Low-Level Respirable Crystalline Silica and Silicosis: Long-Term Follow-Up of Vermont Granite Workers.

The lifetime risk of silicosis associated with low-level occupational exposure to respirable crystalline silica remains unclear because most previous radiographic studies included workers with varying exposure concentrations and durations. This study assessed the prevalence of silicosis after lengthy exposure to respirable crystalline silica at levels ≤ 0.10 mg/m3. Vermont granite workers employed any time during 1979-1987 were traced and chest radiographs were obtained for 356 who were alive in 2017 and residing in Vermont. Work history, smoking habits and respiratory symptoms were obtained by interview, and exposure was estimated using a previously developed job-exposure matrix. Associations between radiographic findings, exposure, and respiratory symptoms were assessed by ANOVA, chi-square tests and binary regression. Fourteen workers (3.9%) had radiographic evidence of silicosis, and all had been employed ≥30 years. They were more likely to have been stone cutters or carvers and their average exposure concentrations and cumulative exposures to respirable crystalline silica were significantly higher than workers with similar durations of employment and no classifiable parenchymal abnormalities. This provides direct evidence that workers with long-term exposure to low-level respirable crystalline silica (≤0.10 mg/m3) are at risk of developing silicosis.

Substance use patterns, sociodemographics, and health profiles of harm reduction service recipients in Burlington, Vermont.

BACKGROUND: Understanding current substance use practices is critical to reduce and prevent overdose deaths among individuals at increased risk including persons who use and inject drugs. Because individuals participating in harm reduction and syringe service programs are actively using drugs and vary in treatment participation, information on their current drug use and preferred drugs provides a unique window into the drug use ecology of communities that can inform future intervention services and treatment provision. METHODS: Between March and June 2023, 150 participants in a harm reduction program in Burlington, Vermont completed a survey examining sociodemographics; treatment and medication for opioid use disorder (MOUD) status; substance use; injection information; overdose information; and mental health, medical, and health information. Descriptive analyses assessed overall findings. Comparisons between primary drug subgroups (stimulants, opioids, stimulants-opioids) of past-three-month drug use and treatment participation were analyzed using chi-square and Fisher's exact test. RESULTS: Most participants reported being unhoused or unstable housing (80.7%) and unemployed (64.0%) or on disability (21.3%). The drug with the greatest proportion of participants reporting past three-month use was crack cocaine (83.3%). Fentanyl use was reported by 69.3% of participants and xylazine by 38.0% of participants. High rates of stimulant use were reported across all participants independent of whether stimulants were a participant's primary drug. Fentanyl, heroin, and xylazine use was less common in the stimulants subgroup compared to opioid-containing subgroups (p < .001). Current- and past-year MOUD treatment was reported by 58.0% and 77.3% of participants. Emergency rooms were the most common past-year medical treatment location (48.7%; M = 2.72 visits). CONCLUSIONS: Findings indicate high rates of polysubstance use and the underrecognized effects of stimulant use among people who use drugs-including its notable and increasing role in drug-overdose deaths. Crack cocaine was the most used stimulant, a geographical difference from much of the US where methamphetamine is most common. With the increasing prevalence of fentanyl-adulterated stimulants and differences in opioid use observed between subgroups, these findings highlight the importance and necessity of harm reduction interventions (e.g., drug checking services, fentanyl test strips) and effective treatment for individuals using stimulants alongside MOUD treatment.

Using Insurance Claims Data to Estimate Blastomycosis Incidence, Vermont, USA, 2011-2020.

The epidemiology of blastomycosis in Vermont, USA, is poorly understood. Using insurance claims data, we estimated the mean annual blastomycosis incidence was 1.8 patients/100,000 persons during 2011-2020. Incidence and disease severity were highest in north-central counties. Our findings highlight a need for improved clinical awareness and expanded surveillance.

An ethnographic study of a community dentistry network serving Latine migrant farmworkers in Vermont: Barriers and access to care during the COVID-19 pandemic and beyond.

BACKGROUND AND OBJECTIVES: Primary dental healthcare services are not accessible for a majority of Latino/a/e migrant farmworkers in the United States. Unmet dental health needs are well documented in larger states like California, Florida and New York, but the dental healthcare picture in smaller states is not well understood. The goal of this qualitative ethnographic study was to understand the delivery model of a free dentistry network serving Latine farmworkers in rural Vermont and specific barriers experienced at the network during the COVID-19 pandemic. METHODS: Semi-structured ethnographic interviews were carried out with clinicians and transcripts were analysed using the constant comparison method to identify salient concerns and recommendations about barriers and delivery of care. RESULTS: Clinicians highlighted structural issues including farmworkers' lack of time off work and absence of transportation to attend appointments, concerns about COVID-19 safety, concerns about immigration surveillance and language barriers. Providers outlined steps for improved service delivery including mobile care at local farms, enhanced intercultural training for providers, recognizing dentistry as essential healthcare at the state level and the leverage of existing appointments for preventive health. Drawing on anthropological frameworks of place-based care and deservingness of healthcare, our ethnographic findings emphasize the role of community dentistry in bridging gaps in migrant healthcare during and beyond the COVID-19 pandemic.

Oral Rabies Vaccination of Raccoons (Procyon lotor) across a Development Intensity Gradient in Burlington, Vermont, USA, 2015-2017.

Management of the raccoon rabies virus variant in North America is conducted primarily using oral rabies vaccination (ORV). When a sufficient proportion of the population is vaccinated (∼60%), rabies transmission can be eliminated. To date, ORV programs have successfully controlled and eliminated raccoon rabies in rural areas, but there has been less success in urban areas. We studied the proportions of rabies virus neutralizing antibodies (RVNA) in a raccoon (Procyon lotor) population during a 3-yr ORV trial in developed areas of Burlington, Vermont, US. We used a modified N-mixture model to estimate raccoon abundance, RVNA seroprevalence, and capture rates jointly to examine factors that relate to ORV success to better inform management. We found that raccoon abundance was lower in less-developed areas compared to urban centers. Raccoon RVNA seroprevalence decreased as population abundance increased; it increased as the average age of the population increased. Nontarget opossum (Didelphis virginiana) captures correlated with a decrease in raccoon RVNA seroprevalence in low-development areas, suggesting that they may be competing for baits. The target bait density across the entire study area was 150 baits/km2, but a hand baiting strategy was heavily concentrated on roads, resulting in uneven bait densities within sampling sites (0-484 baits/km2). Uneven bait distribution across the study area may explain low RVNA seroprevalence in some locations. Our results suggest that increases in bait density across the study area may improve RVNA seroprevalence and support annual ORV to account for raccoon population turnover.

Surveillance of Vermont wildlife in 2021-2022 reveals no detected SARS-CoV-2 viral RNA.

Previous studies have documented natural infections of SARS-CoV-2 in various domestic and wild animals. More recently, studies have been published noting the susceptibility of members of the Cervidae family, and infections in both wild and captive cervid populations. In this study, we investigated the presence of SARS-CoV-2 in mammalian wildlife within the state of Vermont. 739 nasal or throat samples were collected from wildlife throughout the state during the 2021 and 2022 harvest season. Data was collected from red and gray foxes (Vulpes vulples and Urocyon cineroargentus, respectively), fishers (Martes pennati), river otters (Lutra canadensis), coyotes (Canis lantrans), bobcats (Lynx rufus rufus), black bears (Ursus americanus), and white-tailed deer (Odocoileus virginianus). Samples were tested for the presence of SARS-CoV-2 via quantitative RT-qPCR using the CDC N1/N2 primer set and/or the WHO-E gene primer set. Surprisingly, we initially detected a number of N1 and/or N2 positive samples with high cycle threshold values, though after conducting environmental swabbing of the laboratory and verifying with a second independent primer set (WHO-E) and PCR without reverse transcriptase, we showed that these were false positives due to plasmid contamination from a construct expressing the N gene in the general laboratory environment. Our final results indicate that no sampled wildlife were positive for SARS-CoV-2 RNA, and highlight the importance of physically separate locations for the processing of samples for surveillance and experiments that require the use of plasmid DNA containing the target RNA sequence. These negative findings are surprising, given that most published North America studies have found SARS-CoV-2 within their deer populations. The absence of SARS-CoV-2 RNA in populations sampled here may provide insights in to the various environmental and anthropogenic factors that reduce spillover and spread in North American's wildlife populations.

A Survey of Cancer Risk Behaviors, Beliefs, and Social Drivers of Health in New Hampshire and Vermont.

Compared with urban areas, rural areas have higher cancer mortality and have experienced substantially smaller declines in cancer incidence in recent years. In a New Hampshire (NH) and Vermont (VT) survey, we explored the roles of rurality and educational attainment on cancer risk behaviors, beliefs, and other social drivers of health. In February-March 2022, two survey panels in NH and VT were sent an online questionnaire. Responses were analyzed by rurality and educational attainment. Respondents (N = 1,717, 22%) mostly lived in rural areas (55%); 45% of rural and 25% of urban residents had high school education or less and this difference was statistically significant. After adjustment for rurality, lower educational attainment was associated with smoking, difficulty paying for basic necessities, greater financial difficulty during the COVID-19 pandemic, struggling to pay for gas (P < 0.01), fatalistic attitudes toward cancer prevention, and susceptibility to information overload about cancer prevention. Among the 33% of respondents who delayed getting medical care in the past year, this was more often due to lack of transportation in those with lower educational attainment (21% vs. 3%, P = 0.02 adjusted for rurality) and more often due to concerns about catching COVID-19 among urban than rural residents (52% vs. 21%; P < 0.001 adjusted for education). In conclusion, in NH/VT, smoking, financial hardship, and beliefs about cancer prevention are independently associated with lower educational attainment but not rural residence. These findings have implications for the design of interventions to address cancer risk in rural areas. Significance: In NH and VT, the finding that some associations between cancer risk factors and rural residence are more closely tied to educational attainment than rurality suggest that the design of interventions to address cancer risk should take educational attainment into account.

Attitudes and beliefs about Vermont's 2021 buprenorphine decriminalization law among residents who use illicit opioids.

BACKGROUND: In July 2021, Vermont removed all criminal penalties for possessing 224mg or less of buprenorphine. METHODS: Vermont residents (N=474) who used illicit opioid drugs or received treatment for opioid use disorder in the past 90 days were recruited for a mixed-methods survey on the health and criminal legal effects of decriminalization. Topics assessed included: motivations for using non-prescribed buprenorphine, awareness of and support for decriminalization, and criminal legal system experiences involving buprenorphine. We examined the frequencies of quantitative measures and qualitatively summarized themes from free-response questions. RESULTS: Three-quarters of respondents (76%) reported lifetime use of non-prescribed buprenorphine. 80% supported decriminalization, but only 28% were aware buprenorphine was decriminalized in Vermont. Respondents described using non-prescribed buprenorphine to alleviate withdrawal symptoms and avoid use of other illicit drugs. 18% had been arrested while in buprenorphine, with non-White respondents significantly more likely to report such arrests (15% v 33%, p<0.001). CONCLUSION: Decriminalization of buprenorphine may reduce unnecessary criminal legal system involvement, but its health impact was limited by low awareness at the time of our study.

Statewide Assessment of the Hepatitis C Virus Care Cascade for Incarcerated Persons in Vermont.

OBJECTIVES: Incarcerated persons in the United States have a high burden of hepatitis C virus (HCV) infection. This study assessed the impact of a statewide effort in Vermont to treat HCV in this group. METHODS: We performed a retrospective, observational cohort study of all HCV-infected persons who were imprisoned in Vermont during the 19-month study period (December 2018-June 2020). The cascade of care comprised opt-out HCV screening, full access to direct-acting antiviral treatment (without hepatic fibrosis-based treatment restrictions), HCV specialist involvement, and medication-assisted treatment for patients with opioid use disorder. The primary outcome was sustained virologic response at 12 weeks after treatment completion (SVR12). RESULTS: The study included 217 HCV-infected patients; the median age was 35 years (range, 18-73 years), 89% were male, 76% had opioid use disorder, 67% had a psychiatric comorbidity, and 9% had cirrhosis. Of the 217 patients, 98% had a liver fibrosis assessment, 59% started direct-acting antiviral treatment, 55% completed direct-acting antiviral treatment, and 51% achieved documented SVR12. Of the 129 HCV-infected persons who started direct-acting antiviral treatment, 92% completed therapy and 86% achieved documented SVR12. Psychiatric comorbidity was not significantly associated with achieving SVR12 (odds ratio = 0.67; 95% CI, 0.27-1.65; P = .38), nor was receiving medication-assisted treatment for patients with opioid use disorder (odds ratio = 1.45; 95% CI, 0.62-2.56; P = .45). CONCLUSIONS: This study reports the highest SVR12 rate achieved in a state incarcerated population to date. HCV treatment in incarcerated populations is a practical and efficacious strategy that should serve a foundational role in HCV elimination.

Lessons learned from linking two complementary databases: the Society of Thoracic Surgeons Congenital Heart Surgery Database and The Vermont Oxford Network Expanded Database.

The Society of Thoracic Surgeons Congenital Heart Surgery Database and the Vermont Oxford Network Expanded Database are both large, international, well-established quality and outcomes databases with high penetration in their respective fields of congenital heart surgery and neonatology. Previous studies have shown the value of combining large databases for research purposes. Our aim was to examine the feasibility and value of combining these databases on a local level.We included patients from both databases, cared for at our centre and born from 2015-2020, who had cardiac surgery as neonates or during the birth hospitalisation. We examined the number of patients from each database and overlap between the two. We compared cardiac diagnoses, surgeries performed, pre-operative factors, mortality, and length of stay between databases.Of the 255 patients meeting criteria, 209 (81.9%) had records in both databases. The most common diagnoses in both were hypoplastic left heart syndrome, coarctation, and transposition of the great arteries. Surgical data were incompletely recorded in Vermont Oxford. Gestational age, birth weight, multiple gestation, mortality, and length of stay did not differ significantly between the databases, while the percentage of patients with an extracardiac malformation or genetic syndrome recorded was higher in the Society for Thoracic Surgeons group.Larger-scale matching and comparison studies using these databases are feasible and desirable; for some variables, a record with data from both databases may be more complete. Specific attention should be given to inclusion criteria, reconciling different schema of diagnoses, and formulating questions relying on each database's relative strengths.

Food Security Impacts of the COVID-19 Pandemic: Longitudinal Evidence from a Cohort of Adults in Vermont during the First Year.

This study assessed changes in household food insecurity throughout the first year of the COVID-19 pandemic in a cohort of adults in the state of Vermont, USA, and examined the socio-demographic characteristics associated with increased odds of experiencing food insecurity during the pandemic. We conducted three online surveys between March 2020 and March 2021 to collect longitudinal data on food security, use of food assistance programs, and job disruptions during the COVID-19 pandemic. Food security was measured using the USDA six-item module. Among the 441 respondents, food insecurity rates increased significantly during the pandemic and remained above pre-pandemic levels a year after the start of the pandemic. Nearly a third (31.6%) of respondents experienced food insecurity at some point during the first year of the pandemic, with 53.1% of food-insecure households being classified as newly food-insecure. The odds of experiencing food insecurity during the pandemic varied based on socio-demographic factors. Households with children (OR 5.5, 95% CI 1.782−16.936, p < 0.01), women (OR 8.1, 95% CI 1.777−36.647, p < 0.05), BIPOC/Hispanic respondents (OR 11.8, 95% CI 1.615−85.805, p < 0.05), and households experiencing a job disruption (OR 5.0, 95% CI 1.583−16.005, p <0.01) had significantly higher odds of experiencing food insecurity during the first year of the COVID-19 pandemic, while respondents with a college degree (OR 0.08; 95% CI 0.025−0.246; p < 0.001) and household income of ≥USD 50,000 (OR 0.01; 95% CI 0.003−0.038; p < 0.001) had lower odds of experiencing food insecurity. These findings indicate that food insecurity continued to be a significant challenge one year after the start of the pandemic, which is important, given the adverse health impacts associated with food insecurity and health disparities among certain socio-demographic groups.

Correctional-Facility-Outbreak-Associated COVID-19 Cases Among Asymptomatic Persons Identified Through Universal Testing: Vermont, 2020.

On April 6, 2020, a confirmed COVID-19 case in a correctional facility employee (Staff A) was reported to the Vermont Department of Health (VDH). Staff A worked in the facility while symptomatic, without reporting symptoms, for 10 days. VDH and the facility conducted two facility-wide testing events, implemented symptom monitoring, and initiated contact tracing. All 197 incarcerated persons and 115 (71%) staff were tested for SARS-CoV-2; 45 (23%) incarcerated persons and 17 (10%) staff had positive results (confirmed case), of whom 37 (82%) incarcerated persons and 1 (6%) staff had asymptomatic infections. Case detection enabled isolation of incarcerated persons and staff, work exclusion of staff with COVID-19, and quarantine of staff and incarcerated persons who had close contact with persons with COVID-19. Broad-based SARS-CoV-2 testing identified more cases than symptom monitoring.

Survey of awareness, attitudes, and compliance with COVID-19 measures among Vermont residents.

The objective of this research was to examine residents' awareness, attitudes, and compliance with COVID-19 public health guidelines in Vermont, which emerged as an early leader in national pandemic response. Our methods included conducting an online survey of adult Vermont residents between January and April 2021. We analyzed demographics associated with awareness and compliance, and identified features associated with non-compliance. Our results show that of the 2,208 adult Vermont residents who completed the survey, 90% were extremely aware of the state's COVID-19 guidelines, and 95% reported knowing exactly what to do to follow recommended actions. Political affiliation emerged as a primary factor related to attitudes and compliance. Self-identified Republicans were less likely to agree that public health measures keep people safe or help businesses stay open, and were less likely to follow masking, quarantine, social distancing, and vaccine guidance than Independents, Progressives, and Democrats. The large differences in COVID-19 infection and death rates across the country, and recent shift toward a "pandemic of the unvaccinated," underscore the need for identifying public health strategies that work in some areas in order to adapt and apply them to areas that have struggled with controlling the virus. Consistent with national surveys, our results show that resistance to public health guidance is a partisan challenge even in states with high compliance. Identifying populations that are less supportive or hesitant to follow guidelines while understanding factors that motivate compliance can help inform strategies for developing targeted programs to encourage collective action on pandemic response. Developing communication strategies that reach people who do not believe COVID-19 guidelines keep them safe is necessary to reach universal compliance.

A 40-year Study of the Factors Associated with Diaphyseal Forearm Fractures in Skiers and Snowboarders.

BACKGROUND: Skiing and snowboarding are popular sports that are associated with a high number of orthopaedic injuries. Diaphyseal forearm fractures are an important subset of these injuries. To our knowledge, factors associated with these injuries, the mechanisms that cause them, and their relative frequencies in skiers and snowboarders have not been described. In addition, it has been proposed that the use of wrist guards may increase the risk of sustaining a diaphyseal forearm fracture; therefore, we sought to explore the relationship between wrist guard use and diaphyseal forearm fractures. QUESTIONS/PURPOSES: (1) What are the relative frequencies and types of diaphyseal forearm fractures in skiers and snowboarders? (2) What factors are associated with these injuries? (3) Is the use of wrist guards associated with an increased risk of forearm fractures? METHODS: This was an unmatched case-control study performed with an injury database from a university-run clinic at the base lodge of a major ski resort. Cases were injured skiers and snowboarders; controls were randomly selected uninjured skiers and snowboarders. Data were collected on the mechanism of injury; experience level; equipment; radiographs; skiing or snowboarding habits; and trail type, defined as green circle (easiest), blue square (intermediate), black diamond (difficult), and double black diamond (most difficult). From this database, we identified 84 patients with diaphyseal forearm fractures, one of which was a Monteggia fracture and was excluded. A logistic regression analysis was used to compare the injured and control groups to identify factors associated with diaphyseal forearm fractures, including wrist guard use. RESULTS: When adjusted for participant days, diaphyseal forearm fractures were more common in snowboarders than skiers (0.03 injuries per 1000 person-days versus 0.004 per 1000 person-days). On multivariable analysis, factors associated with forearm fractures in skiers were younger age (odds ratio 1.08 [95% CI 1.05 to 1.14]; p < 0.01), being a man or boy (OR 11.9 [95% CI 2.5 to 57.2]; p < 0.01), lack of movement at the time of falling (OR 18.2 [95% CI 3.2 to 102.5]; p < 0.01), and skiing on green circle trails compared with black diamond trails (OR 3.6 [95% CI 1.4 to 12.5]; p = 0.04). Factors associated with forearm fractures in snowboarders were younger age (OR 1.08 [95% CI 1.02 to 1.15]; p = 0.01), decreased weight (OR 1.02 [95% CI 1.00 to 1.02]; p < 0.01), snowboarding on gentle terrain (OR 8.4 [95% CI 1.6 to 45.0]; p = 0.01), and snowboarding on groomed terrain compared with other (OR 7.2 [95% CI 1.9 to 28.0]; p < 0.01) or wet, heavy snow (OR 24.8 [95% CI 2.5 to 246.7]; p = 0.01). Wrist guard use was not associated with an increased odds of diaphyseal forearm fracture in skiers or snowboarders. CONCLUSION: Diaphyseal forearm fractures occur more frequently in snowboarders than in skiers. Despite speculation in prior evidence that wrist guards may paradoxically increase the risk of sustaining these injuries, our study suggests that this is not the case and wrist guards are not unsafe to wear. LEVEL OF EVIDENCE: Level III, prognostic study.

Use of Cervid Serosurveys to Monitor Eastern Equine Encephalitis Virus Activity in Northern New England, United States, 2009-2017.

Vertebrate surveillance for eastern equine encephalitis virus (EEEV) activity usually focuses on three types of vertebrates: horses, passerine birds, and sentinel chicken flocks. However, there is a variety of wild vertebrates that are exposed to EEEV infections and can be used to track EEEV activity. In 2009, we initiated a pilot study in northern New England, United States, to evaluate the effectiveness of using wild cervids (free-ranging white-tailed deer and moose) as spatial sentinels for EEEV activity. In Maine, New Hampshire, and Vermont during 2009-2017, we collected blood samples from hunter-harvested cervids at tagging stations and obtained harvest location information from hunters. U.S. Centers for Disease Control and Prevention processed the samples for EEEV antibodies using plaque reduction neutralization tests (PRNTs). We detected EEEV antibodies in 6 to 17% of cervid samples in the different states and mapped cervid EEEV seropositivity in northern New England. EEEV antibody-positive cervids were the first detections of EEEV activity in the state of Vermont, in northern Maine, and northern New Hampshire. Our key result was the detection of the antibodies in areas far outside the extent of documented wild bird, mosquito, human case, or veterinary case reports of EEEV activity in Maine, New Hampshire, and Vermont. These findings showed that cervid (deer and moose) serosurveys can be used to characterize the geographic extent of EEEV activity, especially in areas with low EEEV activity or with little or no EEEV surveillance. Cervid EEEV serosurveys can be a useful tool for mapping EEEV activity in areas of North America in addition to northern New England.

Follow-through care for high-risk infants during the COVID-19 pandemic: lessons learned from the Vermont Oxford Network.

OBJECTIVE: The COVID-19 pandemic has altered the delivery of follow-up care for high-risk infants. We performed an audit to characterize programmatic responses in a quality improvement network. STUDY DESIGN: We audited 43 North American-based follow-up programs of the Vermont Oxford Network Extremely Low Birth Weight Follow-up Study Group in October, 2020. Our electronic survey included yes/no, agree/disagree, and free text response items. RESULT: The response rate was 67.4%. Most programs altered capacity and the timing, frequency, or content of clinical assessments. Most perceived practice changes compromised their ability to ascertain infants' medical and developmental needs. There was a rapid uptake of telemedicine services. Despite challenges with implementation, many endorsed improved connectedness with families. CONCLUSION: Programs adapted rapidly to meet the needs of high-risk infants during the pandemic. Clinical operations, assessment procedures, and quality metrics will also need to evolve. Quality improvement study group collaboratives are well-positioned to coordinate such work.

Severity of Bronchopulmonary Dysplasia Among Very Preterm Infants in the United States.

BACKGROUND AND OBJECTIVES: The Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network recently proposed new, severity-based diagnostic criteria for bronchopulmonary dysplasia (BPD). This study provides the first benchmark epidemiological data applying this definition. METHODS: Retrospective cohort study of infants born from 22 to 29 weeks' gestation in 2018 at 715 US hospitals in the Vermont Oxford Network. Rates of BPD, major neonatal morbidities, and common respiratory therapies, stratified by BPD severity, were determined. RESULTS: Among 24 896 infants, 2574 (10.3%) died before 36 weeks' postmenstrual age (PMA), 12 198 (49.0%) did not develop BPD, 9192 (36.9%) developed grade 1 or 2 BPD, and 932 (3.7%) developed grade 3 BPD. Rates of mortality before 36 weeks' PMA and grade 3 BPD decreased from 52.7% and 9.9%, respectively, among infants born at 22 weeks' gestation to 17.3% and 0.8% among infants born at 29 weeks' gestation. Grade 1 or 2 BPD peaked in incidence (51.8%) among infants born at 25 weeks' gestation. The frequency of severe intraventricular hemorrhage or cystic periventricular leukomalacia increased from 4.8% among survivors without BPD to 23.4% among survivors with grade 3 BPD. Similar ranges were observed for late onset sepsis (4.8%-31.4%), surgically treated necrotizing enterocolitis (1.4%-17.1%), severe retinopathy of prematurity (1.2%-23.0%), and home oxygen therapy (2.0%-67.5%). CONCLUSIONS: More than one-half of very preterm infants born in the United States died before 36 weeks' PMA or developed BPD. Greater BPD severity was associated with more frequent development of major neonatal morbidities, in-hospital mortality, and use of supplemental respiratory support at discharge.

Association of Recreational Cannabis Legalization With Maternal Cannabis Use in the Preconception, Prenatal, and Postpartum Periods.

Importance: Recent studies have revealed increases in population-level cannabis use after legalization of recreational cannabis. However, the association of cannabis legalization with maternal cannabis use during important life stages remains unknown. Objective: To investigate the association of legalization of recreational cannabis with maternal cannabis use during the preconception, prenatal, and postpartum periods. Design, Setting, and Participants: This repeated cross-sectional study used state-level data on women who delivered live-born infants in the US from the Pregnancy Risk Assessment Monitoring System from January 2004 to December 2018. Data from 2 states that had legalized recreational cannabis (Alaska and Maine) and 2 states that had not legalized recreational cannabis (New Hampshire and Vermont) were used. Women completed surveys 2 to 6 months after delivery, reporting preconception, prenatal, and postpartum cannabis use. Exposure: State recreational cannabis legalization. Main Outcomes and Measures: The 3 primary outcomes were self-reported cannabis use during the 12 months before pregnancy (preconception), during pregnancy (prenatal), and the 2 to 6 months after pregnancy (postpartum). A difference-in-differences analysis was used to compare changes in the prevalence of maternal cannabis use during each period before and after state legalization of recreational cannabis, controlling for maternal characteristics (age, race/ethnicity, educational level, income, cigarette smoking, and breastfeeding) and state fixed effects. State-specific survey weights were used. Results: The analytic sample included 23 082 women in the preconception period, 23 859 in the prenatal period, and 26 610 in the postpartum period. In each analysis, most women were married (range among all groups, 63.9%-64.8%), aged 25 to 34 years (preconception, 55.4%; prenatal, 55.9%; postpartum, 56.1%), and had an annual household income less than $50 000 (preconception, 55.7%; prenatal, 56.3%; postpartum, 55.5%). In adjusted analyses, preconception and postpartum cannabis use increased significantly in states that had legalized recreational cannabis compared with states that had not legalized it (preconception risk difference, 0.0457 [95% CI, 0.0013-0.0900]; P = .04; postpartum risk difference, 0.0539 [95% CI, 0.0259-0.0818]; P < .001). The risk difference for prenatal cannabis use was not significant (0.0070; 95% CI, -0.0120 to 0.0260; P = .47). Conclusions and Relevance: In this repeated cross-sectional study, recreational cannabis legalization was associated with changes in maternal cannabis use before and after pregnancy. The findings suggest that future studies should undertake an interdisciplinary approach to maximize benefit and application of findings to future public health, health care, and policy sectors.