevalence of birth defects among Illinois infants exhibiting NAS has not been estimated.

METHODS

We linked birth certificate data for Illinois-resident infants born in Illinois in 2015 or 2016 to previously collected NAS and Adverse Pregnancy Outcome Reporting System birth defect data. We examined the prevalence of selected specific birth defects and of newborn infants with one or more of the National Birth Defects Prevention Network's (NBDPN) birth defects, comparing infants with and without NAS. We used logistic regression to estimate the odds ratio for having one or more NBDPN birth defects in infants with and without NAS, after adjusting for other risk factors.

RESULTS

Of 302,043 Illinois-resident births, 899 (3.0/1,000 live births) had NAS, and 4,250 (140.7/10,000 live births) had one or more NBDPN birth defect. Infants with an NBDPN birth defect were 1.9 (95% CI [1.3, 2.9]) times more likely to have developed NAS at delivery, and specifically, there was a higher prevalence of ventricular septal defect, club foot, and oral cleft, among infants with NAS when compared to those born without.

CONCLUSIONS

Elevated prevalence rates and odds ratios add to the growing evidence of an association between NAS and birth defects. Other studies have found similar associations between opioid exposure and the birth defects identified in this analysis.

Diagnosis Codes and Case Definitions for Neonatal Abstinence Syndrome

BACKGROUND AND OBJECTIVES

The increase in neonatal abstinence syndrome (NAS) has underscored the need for NAS surveillance programs, but many rely on passive surveillance using unverified diagnosis codes. Few studies have evaluated the validity of these codes, and no study has assessed the recently proposed Council of State and Territorial Epidemiologists (CSTE) case definition. The Florida Birth Defects Registry investigated the accuracy of International Classification of Diseases, 10th Revision, Clinical Modification codes related to NAS (P96.1 and P04.49) and assessed the sensitivity of the CSTE case definition.

METHODS

We identified a sample of infants born during 2016 coded with P96.1 and/or P04.49. Record review was completed for 128 cases coded with P96.1, 68 with P04.49, and 7 with both codes. Lacking consensus regarding a gold standard definition of NAS, we used clinical data to classify each case using the Florida and CSTE definitions. The code-specific accuracy was measured by using the positive predictive value (PPV). The clinical characteristics indicative of NAS were compared for case classification based on both definitions.

RESULTS

By using the Florida definition, the overall PPV was 68% but varied by code: 95.3% for P96.1 and 13.2% for P04.49. The overall (47.8%) and code-specific PPVs were lower by using the CSTE definition. Comparison of clinical characteristics demonstrated that 60.7% of cases classified as no NAS by using the CSTE definition had robust clinical signs of NAS. In our sample, the CSTE case definition underestimated NAS prevalence.

CONCLUSIONS

Only the P96.1 International Classification of Diseases, 10th Revision, Clinical Modification code displayed high accuracy. Discordance in NAS case definitions and surveillance methodologies may result in erroneous comparisons and conclusions that negatively impact NAS-related surveillance and research.

Surveillance, Epidemiology, and Estimated Burden of Neonatal Abstinence Syndrome, Tennessee, 2013-2016

OBJECTIVES

Between 2003 and 2013, the rate of neonatal abstinence syndrome (NAS)-a postnatal drug withdrawal syndrome-in Tennessee increased approximately 10-fold. NAS surveillance is relatively new, and underestimation associated with surveillance has not been described. We compared data from the Tennessee NAS public health surveillance system (TNSS) with a second source of NAS data, hospital discharge data system (HDDS), and estimated the true number of infants with NAS using capture-recapture methods.

METHODS

We obtained NAS data on cases of NAS among Tennessee infants from TNSS and HDDS from January 1, 2013, through December 31, 2016. We matched cases of NAS identified in TNSS to cases identified in HDDS. We estimated the true number of infants with NAS by using the Lincoln-Peterson estimator capture-recapture methodology.

RESULTS

During the study period, 4070 infants with NAS were reported to TNSS, and 5321 infants with NAS were identified in HDDS; 2757 were in both data sets. Using capture-recapture methods, the total estimated number of infants with NAS during the study period was 7855 (annual mean = 1972; estimated range = 1531-2427), which was 93% more than in TNSS and 48% more than in HDDS. Drugs used for the medication-assisted treatment of substance use disorder were the most commonly reported substances associated with NAS (n = 2389, 59%).

CONCLUSIONS

TNSS underestimated the total burden of NAS based on the capture-recapture estimate. Case-based public health surveillance is important for monitoring the burden of and risk factors for NAS and helping guide public health interventions.