Obstetric Complications and Birth Outcomes After Antenatal Coronavirus Disease 2019 (COVID-19) Vaccination

OBJECTIVE

To evaluate the association between antenatal messenger RNA (mRNA) coronavirus disease 2019 (COVID-19) vaccination and risk of adverse pregnancy outcomes.

METHODS

This was a retrospective cohort study of individuals with singleton pregnancies with live deliveries between June 1, 2021, and January 31, 2022, with data available from eight integrated health care systems in the Vaccine Safety Datalink. Vaccine exposure was defined as receipt of one or two mRNA COVID-19 vaccine doses (primary series) during pregnancy. Outcomes were preterm birth (PTB) before 37 weeks of gestation, small-for-gestational age (SGA) neonates, gestational diabetes mellitus (GDM), gestational hypertension, and preeclampsia-eclampsia-HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome. Outcomes in individuals vaccinated were compared with those in propensity-matched individuals with unexposed pregnancies. Adjusted hazard ratios (aHRs) and 95% CIs were estimated for PTB and SGA using a time-dependent covariate Cox model, and adjusted relative risks (aRRs) were estimated for GDM, gestational hypertension, and preeclampsia-eclampsia-HELLP syndrome using Poisson regression with robust variance.

RESULTS

Among 55,591 individuals eligible for inclusion, 23,517 (42.3%) received one or two mRNA COVID-19 vaccine doses during pregnancy. Receipt of mRNA COVID-19 vaccination varied by maternal age, race, Hispanic ethnicity, and history of COVID-19. Compared with no vaccination, mRNA COVID-19 vaccination was associated with a decreased risk of PTB (rate: 6.4 [vaccinated] vs 7.7 [unvaccinated] per 100, aHR 0.89; 95% CI, 0.83-0.94). Messenger RNA COVID-19 vaccination was not associated with SGA (8.3 vs 7.4 per 100; aHR 1.06, 95% CI, 0.99-1.13), GDM (11.9 vs 10.6 per 100; aRR 1.00, 95% CI, 0.90-1.10), gestational hypertension (10.8 vs 9.9 per 100; aRR 1.08, 95% CI, 0.96-1.22), or preeclampsia-eclampsia-HELLP syndrome (8.9 vs 8.4 per 100; aRR 1.10, 95% CI, 0.97-1.24).

CONCLUSION

Receipt of an mRNA COVID-19 vaccine during pregnancy was not associated with an increased risk of adverse pregnancy outcomes; this information will be helpful for patients and clinicians when considering COVID-19 vaccination in pregnancy.

Attitudes Toward COVID-19 Vaccines Among Pregnant and Recently Pregnant Individuals

Importance

Pregnant people and infants are at high risk of severe COVID-19 outcomes. Understanding changes in attitudes toward COVID-19 vaccines among pregnant and recently pregnant people is important for public health messaging.

Objective

To assess attitudinal trends regarding COVID-19 vaccines by (1) vaccination status and (2) race, ethnicity, and language among samples of pregnant and recently pregnant Vaccine Safety Datalink (VSD) members from 2021 to 2023.

Design, Setting, and Participants

This cross-sectional surveye study included pregnant or recently pregnant members of the VSD, a collaboration of 13 health care systems and the US Centers for Disease Control and Prevention. Unvaccinated, non-Hispanic Black, and Spanish-speaking members were oversampled. Wave 1 took place from October 2021 to February 2022, and wave 2 took place from November 2022 to February 2023. Data were analyzed from May 2022 to September 2023.

Exposures

Self-reported or electronic health record (EHR)-derived race, ethnicity, and preferred language.

Main Outcomes and Measures

Self-reported vaccination status and attitudes toward monovalent (wave 1) or bivalent Omicron booster (wave 2) COVID-19 vaccines. Sample- and response-weighted analyses assessed attitudes by vaccination status and 3 race, ethnicity, and language groupings of interest.

Results

There were 1227 respondents; all identified as female, the mean (SD) age was 31.7 (5.6) years, 356 (29.0%) identified as Black race, 555 (45.2%) identified as Hispanic ethnicity, and 445 (36.3%) preferred the Spanish language. Response rates were 43.5% for wave 1 (652 of 1500 individuals sampled) and 39.5% for wave 2 (575 of 1456 individuals sampled). Respondents were more likely than nonrespondents to be White, non-Hispanic, and vaccinated per EHR. Overall, 76.8% (95% CI, 71.5%-82.2%) reported 1 or more COVID-19 vaccinations; Spanish-speaking Hispanic respondents had the highest weighted proportion of respondents with 1 or more vaccination. Weighted estimates of somewhat or strongly agreeing that COVID-19 vaccines are safe decreased from wave 1 to 2 for respondents who reported 1 or more vaccinations (76% vs 50%; χ21 = 7.8; P < .001), non-Hispanic White respondents (72% vs 43%; χ21 = 5.4; P = .02), and Spanish-speaking Hispanic respondents (76% vs 53%; χ21 = 22.8; P = .002).

Conclusions and Relevance

Decreasing confidence in COVID-19 vaccine safety in a large, diverse pregnant and recently pregnant insured population is a public health concern.

Characterisation and validation of lactation information from structured electronic health records for use in pharmacoepidemiological studies

BACKGROUND

Breastfeeding information stored within electronic health records (EHR) has recently been used for pharmacoepidemiological research, however the data are primarily collected for clinical care.

OBJECTIVES

To characterise breastfeeding information recorded in structured fields in EHR during infant and postpartum health care visits, and to assess the validity of lactation status based on EHR data versus maternal report at research study visits.

METHODS

We assessed breastfeeding information recorded in structured fields in EHR from one health system for a subset of 211 patients who were also enrolled in a study on breast milk composition between 2014 and 2017 that required participants to exclusively breastfeed their infants until at least 1 month of age. We assessed the frequency of breastfeeding information in EHR during the first 12 months of age and compared lactation status based on EHR with maternal report at 1 and 6-month study visits (reference standard).

RESULTS

The median number of breastfeeding records in the EHR per infant was six (interquartile range 3) with most observations clustering in the first few weeks of life and around well-infant visits. At the 6-month study visit, 93.8% of participants were breastfeeding and 80.1% were exclusively breastfeeding according to maternal report. Sensitivity of EHR data for identifying ever breastfeeding was at or near 100%, and sensitivity for identifying ever exclusive breastfeeding was 98.0% (95% CI: 95.0%, 99.2%). Sensitivities were 97.3% (95% CI: 93.9%, 98.9%) for identifying any breastfeeding and 94.4% (95% CI: 89.7%, 97.0%) for exclusive breastfeeding, and positive predictive values were 99.5% (95% CI: 97.0%, 99.9%) for any breastfeeding and 95.0% (95% CI: 90.4%, 97.4%) for exclusive breastfeeding.

CONCLUSIONS

Breastfeeding information in structured EHR fields have the potential to accurately classify lactation status. The validity of these data should be assessed in populations with a lower breastfeeding prevalence.

Mortality risk after COVID-19 vaccination: A self-controlled case series study

BACKGROUND

Although previous studies found no-increased mortality risk after COVID-19 vaccination, residual confounding bias might have impacted the findings. Using a modified self-controlled case series (SCCS) design, we assessed the risk of non-COVID-19 mortality, all-cause mortality, and four cardiac-related death outcomes after primary series COVID-19 vaccination.

METHODS

We analyzed all deaths between December 14, 2020, and August 11, 2021, among individuals from eight Vaccine Safety Datalink sites. Demographic characteristics of deaths in recipients of COVID-19 vaccines and unvaccinated individuals were reported. We conducted SCCS analyses by vaccine type and death outcomes and reported relative incidences (RI). The observation period for death spanned from the dates of emergency use authorization to the end of the study period (August 11, 2021) without censoring the observation period upon death. We pre-specified a primary risk interval of 28-day and a secondary risk interval of 14-day after each vaccination dose. Adjusting for seasonality in mortality analyses is crucial because death rates vary over time. Deaths among unvaccinated individuals were included in SCCS analyses to account for seasonality by incorporating calendar month in the models.

RESULTS

For Pfizer-BioNTech (BNT162b2), RIs of non-COVID-19 mortality, all-cause mortality, and four cardiac-related death outcomes were below 1 and 95 % confidence intervals (CIs) excluded 1 across both doses and both risk intervals. For Moderna (mRNA-1273), RI point estimates of all outcomes were below 1, although the 95 % CIs of two RI estimates included 1: cardiac-related (RI = 0.78, 95 % CI, 0.58-1.04) and non-COVID-19 cardiac-related mortality (RI = 0.80, 95 % CI, 0.60-1.08) 14 days after the second dose in individuals without pre-existing cancer and heart disease. For Janssen (Ad26.COV2.S), RIs of four cardiac-related death outcomes ranged from 0.94 to 0.98 for the 14-day risk interval, and 0.68 to 0.72 for the 28-day risk interval and 95 % CIs included 1.

CONCLUSION

Using a modified SCCS design and adjusting for temporal trends, no-increased risk was found for non-COVID-19 mortality, all-cause mortality, and four cardiac-related death outcomes among recipients of the three COVID-19 vaccines used in the US.

Clinical Epidemiology and Risk Factors for Critical Outcomes Among Vaccinated and Unvaccinated Adults Hospitalized With COVID-19-VISION Network, 10 States, June 2021-March 2023

BACKGROUND

The epidemiology of coronavirus disease 2019 (COVID-19) continues to develop with emerging variants, expanding population-level immunity, and advances in clinical care. We describe changes in the clinical epidemiology of COVID-19 hospitalizations and risk factors for critical outcomes over time.

METHODS

We included adults aged ≥18 years from 10 states hospitalized with COVID-19 June 2021-March 2023. We evaluated changes in demographics, clinical characteristics, and critical outcomes (intensive care unit admission and/or death) and evaluated critical outcomes risk factors (risk ratios [RRs]), stratified by COVID-19 vaccination status.

RESULTS

A total of 60 488 COVID-19-associated hospitalizations were included in the analysis. Among those hospitalized, median age increased from 60 to 75 years, proportion vaccinated increased from 18.2% to 70.1%, and critical outcomes declined from 24.8% to 19.4% (all P < .001) between the Delta (June-December, 2021) and post-BA.4/BA.5 (September 2022-March 2023) periods. Hospitalization events with critical outcomes had a higher proportion of ≥4 categories of medical condition categories assessed (32.8%) compared to all hospitalizations (23.0%). Critical outcome risk factors were similar for unvaccinated and vaccinated populations; presence of ≥4 medical condition categories was most strongly associated with risk of critical outcomes regardless of vaccine status (unvaccinated: adjusted RR, 2.27 [95% confidence interval {CI}, 2.14-2.41]; vaccinated: adjusted RR, 1.73 [95% CI, 1.56-1.92]) across periods.

CONCLUSIONS

The proportion of adults hospitalized with COVID-19 who experienced critical outcomes decreased with time, and median patient age increased with time. Multimorbidity was most strongly associated with critical outcomes.

Impact of accounting for correlation between COVID-19 and influenza vaccination in a COVID-19 vaccine effectiveness evaluation using a test-negative design

Test-negative-design COVID-19 vaccine effectiveness (VE) studies use symptomatic SARS-CoV-2-positive individuals as cases and symptomatic SARS-CoV-2-negative individuals as controls to evaluate COVID-19 VE. To evaluate the potential bias introduced by the correlation of COVID-19 and influenza vaccination behaviors, we assessed changes in estimates of VE of bivalent vaccines against COVID-19-associated hospitalizations and emergency department/urgent care (ED/UC) encounters when considering influenza vaccination status or including or excluding influenza-positive controls using data from the multi-state VISION vaccine effectiveness network. Analyses included encounters during October 2022 - February 2023, a period of SARS-CoV-2 and influenza cocirculation. When considering influenza vaccination status or including or excluding influenza-positive controls, COVID-19 VE estimates were robust, with most VE estimates against COVID-19-associated hospitalization and ED/UC encounters changing less than 5 percentage points. Higher proportions of influenza-positive patients among controls, influenza vaccination coverage, or VE could impact these findings; the potential bias should continue to be assessed.

Racial and ethnic disparities in influenza vaccination coverage among pregnant women in the United States: The contribution of vaccine-related attitudes

OBJECTIVE

Racial and ethnic disparities in influenza vaccination coverage among pregnant women in the United States have been documented. This study assessed the contribution of vaccine-related attitudes to coverage disparities.

METHODS

Surveys were conducted following the 2019-2020 and 2020-2021 influenza seasons in a US research network. Using electronic health record data to identify pregnant women, random samples were selected for surveying; non-Hispanic Black women and influenza-unvaccinated women were oversampled. Regression-based decomposition analyses were used to assess the contribution of vaccine-related attitudes to racial and ethnic differences in influenza vaccination. Data were combined across survey years, and analyses were weighted and accounted for survey design.

RESULTS

Survey response rate was 41.2% (721 of 1748) for 2019-2020 and 39.3% (706 of 1798) for 2020-2021. Self-reported influenza vaccination was higher among non-Hispanic White respondents (79.4% coverage, 95% CI 73.1%-85.7%) than Hispanic (66.2% coverage, 95% CI 52.5%-79.9%) and non-Hispanic Black (55.8% coverage, 95% CI 50.2%-61.4%) respondents. For all racial and ethnic groups, a high proportion (generally >80%) reported being seen for care, recommended for influenza vaccination, and offered vaccination. In decomposition analyses, vaccine-related attitudes (e.g., worry about vaccination causing influenza; concern about vaccine safety and effectiveness) explained a statistically significant portion of the observed racial and ethnic disparities in vaccination. Maternal age, education, and health status were not significant contributors after controlling for vaccine-related attitudes.

CONCLUSIONS

In a setting with relatively high influenza vaccination coverage among pregnant women, racial and ethnic disparities in coverage were identified. Vaccine-related attitudes were associated with the disparities observed.

The most common medications dispensed to lactating persons: An electronic health record-based approach

PURPOSE

Using a novel, electronic health record (EHR)-based approach, to estimate the prevalence of prescription medication use at 2, 4, and 6 months postpartum among lactating individuals.

METHODS

We utilized automated EHR data from a US health system that records infant feeding information at well-child visits. We linked mothers who received prenatal care to their infants born May 2018-June 2019, and we required infants to have ≥1 well-child visit between 31 and 90 days of life (i.e., 2-month well-child visit with a ±1 month window). Mothers were classified as lactating at the 2-month well-child visit if their infant received breast milk at the 2-month well-child visit. For subsequent well-child visits at 4 and 6 months, mothers were considered lactating if their infant was still receiving breast milk.

RESULTS

We identified 6013 mothers meeting inclusion criteria, and 4158 (69.2%) were classified as lactating at the 2-month well-child visit. Among those classified as lactating, the most common medication classes dispensed around the 2-month well-child visit were oral progestin contraceptives (19.1%), selective serotonin reuptake inhibitors (8.8%), first generation cephalosporins (4.3%), thyroid hormones (3.5%), nonsteroidal anti-inflammatory agents (3.4%), penicillinase-resistant penicillins (3.1%), topical corticosteroids (2.9%), and oral imidazole-related antifungals (2.0%). The most common medication classes were similar around the 4 and 6-month well-child visits although prevalence estimates were often lower.

CONCLUSIONS

Progestin-only contraceptives, antidepressants, and antibiotics were the most dispensed medications among lactating mothers. With routine collection of breastfeeding information, mother-infant linked EHR data may overcome limitations in previous studies of medication utilization during lactation. These data should be considered for studies of medication safety during lactation given the need for human safety data.

Safety signal identification for COVID-19 bivalent booster vaccination using tree-based scan statistics in the Vaccine Safety Datalink

BACKGROUND

Traditional active vaccine safety monitoring involves pre-specifying health outcomes and biologically plausible outcome-specific time windows of concern, limiting the adverse events that can be evaluated. In this study, we used tree-based scan statistics to look broadly for >60,000 possible adverse events after bivalent COVID-19 vaccination.

METHODS

Vaccine Safety Datalink enrollees aged ≥5 years receiving Moderna or Pfizer-BioNTech bivalent COVID-19 vaccine through November 2022 were followed for 56 days post-vaccination. Incident diagnoses in inpatient or emergency department settings were analyzed for clustering within the hierarchical ICD-10-CM diagnosis code "tree" and temporally within post-vaccination follow-up. The conditional self-controlled tree-temporal scan statistic was used, conditioning on total number of cases of each diagnosis and total number of cases of any diagnosis occurring during the scanning risk window across the entire tree. P = 0.01 was the pre-specified cut-off for statistical significance.

RESULTS

Analysis included 352,509 doses of Moderna and 979,189 doses of Pfizer-BioNTech bivalent vaccines. After Moderna vaccination, no statistically significant clusters were found. After Pfizer-BioNTech, there were clusters of unspecified adverse events (Days 1-3, p = 0.0001-0.0007), influenza (Days 35-56, p = 0.0001), cough (Days 44-55, p = 0.0002), and COVID-19 (Days 52-56, p = 0.0004).

CONCLUSIONS

For Pfizer-BioNTech only, we detected clusters of: (1) unspecified adverse effects, as have been observed in other vaccine studies using this method, and (2) respiratory disease toward the end of follow-up. The respiratory clusters were likely due to overlap of follow-up with the spread of respiratory syncytial virus, influenza, and COVID-19, i.e., confounding by seasonality. The untargeted nature of the method and its inherent adjustment for the many diagnoses and risk intervals evaluated are unique advantages. Limitations include susceptibility to time-varying confounding, lower statistical power for assessing risks of specific outcomes than in traditional studies targeting fewer outcomes, and the possibility of missing adverse events not strongly clustered in time or within the "tree."

COVID-19 Vaccine Safety Surveillance in Early Pregnancy in the United States: Design Factors Affecting the Association Between Vaccine and Spontaneous Abortion

In the Vaccine Safety Datalink (VSD), we previously reported no association between coronavirus disease 2019 (COVID-19) vaccination in early pregnancy and spontaneous abortion (SAB). The present study aims to understand how time since vaccine rollout or other methodological factors could affect results. Using a case-control design and generalized estimating equations, we estimated the odds ratios (ORs) of COVID-19 vaccination in the 28 days before a SAB or last date of the surveillance period (index date) in ongoing pregnancies and occurrence of SAB, across cumulative 4-week periods from December 2020 through June 2021. Using data from a single site, we evaluated alternative methodological approaches: increasing the exposure window to 42 days, modifying the index date from the last day to the midpoint of the surveillance period, and constructing a cohort design with a time-dependent exposure model. A protective effect (OR = 0.78, 95% confidence interval: 0.69, 0.89), observed with 3-cumulative periods ending March 8, 2021, was attenuated when surveillance extended to June 28, 2021 (OR = 1.02, 95% confidence interval: 0.96, 1.08). We observed a lower OR for a 42-day window compared with a 28-day window. The time-dependent model showed no association. Timing of the surveillance appears to be an important factor affecting the observed vaccine-SAB association.

Tdap vaccination during pregnancy and risk of chorioamnionitis and related infant outcomes

INTRODUCTION

An increased risk of chorioamnionitis in people receiving tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine during pregnancy has been reported. The importance of this association is unclear as additional study has not demonstrated increased adverse infant outcomes associated with Tdap vaccination in pregnancy.

METHODS

We conducted a retrospective observational cohort study of pregnant people ages 15-49 years with singleton pregnancies ending in live birth who were members of 8 Vaccine Safety Datalink (VSD) sites during October 2016-September 2018. We used a time-dependent covariate Cox model with stabilized inverse probability weights applied to evaluate associations between Tdap vaccination during pregnancy and chorioamnionitis and preterm birth outcomes. We used Poisson regression with robust variance with stabilized inverse probability weights applied to evaluate the association of Tdap vaccination with adverse infant outcomes. We performed medical record reviews on a random sample of patients with ICD-10-CM-diagnosed chorioamnionitis to determine positive predictive values (PPV) of coded chorioamnionitisfor "probable clinical chorioamnionitis," "possible clinical chorioamnionitis," or "histologic chorioamnionitis."

RESULTS

We included 118,211 pregnant people; 103,258 (87%) received Tdap vaccine during pregnancy; 8098 (7%) were diagnosed with chorioamnionitis. The adjusted hazard ratio for chorioamnionitis in the Tdap vaccine-exposed group compared to unexposed was 0.96 (95% CI 0.90-1.03). There was no association between Tdap vaccine and preterm birth or adverse infant outcomes associated with chorioamnionitis. Chart reviews were performed for 528 pregnant people with chorioamnionitis. The PPV for clinical (probable or possible clinical chorioamnionitis) was 48% and 59% for histologic chorioamnionitis. The PPV for the combined outcome of clinical or histologic chorioamnionitis was 81%.

CONCLUSIONS AND RELEVANCE

Tdap vaccine exposure during pregnancy was not associated with chorioamnionitis, preterm birth, or adverse infant outcomes. ICD-10 codes for chorioamnionitis lack specificity for clinical chorioamnionitis and should be a recognized limitation when interpreting results.

Medically Attended Acute Adverse Events in Pregnant People After Coronavirus Disease 2019 (COVID-19) Booster Vaccination

In this multisite, observational, matched cohort study of more than 80,000 pregnant people, receipt of an mRNA monovalent coronavirus disease 2019 (COVID-19) booster vaccination in pregnancy was not associated with increased risk for thrombocytopenia, myocarditis, venous thromboembolism, ischemic stroke, or other serious adverse events within 21 or 42 days after booster vaccination. The mRNA monovalent COVID-19 booster in pregnancy was associated with an increased risk for medically attended malaise or fatigue within 7 days of vaccination (adjusted rate ratio [aRR] 3.64, 95% CI 2.42-5.48) and lymphadenopathy or lymphadenitis within 21 days (aRR 3.25, 95% CI 1.67-6.30) or 42 days (aRR 2.18, 95% CI 1.33-3.58) of vaccination. Our findings are consistent with prior evaluations of the primary COVID-19 vaccine series and are reassuring with respect to COVID-19 booster vaccination in pregnancy.

Relationships Between Social Vulnerability and Coronavirus Disease 2019 Vaccination Coverage and Vaccine Effectiveness

BACKGROUND

Coronavirus disease 2019 (COVID-19) vaccination coverage remains lower in communities with higher social vulnerability. Factors such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposure risk and access to healthcare are often correlated with social vulnerability and may therefore contribute to a relationship between vulnerability and observed vaccine effectiveness (VE). Understanding whether these factors impact VE could contribute to our understanding of real-world VE.

METHODS

We used electronic health record data from 7 health systems to assess vaccination coverage among patients with medically attended COVID-19-like illness. We then used a test-negative design to assess VE for 2- and 3-dose messenger RNA (mRNA) adult (≥18 years) vaccine recipients across Social Vulnerability Index (SVI) quartiles. SVI rankings were determined by geocoding patient addresses to census tracts; rankings were grouped into quartiles for analysis.

RESULTS

In July 2021, primary series vaccination coverage was higher in the least vulnerable quartile than in the most vulnerable quartile (56% vs 36%, respectively). In February 2022, booster dose coverage among persons who had completed a primary series was higher in the least vulnerable quartile than in the most vulnerable quartile (43% vs 30%). VE among 2-dose and 3-dose recipients during the Delta and Omicron BA.1 periods of predominance was similar across SVI quartiles.

CONCLUSIONS

COVID-19 vaccination coverage varied substantially by SVI. Differences in VE estimates by SVI were minimal across groups after adjusting for baseline patient factors. However, lower vaccination coverage among more socially vulnerable groups means that the burden of illness is still disproportionately borne by the most socially vulnerable populations.

COVID-19 Booster Vaccination in Early Pregnancy and Surveillance for Spontaneous Abortion

Importance

Adherence to COVID-19 booster vaccine recommendations has lagged in pregnant and nonpregnant adult populations. One barrier to booster vaccination is uncertainty regarding the safety of booster doses among pregnant people.

Objective

To evaluate whether there is an association between COVID-19 booster vaccination during pregnancy and spontaneous abortion.

Design, Setting, and Participants

This observational, case-control, surveillance study evaluated people aged 16 to 49 years with pregnancies at 6 to 19 weeks' gestation at 8 health systems in the Vaccine Safety Datalink from November 1, 2021, to June 12, 2022. Spontaneous abortion cases and ongoing pregnancy controls were evaluated during consecutive surveillance periods, defined by calendar time.

Exposure

Primary exposure was receipt of a third messenger RNA (mRNA) COVID-19 vaccine dose within 28 days before spontaneous abortion or index date (midpoint of surveillance period in ongoing pregnancy controls). Secondary exposures were third mRNA vaccine doses in a 42-day window or any COVID-19 booster in 28- and 42-day windows.

Main Outcomes and Measures

Spontaneous abortion cases and ongoing pregnancy controls were identified from electronic health data using a validated algorithm. Cases were assigned to a single surveillance period based on pregnancy outcome date. Eligible ongoing pregnancy time was assigned to 1 or more surveillance periods as an ongoing pregnancy-period control. Generalized estimating equations were used to estimate adjusted odds ratios (AOR) with gestational age, maternal age, antenatal visits, race and ethnicity, site, and surveillance period as covariates and robust variance estimates to account for inclusion of multiple pregnancy periods per unique pregnancy.

Results

Among 112 718 unique pregnancies included in the study, the mean (SD) maternal age was 30.6 (5.5) years. Pregnant individuals were Asian, non-Hispanic (15.1%); Black, non-Hispanic (7.5%); Hispanic (35.6%); White, non-Hispanic (31.2%); and of other or unknown (10.6%); and 100% were female. Across eight 28-day surveillance periods, among 270 853 ongoing pregnancy-period controls, 11 095 (4.1%) had received a third mRNA COVID-19 vaccine in a 28-day window; among 14 226 cases, 553 (3.9%) had received a third mRNA COVID-19 vaccine within 28 days of the spontaneous abortion. Receipt of a third mRNA COVID-19 vaccine was not associated with spontaneous abortion in a 28-day window (AOR, 0.94; 95% CI, 0.86-1.03). Results were consistent when using a 42-day window (AOR, 0.97; 95% CI, 0.90-1.05) and for any COVID-19 booster in a 28-day (AOR, 0.94; 95% CI, 0.86-1.02) or 42-day (AOR, 0.96; 95% CI, 0.89-1.04) exposure window.

Conclusions and Relevance

In this case-control surveillance study, COVID-19 booster vaccination in pregnancy was not associated with spontaneous abortion. These findings support the safety of recommendations for COVID-19 booster vaccination, including in pregnant populations.

Early Estimates of Bivalent mRNA Vaccine Effectiveness in Preventing COVID-19-Associated Emergency Department or Urgent Care Encounters and Hospitalizations Among Immunocompetent Adults - VISION Network, Nine States, September-November 2022

During June-October 2022, the SARS-CoV-2 Omicron BA.5 sublineage accounted for most of the sequenced viral genomes in the United States, with further Omicron sublineage diversification through November 2022.* Bivalent mRNA vaccines contain an ancestral SARS-CoV-2 strain component plus an updated component of the Omicron BA.4/BA.5 sublineages. On September 1, 2022, a single bivalent booster dose was recommended for adults who had completed a primary vaccination series (with or without subsequent booster doses), with the last dose administered ≥2 months earlier (1). During September 13-November 18, the VISION Network evaluated vaccine effectiveness (VE) of a bivalent mRNA booster dose (after 2, 3, or 4 monovalent doses) compared with 1) no previous vaccination and 2) previous receipt of 2, 3, or 4 monovalent-only mRNA vaccine doses, among immunocompetent adults aged ≥18 years with an emergency department/urgent care (ED/UC) encounter or hospitalization for a COVID-19-like illness.† VE of a bivalent booster dose (after 2, 3, or 4 monovalent doses) against COVID-19-associated ED/UC encounters was 56% compared with no vaccination, 32% compared with monovalent vaccination only with last dose 2-4 months earlier, and 50% compared with monovalent vaccination only with last dose ≥11 months earlier. VE of a bivalent booster dose (after 2, 3, or 4 monovalent doses) against COVID-19-associated hospitalizations was 59% compared with no vaccination, 42% compared with monovalent vaccination only with last dose 5-7 months earlier, and 48% compared with monovalent vaccination only with last dose ≥11 months earlier. Bivalent vaccines administered after 2, 3, or 4 monovalent doses were effective in preventing medically attended COVID-19 compared with no vaccination and provided additional protection compared with past monovalent vaccination only, with relative protection increasing with time since receipt of the last monovalent dose. All eligible persons should stay up to date with recommended COVID-19 vaccinations, including receiving a bivalent booster dose. Persons should also consider taking additional precautions to avoid respiratory illness this winter season, such as masking in public indoor spaces, especially in areas where COVID-19 community levels are high.

A broad assessment of covid-19 vaccine safety using tree-based data-mining in the vaccine safety datalink

BACKGROUND

Except for spontaneous reporting systems, vaccine safety monitoring generally involves pre-specifying health outcomes and post-vaccination risk windows of concern. Instead, we used tree-based data-mining to look more broadly for possible adverse events after Pfizer-BioNTech, Moderna, and Janssen COVID-19 vaccination.

METHODS

Vaccine Safety Datalink enrollees receiving ≥1 dose of COVID-19 vaccine in 2020-2021 were followed for 70 days after Pfizer-BioNTech or Moderna and 56 days after Janssen vaccination. Incident diagnoses in inpatient or emergency department settings were analyzed for clustering within both the hierarchical ICD-10-CM code structure and the post-vaccination follow-up period. We used the self-controlled tree-temporal scan statistic and TreeScan software. Monte Carlo simulation was used to estimate p-values; p = 0.01 was the pre-specified cut-off for statistical significance of a cluster.

RESULTS

There were 4.1, 2.6, and 0.4 million Pfizer-BioNTech, Moderna, and Janssen vaccinees, respectively. Clusters after Pfizer-BioNTech vaccination included: (1) unspecified adverse effects, (2) common vaccine reactions, such as fever, myalgia, and headache, (3) myocarditis/pericarditis, and (4) less specific cardiac or respiratory symptoms, all with the strongest clusters generally after Dose 2; and (5) COVID-19/viral pneumonia/sepsis/respiratory failure in the first 3 weeks after Dose 1. Moderna results were similar but without a significant myocarditis/pericarditis cluster. Further investigation suggested the fifth signal group was a manifestation of mRNA vaccine effectiveness after the first 3 weeks. Janssen vaccinees had clusters of unspecified or common vaccine reactions, gait/mobility abnormalities, and muscle weakness. The latter two were deemed to have arisen from confounding related to practices at one site.

CONCLUSIONS

We detected post-vaccination clusters of unspecified adverse effects, common vaccine reactions, and, for the mRNA vaccines, chest pain and palpitations, as well as myocarditis/pericarditis after Pfizer-BioNTech Dose 2. Unique advantages of this data mining are its untargeted nature and its inherent adjustment for the multiplicity of diagnoses and risk intervals scanned.

A safety study evaluating non-COVID-19 mortality risk following COVID-19 vaccination

BACKGROUND

The safety of COVID-19 vaccines plays an important role in addressing vaccine hesitancy. We conducted a large cohort study to evaluate the risk of non-COVID-19 mortality after COVID-19 vaccination while adjusting for confounders including individual-level demographics, clinical risk factors, health care utilization, and community-level socioeconomic risk factors.

METHODS

The retrospective cohort study consisted of members from seven Vaccine Safety Datalink sites from December 14, 2020 through August 31, 2021. We conducted three separate analyses for each of the three COVID-19 vaccines used in the US. Crude non-COVID-19 mortality rates were reported by vaccine type, age, sex, and race/ethnicity. The counting process model for survival analyses was used to analyze non-COVID-19 mortality where a new observation period began when the vaccination status changed upon receipt of the first dose and the second dose. We used calendar time as the basic time scale in survival analyses to implicitly adjust for season and other temporal trend factors. A propensity score approach was used to adjust for the potential imbalance in confounders between the vaccinated and comparison groups.

RESULTS

For each vaccine type and across age, sex, and race/ethnicity groups, crude non-COVID-19 mortality rates among COVID-19 vaccinees were lower than those among comparators. After adjusting for confounders with the propensity score approach, the adjusted hazard ratios (aHRs) were 0.46 (95% confidence interval [CI], 0.44-0.49) after dose 1 and 0.48 (95% CI, 0.46-0.50) after dose 2 of the BNT162b2 vaccine, 0.41 (95% CI, 0.39-0.44) after dose 1 and 0.38 (95% CI, 0.37-0.40) after dose 2 of the mRNA-1273 vaccine, and 0.55 (95% CI, 0.51-0.59) after receipt of Ad26.COV2.S.

CONCLUSION

While residual confounding bias remained after adjusting for several individual-level and community-level risk factors, no increased risk was found for non-COVID-19 mortality among recipients of three COVID-19 vaccines used in the US.

Tree-based data mining for safety assessment of first COVID-19 booster doses in the Vaccine Safety Datalink

BACKGROUND

The Centers for Disease Control and Prevention's Vaccine Safety Datalink (VSD) has been performing safety surveillance for COVID-19 vaccines since their earliest authorization in the United States. Complementing its real-time surveillance for pre-specified health outcomes using pre-specified risk intervals, the VSD conducts tree-based data-mining to look for clustering of a broad range of health outcomes after COVID-19 vaccination. This study's objective was to use this untargeted, hypothesis-generating approach to assess the safety of first booster doses of Pfizer-BioNTech (BNT162b2), Moderna (mRNA-1273), and Janssen (Ad26.COV2.S) COVID-19 vaccines.

METHODS

VSD enrollees receiving a first booster of COVID-19 vaccine through April 2, 2022 were followed for 56 days. Incident diagnoses in inpatient or emergency department settings were analyzed for clustering within both the hierarchical ICD-10-CM code structure and the follow-up period. The self-controlled tree-temporal scan statistic was used, conditioning on the total number of cases for each diagnosis. P-values were estimated by Monte Carlo simulation; p = 0.01 was pre-specified as the cut-off for statistical significance of clusters.

RESULTS

More than 2.4 and 1.8 million subjects received Pfizer-BioNTech and Moderna boosters after an mRNA primary series, respectively. Clusters of urticaria/allergy/rash were found during Days 10-15 after the Moderna booster (p = 0.0001). Other outcomes that clustered after mRNA boosters, mostly with p = 0.0001, included unspecified adverse effects, common vaccine-associated reactions like fever and myalgia, and COVID-19. COVID-19 clusters were in Days 1-10 after booster receipt, before boosters would have become effective. There were no noteworthy clusters after boosters following primary Janssen vaccination.

CONCLUSIONS

In this untargeted data-mining study of COVID-19 booster vaccination, a cluster of delayed-onset urticaria/allergy/rash was detected after the Moderna booster, as has been reported after Moderna vaccination previously. Other clusters after mRNA boosters were of unspecified or common adverse effects and COVID-19, the latter evidently reflecting immunity to COVID-19 after 10 days.

Early Estimates of Bivalent mRNA Vaccine Effectiveness in Preventing COVID-19-Associated Emergency Department or Urgent Care Encounters and Hospitalizations Among Immunocompetent Adults - VISION Network, Nine States, September-November 2022

During June-October 2022, the SARS-CoV-2 Omicron BA.5 sublineage accounted for most of the sequenced viral genomes in the United States, with further Omicron sublineage diversification through November 2022.* Bivalent mRNA vaccines contain an ancestral SARS-CoV-2 strain component plus an updated component of the Omicron BA.4/BA.5 sublineages. On September 1, 2022, a single bivalent booster dose was recommended for adults who had completed a primary vaccination series (with or without subsequent booster doses), with the last dose administered ≥2 months earlier (1). During September 13-November 18, the VISION Network evaluated vaccine effectiveness (VE) of a bivalent mRNA booster dose (after 2, 3, or 4 monovalent doses) compared with 1) no previous vaccination and 2) previous receipt of 2, 3, or 4 monovalent-only mRNA vaccine doses, among immunocompetent adults aged ≥18 years with an emergency department/urgent care (ED/UC) encounter or hospitalization for a COVID-19-like illness.† VE of a bivalent booster dose (after 2, 3, or 4 monovalent doses) against COVID-19-associated ED/UC encounters was 56% compared with no vaccination, 31% compared with monovalent vaccination only with last dose 2-4 months earlier, and 50% compared with monovalent vaccination only with last dose ≥11 months earlier. VE of a bivalent booster dose (after 2, 3, or 4 monovalent doses) against COVID-19-associated hospitalizations was 57% compared with no vaccination, 38% compared with monovalent vaccination only with last dose 5-7 months earlier, and 45% compared with monovalent vaccination only with last dose ≥11 months earlier. Bivalent vaccines administered after 2, 3, or 4 monovalent doses were effective in preventing medically attended COVID-19 compared with no vaccination and provided additional protection compared with past monovalent vaccination only, with relative protection increasing with time since receipt of the last monovalent dose. All eligible persons should stay up to date with recommended COVID-19 vaccinations, including receiving a bivalent booster dose. Persons should also consider taking additional precautions to avoid respiratory illness this winter season, such as masking in public indoor spaces, especially in areas where COVID-19 community levels are high.

Protection of 2 and 3 mRNA Vaccine Doses Against Severe Outcomes Among Adults Hospitalized with COVID-19 – VISION Network, August 2021 – March 2022

Background

We assessed COVID-19 vaccination impact on illness severity among adults hospitalized with COVID-19 August 2021–March 2022.

Methods

We evaluated differences in intensive care unit (ICU) admission, in-hospital death, and length of stay among vaccinated (2 or 3 mRNA vaccine doses) versus unvaccinated patients aged ≥18 years hospitalized for ≥24 hours with COVID-19-like illness (CLI) and positive SARS-CoV-2 molecular testing. We calculated odds ratios for ICU admission and death and subdistribution hazard ratios (SHR) for time to hospital discharge adjusted for age, geographic region, calendar time, and local virus circulation.

Results

We included 27,149 SARS-CoV-2 positive hospitalizations. During both Delta and Omicron-predominant periods, protection against ICU admission was strongest among 3-dose vaccinees compared with unvaccinated patients (Delta OR [CI]: 0.52 [0.28–0.96]); Omicron OR [CI]: 0.69 [0.54–0.87]). During both periods, risk of in-hospital of death was lower among vaccinated compared with unvaccinated but ORs were overlapping; during Omicron, lowest among 3-dose vaccinees (OR [CI] 0.39 [0.28–0.54]). We observed SHR &gt;1 across all vaccination strata in both periods indicating faster discharge for vaccinated patients.

Conclusions

COVID-19 vaccination was associated with lower rates of ICU admission and in-hospital death in both Delta and Omicron periods compared with being unvaccinated.

Relative Risks of COVID-19-Associated Hospitalizations and Clinical Outcomes by Age and Race/Ethnicity-March 2020-March 2021

Background

Limited data exist on population-based risks and risk ratios (RRs) of coronavirus disease 2019 (COVID-19)–associated hospitalizations and clinical outcomes stratified by age and race/ethnicity.

Methods

Using data from electronic health records and claims from 4 US health systems for the period March 2020–March 2021, we calculated risk and RR by age and race/ethnicity for COVID-19–associated hospitalizations and clinical outcomes among adults (≥18 years). COVID-19–associated hospitalizations were defined based on COVID-19 discharge codes or a positive severe acute respiratory syndrome coronavirus 2 result. Proportions of acute exacerbations of underlying conditions were estimated among hospitalized patients with select underlying conditions, stratified by age and race/ethnicity.

Results

Among 2.6 million adults included in the patient cohort, 6879 had COVID-19–associated hospitalizations during March 2020–March 2021 (risk: 264 per 100 000 population). Compared with younger, non-Hispanic White adults, non-Hispanic Black and Hispanic adults aged ≥65 years had the highest hospitalization risk ratios (RR, 8.6; 95% CI, 7.6–9.9; and RR, 9.3; 95% CI, 8.5–10.3, respectively). Among hospitalized adults with COVID-19 and renal disease or cardiovascular disease, the highest proportion of acute renal failure (55.5%) or congestive heart failure (43.9%) occurred in older, non-Hispanic Black patients. Among hospitalized adults with chronic lung disease or asthma, the highest proportion of respiratory failure (62.9%) or asthma exacerbation (66.7%) occurred in older, Hispanic patients.

Conclusions

During the first year of the US COVID-19 pandemic in this cohort, older non-Hispanic Black and Hispanic adults had the highest relative risks of COVID-19–associated hospitalization and adverse outcomes and, among those with select underlying conditions, the highest occurrences of acute exacerbations of underlying conditions.

An exploratory comparative effectiveness analysis of febrile neutropenia incidence among patients with cancer receiving granulocyte colony stimulating factors

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Background: We conducted an exploratory comparative effectiveness analysis comparing various G-CSF (pegfilgrastim/filgrastim) products to each other in incidence of febrile neutropenia (FN) among patients with breast, lung, colon, pancreatic, ovarian cancers or non-Hodgkin’s lymphoma (NHL) in the Biologics and Biosimilars Collective Intelligence Consortium’s (BBCIC) Distributed Research Network. Methods: We included patients aged > = 20 years who, in 2015-2019, per insurance claims, received any pegfilgrastim or filgrastim products as febrile neutropenia (FN) prophylaxis during the first cycle of chemotherapy posing a high or intermediate FN risk per National Comprehensive Cancer Network guidelines. We compared the FN risk starting at day 5 following day 1 of chemotherapy receipt between products using Poisson regression model with standardized inverse probability weights and robust variance to estimate the Relative Risk (RR) and 95% Confidence intervals (CI). Results: A total of 15,941 patients received a pegfilgrastim product in cycle 1 of chemotherapy: 15,115 (95%) pegfilgrastim, 484 (3%) pegfilgrastim_cbqv, 342 (2%) pegfilgrastim_jmdb. 565 patients received a filgrastim product: 284 (50%) filgrastim, 201 (36%) filgrastim_sndz, 80 (14%) tbo-filgrastim. FN events by product were: 346 pegfilgrastim (2.3% of users), 11 pegfilgrastim_cbqv (2.3%), 8 pegfilgrastim_jmdb (2.3%), 13 filgrastim (4.6%), 5 filgrastim_sndz (2.5%), 2 tbo-filgrastim (2.5%). We found no difference in FN incidence when comparing pegfilgrastim_cbqv to pegfilgrastim (RR 0.83, 95% CI 0.41-1.69), pegfilgrastim_jmdb to pegfilgrastim (RR 1.03, 95% CI 0.56-1.92), and pegfilgrastim_jmdb to pegfilgrastim_cbqv (RR 1.11, 95% CI 0.45-2.74). Similarly, we found no difference in FN incidence when comparing filgrastim_sndz to filgrastim (RR 0.46, 95% CI 0.17-1.28), tbo-filgrastim to filgrastim (RR = 0.30, 95% CI 0.06-1.36), or tbo-filgrastim to filgrastim_sndz (RR 0.54, 95% CI 0.10-2.77). Adverse events were rare, with similar rates observed among all products. Conclusions: We observed no significant difference in FN incidence among patients when comparing various G-CSF products, including when biosimilars were compared to their reference counterparts.

Estimation of COVID-19 mRNA Vaccine Effectiveness Against Medically Attended COVID-19 in Pregnancy During Periods of Delta and Omicron Variant Predominance in the United States

IMPORTANCE

Pregnant people are at high risk for severe COVID-19 but were excluded from mRNA vaccine trials; data on COVID-19 vaccine effectiveness (VE) are needed.

OBJECTIVE

To evaluate the estimated effectiveness of mRNA vaccination against medically attended COVID-19 among pregnant people during Delta and Omicron predominance.

DESIGN, SETTING, AND PARTICIPANTS

This test-negative, case-control study was conducted from June 2021 to June 2022 in a network of 306 hospitals and 164 emergency department and urgent care (ED/UC) facilities across 10 US states, including 4517 ED/UC encounters and 975 hospitalizations among pregnant people with COVID-19-like illness (CLI) who underwent SARS-CoV-2 molecular testing.

EXPOSURES

Two doses (14-149 and ≥150 days prior) and 3 doses (7-119 and ≥120 days prior) of COVID-19 mRNA vaccine (≥1 dose received during pregnancy) vs unvaccinated.

MAIN OUTCOMES AND MEASURES

Estimated VE against laboratory-confirmed COVID-19-associated ED/UC encounter or hospitalization, based on the adjusted odds ratio (aOR) for prior vaccination; VE was calculated as (1 - aOR) × 100%.

RESULTS

Among 4517 eligible CLI-associated ED/UC encounters and 975 hospitalizations, 885 (19.6%) and 334 (34.3%) were SARS-CoV-2 positive, respectively; the median (IQR) patient age was 28 (24-32) years and 31 (26-35) years, 537 (12.0%) and 118 (12.0%) were non-Hispanic Black and 1189 (26.0%) and 240 (25.0%) were Hispanic. During Delta predominance, the estimated VE against COVID-19-associated ED/UC encounters was 84% (95% CI, 69% to 92%) for 2 doses within 14 to 149 days, 75% (95% CI, 5% to 93%) for 2 doses 150 or more days prior, and 81% (95% CI, 30% to 95%) for 3 doses 7 to 119 days prior; estimated VE against COVID-19-associated hospitalization was 99% (95% CI, 96% to 100%), 96% (95% CI, 86% to 99%), and 97% (95% CI, 79% to 100%), respectively. During Omicron predominance, for ED/UC encounters, the estimated VE of 2 doses within 14 to 149 days, 2 doses 150 or more days, 3 doses within 7 to 119 days, and 3 doses 120 or more days prior was 3% (95% CI, -49% to 37%), 42% (95% CI, -16% to 72%), 79% (95% CI, 59% to 89%), and -124% (95% CI, -414% to 2%), respectively; for hospitalization, estimated VE was 86% (95% CI, 41% to 97%), 64% (95% CI, -102% to 93%), 86% (95% CI, 28% to 97%), and -53% (95% CI, -1254% to 83%), respectively.

CONCLUSIONS AND RELEVANCE

In this study, maternal mRNA COVID-19 vaccination, including booster dose, was associated with protection against medically attended COVID-19. VE estimates were higher against COVID-19-associated hospitalization than ED/UC visits and lower against the Omicron variant than the Delta variant. Protection waned over time, particularly during Omicron predominance.

Differences in the association between oral corticosteroids and risk of preterm birth by data source: Reconciling the results

OBJECTIVE

To investigate causes of discrepancies in the association between early pregnancy oral corticosteroid (OCS) use and preterm birth (PTB) risk among women with rheumatoid arthritis (RA) in health care utilization [California Medicaid (Medi-Cal)] and prospective cohort (MotherToBaby Pregnancy Studies) data.

METHODS

Separately, we estimated risk ratios (RR) between OCS exposure before gestational day 140 and PTB risk in Medi-Cal (2007-2013; n=844) and MotherToBaby (2003-2014; n=528) data. We explored differences in socio-economic status, OCS dose distribution, exposure misclassification, and confounding by RA severity across the data sources.

RESULTS

PTB risk in women without OCS's was 17.3% in Medi-Cal and was 9.7% in MotherToBaby. There was no association between OCS and PTB in Medi-Cal (adjusted (a)RR: 1.00 (95% CI: 0.71, 1.42)), and a 1.85-fold (95% CI: 1.20, 2.84) increased PTB risk in MotherToBaby. When restricting each sample to women with a high school degree or less, PTB risk following no OCS exposure was 15.9% in Medi-Cal and 16.7% in MotherToBaby; aRR's were 1.16 (95% CI: 0.74, 1.80) in Medi-Cal and 0.81 (95% CI: 0.25, 2.64) in MotherToBaby. Cumulative OCS dose was higher in MotherToBaby (median: 684 mg) than Medi-Cal (median: 300 mg). OCS dose ≤300 mg was not associated with increased PTB risk. Exposure misclassification and confounding by RA severity were unlikely explanations of differences.

DISCUSSION

Higher baseline PTB risk and lower OCS dose distribution in Medi-Cal may explain the discrepancies. Studies are needed to understand the effects of autoimmune disease severity and under-treatment on PTB risk in low-income populations.

Association of the COVID-19 Pandemic With Routine Childhood Vaccination Rates and Proportion Up to Date With Vaccinations Across 8 US Health Systems in the Vaccine Safety Datalink

IMPORTANCE

The COVID-19 pandemic has affected routine vaccine delivery in the US and globally. The magnitude of these disruptions and their association with childhood vaccination coverage are unclear.

OBJECTIVES

To compare trends in pediatric vaccination before and during the pandemic and to evaluate the proportion of children up to date (UTD) with vaccinations by age, race, and ethnicity.

DESIGN, SETTING, AND PARTICIPANTS

This surveillance study used a prepandemic-postpandemic control design with data from 8 health systems in California, Oregon, Washington, Colorado, Minnesota, and Wisconsin in the Vaccine Safety Datalink. Children from age groups younger than 24 months and 4 to 6, 11 to 13, and 16 to 18 years were included if they had at least 1 week of health system enrollment from January 5, 2020, through October 3, 2020, over periods before the US COVID-19 pandemic (January 5, 2020, through March 14, 2020), during age-limited preventive care (March 15, 2020, through May 16, 2020), and during expanded primary care (May 17, 2020, through October 3, 2020). These individuals were compared with those enrolled during analogous weeks in 2019.

EXPOSURES

This study evaluated UTD status among children reaching specific ages in February, May, and September 2020, compared with those reaching these ages in 2019.

MAIN OUTCOMES AND MEASURES

Weekly vaccination rates for routine age-specific vaccines and the proportion of children UTD for all age-specific recommended vaccines.

RESULTS

Of 1 399 708 children in 2019 and 1 402 227 in 2020, 1 371 718 were female (49.0%) and 1 429 979 were male (51.0%); 334 216 Asian individuals (11.9%), 900 226 were Hispanic individuals (32.1%), and 201 619 non-Hispanic Black individuals (7.2%). Compared with the prepandemic period and 2019, the age-limited preventive care period was associated with lower weekly vaccination rates, with ratios of rate ratios of 0.82 (95% CI, 0.80-0.85) among those younger than 24 months, 0.18 (95% CI, 0.16-0.20) among those aged 4 to 6 years, 0.16 (95% CI, 0.14-0.17) among those aged 11 to 13 years, and 0.10 (95% CI, 0.08-0.13) among those aged 16 to 18 years. Vaccination rates during expanded primary care remained lower for most ages (ratios of rate ratios: <24 months, 0.96 [95% CI, 0.93-0.98]; 11-13 years, 0.81 [95% CI, 0.76-0.86]; 16-18 years, 0.57 [95% CI, 0.51-0.63]). In September 2020, 74% (95% CI, 73%-76%) of infants aged 7 months and 57% (95% CI, 56%-58%) of infants aged 18 months were UTD vs 81% (95% CI, 80%-82%) and 61% (95% CI, 60%-62%), respectively, in September 2019. The proportion UTD was lowest in non-Hispanic Black children across most age groups, both during and prior to the COVID-19 pandemic (eg, in May 2019, 70% [95% CI, 64%-75%] of non-Hispanic Black infants aged 7 months were UTD vs 82% [95% CI, 81%-83%] in all infants aged 7 months combined).

CONCLUSIONS AND RELEVANCE

As of September 2020, childhood vaccination rates and the proportion who were UTD remained lower than 2019 levels. Interventions are needed to promote catch-up vaccination, particularly in populations at risk for underimmunization.

Using a brief tool to assess healthy school environments: a pilot study

OBJECTIVES

HealthPartners developed a checklist, the School Environment Index (SEI), that it uses to help elementary schools identify opportunities to improve student nutrition and increase physical activity. The objective in this pilot study was to assess whether the SEI, as administered, can be used to measure the progress of these programs.

STUDY DESIGN

The authors focused their evaluation on the National Quality Forum measure evaluation components of reliability and validity; feasibility; and use and usability to assess the SEI's performance.

METHODS

The authors used data from 214 SEIs completed by the 69 schools that participated in the school challenge in at least 1 of the years 2015 through 2019. Between 29 and 53 schools participated in a particular year.

RESULTS

Cronbach's α was 0.79, intraclass correlation was 0.36 (95% CI, 0.22-0.53), and sensitivity to change was 0.41 (95% CI, 0.17-0.66) per 1-year change in the standardized SEI score. The median (interquartile range) time required to complete the survey was 11 (7-21) minutes. On only 8 surveys was an entire domain of the SEI skipped or only a single response to the domain recorded.

CONCLUSIONS

The SEI shows adequate internal consistency and sensitivity to change in this pilot evaluation. It is also feasible and useful to identify opportunities to improve practices and policies related to student nutrition and physical activity in partnership with the participating elementary schools. However, it lacks reliability as used. Increasing the number of respondents per school might moderate the impact of individual respondents and thereby increase reliability.

COVID-19 Vaccination and Non-COVID-19 Mortality Risk - Seven Integrated Health Care Organizations, United States, December 14, 2020-July 31, 2021

By September 21, 2021, an estimated 182 million persons in the United States were fully vaccinated against COVID-19.* Clinical trials indicate that Pfizer-BioNTech (BNT162b2), Moderna (mRNA-1273), and Janssen (Johnson & Johnson; Ad.26.COV2.S) vaccines are effective and generally well tolerated (1-3). However, daily vaccination rates have declined approximately 78% since April 13, 2021^†; vaccine safety concerns have contributed to vaccine hesitancy (4). A cohort study of 19,625 nursing home residents found that those who received an mRNA vaccine (Pfizer-BioNTech or Moderna) had lower all-cause mortality than did unvaccinated residents (5), but no studies comparing mortality rates within the general population of vaccinated and unvaccinated persons have been conducted. To assess mortality not associated with COVID-19 (non-COVID-19 mortality) after COVID-19 vaccination in a general population setting, a cohort study was conducted during December 2020-July 2021 among approximately 11 million persons enrolled in seven Vaccine Safety Datalink (VSD) sites.^§ After standardizing mortality rates by age and sex, this study found that COVID-19 vaccine recipients had lower non-COVID-19 mortality than did unvaccinated persons. After adjusting for demographic characteristics and VSD site, this study found that adjusted relative risk (aRR) of non-COVID-19 mortality for the Pfizer-BioNTech vaccine was 0.41 (95% confidence interval [CI] = 0.38-0.44) after dose 1 and 0.34 (95% CI = 0.33-0.36) after dose 2. The aRRs of non-COVID-19 mortality for the Moderna vaccine were 0.34 (95% CI = 0.32-0.37) after dose 1 and 0.31 (95% CI = 0.30-0.33) after dose 2. The aRR after receipt of the Janssen vaccine was 0.54 (95% CI = 0.49-0.59). There is no increased risk for mortality among COVID-19 vaccine recipients. This finding reinforces the safety profile of currently approved COVID-19 vaccines in the United States.

Spontaneous Abortion Following COVID-19 Vaccination During Pregnancy

This study presents findings from case-control surveillance of COVID-19 vaccination during pregnancy and spontaneous abortion.

Association of Cardiovascular Outcomes and Mortality With Sustained Long-Acting Insulin Only vs Long-Acting Plus Short-Acting Insulin Treatment

IMPORTANCE

Cardiovascular events and mortality are the principal causes of excess mortality and health care costs for people with type 2 diabetes. No large studies have specifically compared long-acting insulin alone with long-acting plus short-acting insulin with regard to cardiovascular outcomes.

OBJECTIVE

To compare cardiovascular events and mortality in adults with type 2 diabetes receiving long-acting insulin who do or do not add short-acting insulin.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study emulated a randomized experiment in which adults with type 2 diabetes who experienced a qualifying glycated hemoglobin A1c (HbA1c) level of 6.8% to 8.5% with long-acting insulin were randomized to continuing treatment with long-acting insulin (LA group) or adding short-acting insulin within 1 year of the qualifying HbA1c level (LA plus SA group). Retrospective data in 4 integrated health care delivery systems from the Health Care Systems Research Network from January 1, 2005, to December 31, 2013, were used. Analysis used inverse probability weighting estimation with Super Learner for propensity score estimation. Analyses took place from April 1, 2018, to June 30, 2019.

EXPOSURES

Long-acting insulin alone or with added short-acting insulin within 1 year from the qualifying HbA1c level.

MAIN OUTCOMES AND MEASURES

Mortality, cardiovascular mortality, acute myocardial infarction, stroke, and hospitalization for heart failure.

RESULTS

Among 57 278 individuals (39 279 with data on cardiovascular mortality) with a mean (SD) age of 60.6 (11.5) years, 53.6% men, 43.5% non-Hispanic White individuals, and 4 years of follow-up (median follow-up of 11 [interquartile range, 5-20] calendar quarters), the LA plus SA group was associated with increased all-cause mortality compared with the LA group (hazard ratio, 1.27; 95% CI, 1.05-1.49) and a decreased risk of acute myocardial infarction (hazard ratio, 0.89; 95% CI, 0.81-0.97). Treatment with long-acting plus short-acting insulin was not associated with increased risks of congestive heart failure, stroke, or cardiovascular mortality.

CONCLUSIONS AND RELEVANCE

Findings of this retrospective cohort study suggested an increased risk of all-cause mortality and a decreased risk of acute myocardial infarction for the LA plus SA group compared with the LA group. Given the lack of an increase in major cardiovascular events or cardiovascular mortality, the increased all-cause mortality with long-acting plus short-acting insulin may be explained by noncardiovascular events or unmeasured confounding.

Comparison of Medical School Financing Plans Among Matriculating US Medical Students From 2017 to 2019

This survey study explores US students’ financing plans for medical school overall and by several demographic factors, focusing on race/ethnicity and household income.

Vaccine Safety Datalink infrastructure enhancements for evaluating the safety of maternal vaccination

BACKGROUND

Identifying pregnancy episodes and accurately estimating their beginning and end dates are imperative for observational maternal vaccine safety studies using electronic health record (EHR) data.

METHODS

We modified the Vaccine Safety Datalink (VSD) Pregnancy Episode Algorithm (PEA) to include both the International Classification of Disease, ninth revision (ICD-9 system) and ICD-10 diagnosis codes, incorporated additional gestational age data, and validated this enhanced algorithm with manual medical record review. We also developed the new Dynamic Pregnancy Algorithm (DPA) to identify pregnancy episodes in real time.

RESULTS

Around 75% of the pregnancy episodes identified by the enhanced VSD PEA were live births, 12% were spontaneous abortions (SABs), 10% were induced abortions (IABs), and 0.4% were stillbirths (SBs). Gestational age was identified for 99% of live births, 89% of SBs, 69% of SABs, and 42% of IABs. Agreement between the PEA-assigned and abstractor-identified pregnancy outcome and outcome date was 100% for live births, but was lower for pregnancy losses. When gestational age was available in the medical record, the agreement was higher for live births (97%), but lower for pregnancy losses (75%). The DPA demonstrated strong concordance with the PEA and identified pregnancy episodes ⩾6 months prior to the outcome date for 89% of live births.

CONCLUSION

The enhanced VSD PEA is a useful tool for identifying pregnancy episodes in EHR databases. The DPA improves the timeliness of pregnancy identification and can be used for near real-time maternal vaccine safety studies.

PLAIN LANGUAGE SUMMARY

Improving identification of pregnancies in the Vaccine Safety Datalink electronic medical record databases to allow for better and faster monitoring of vaccination safety during pregnancy Introduction: It is important to monitor of the safety of vaccines after they have been approved and licensed by the Food and Drug Administration, especially among women vaccinated during pregnancy. The Vaccine Safety Datalink (VSD) monitors vaccine safety through observational studies within large databases of electronic medical records. Since 2012, VSD researchers have used an algorithm called the Pregnancy Episode Algorithm (PEA) to identify the medical records of women who have been pregnant. Researchers then use these medical records to study whether receiving a particular vaccine is linked to any negative outcomes for the woman or her child.Methods: The goal of this study was to update and enhance the PEA to include the full set of medical record diagnostic codes [both from the older International Classification of Disease, ninth revision (ICD-9 system) and the newer ICD-10 system] and to incorporate additional sources of data about gestational age. To ensure the validity of the PEA following these enhancements, we manually reviewed medical records and compared the results with the algorithm. We also developed a new algorithm, the Dynamic Pregnancy Algorithm (DPA), to identify women earlier in pregnancy, allowing us to conduct more timely vaccine safety assessments.Results: The new version of the PEA identified 2,485,410 pregnancies in the VSD database. The enhanced algorithm more precisely estimated the beginning of pregnancies, especially those that did not result in live births, due to the new sources of gestational age data.Conclusion: Our new algorithm, the DPA, was successful at identifying pregnancies earlier in gestation than the PEA. The enhanced PEA and the new DPA will allow us to better evaluate the safety of current and future vaccinations administered during or around the time of pregnancy.

Association of Inadvertent 9-Valent Human Papillomavirus Vaccine in Pregnancy With Spontaneous Abortion and Adverse Birth Outcomes

IMPORTANCE

The 9-valent human papillomavirus (9vHPV) vaccine is recommended for individuals through age 26 years and may be administered to women up to age 45 years. Data on 9vHPV vaccine exposures during pregnancy are limited.

OBJECTIVE

To evaluate the associations between 9vHPV vaccine exposures during pregnancy or peripregnancy and selected pregnancy and birth outcomes (spontaneous abortion [SAB], preterm birth, small-for-gestational age [SGA] birth, and major structural birth defect).

DESIGN, SETTING, AND PARTICIPANTS

This cohort study analyzed data from 7 participating health systems in the Vaccine Safety Datalink. The cohort comprised pregnancies among girls and women aged 12 to 28 years that ended between October 26, 2015, and November 15, 2018. Singleton pregnancies that ended in a live birth, stillbirth, or SAB were included.

EXPOSURES

Vaccine exposure windows were distal (9vHPV or 4vHPV vaccine administered from 22 to 16 weeks before last menstrual period [LMP]), peripregnancy (9vHPV vaccine administered from 42 days before LMP until LMP), and during pregnancy (9vHPV vaccine administered from LMP to 19 completed weeks' gestation). Primary comparisons were (1) girls and women with 9vHPV vaccine exposures during pregnancy vs those with 4vHPV or 9vHPV distal vaccine exposures, (2) girls and women with vaccine exposures peripregnancy vs those with 4vHPV or 9vHPV distal vaccine exposures, and (3) girls and women with 9vHPV vaccine exposures during pregnancy or peripregnancy vs those with 4vHPV or 9vHPV distal vaccine exposure.

MAIN OUTCOMES AND MEASURES

Spontaneous abortions were confirmed based on medical record review and adjudication. Preterm and SGA births were identified from electronic health record and birth data. Major structural birth defects were based on diagnostic codes using a validated algorithm. Inverse probability weighting was used to balance the covariates. Time-dependent covariate Cox proportional hazards regression models and Poisson regression were used to estimate the associations between 9vHPV vaccine exposures and pregnancy and birth outcomes.

RESULTS

The final cohort included 1493 pregnancies among girls and women with a mean (SD) maternal age of 23.9 (2.9) years. Of these pregnancies, 445 (29.8%) had exposures to the 9vHPV vaccine during pregnancy, 496 (33.2%) had exposures to the 9vHPV vaccine peripregnancy, and 552 (37.0%) had 4vHPV or 9vHPV distal vaccine exposures. The 9vHPV vaccine administered during pregnancy was not associated with increased risk for SAB (hazard ratio, 1.12; 95% CI, 0.66-1.93) compared with distal vaccine exposures. Findings were similar for 9vHPV vaccine exposures peripregnancy (relative risk [RR], 0.72; 95% CI, 0.42-1.24). Among live births (n = 1409), 9vHPV vaccine exposures during pregnancy were not associated with increased risks for preterm birth (RR, 0.73; 95% CI, 0.44-1.20) or SGA birth (RR, 1.31; 95% CI, 0.78-2.20). Results were similar regarding the association between 9vHPV vaccine exposures peripregnancy and preterm birth (RR, 0.72; 95% CI, 0.45-1.17) and SGA birth (RR, 1.10; 95% CI, 0.65-1.88). Birth defects were rare in all exposure groups, occurring in about 1% of live births with available infant data.

CONCLUSIONS AND RELEVANCE

This study found that 9vHPV vaccine exposures during or around the time of pregnancy were uncommon and not associated with SABs or selected adverse birth outcomes. These findings can inform counseling for inadvertent 9vHPV vaccine exposures.

Effect of Clinical Decision Support on Diagnostic Imaging for Pediatric Appendicitis: A Cluster Randomized Trial

IMPORTANCE

Appendicitis is the most common pediatric surgical emergency. Efforts to improve efficiency and quality of care have increased reliance on computed tomography (CT) and ultrasonography (US) in children with suspected appendicitis.

OBJECTIVE

To evaluate the effectiveness of an electronic health record-linked clinical decision support intervention, AppyCDS, on diagnostic imaging, health care costs, and safety outcomes for patients with suspected appendicitis.

DESIGN, SETTING, AND PARTICIPANTS

In this parallel, cluster randomized trial, 17 community-based general emergency departments (EDs) in California, Minnesota, and Wisconsin were randomized to the AppyCDS intervention group or usual care (UC) group. Patients were aged 5 to 20 years, presenting for an ED visit with right-sided or diffuse abdominal pain lasting 5 days or less. We excluded pregnant patients, those with a prior appendectomy, those with selected comorbidities, and those with traumatic injuries. The trial was conducted from October 2016 to July 2019.

INTERVENTIONS

AppyCDS prompted data entry at the point of care to estimate appendicitis risk using the pediatric appendicitis risk calculator (pARC). Based on pARC estimates, AppyCDS recommended next steps in care.

MAIN OUTCOMES AND MEASURES

Primary outcomes were CT, US, or any imaging (CT or US) during the index ED visit. Safety outcomes were perforations, negative appendectomies, and missed appendicitis. Costs were a secondary outcome. Ratio of ratios (RORs) for primary and safety outcomes and differences by group in cost were used to evaluate effectiveness of the clinical decision support tool.

RESULTS

We enrolled 3161 patients at intervention EDs and 2779 patients at UC EDs. The mean age of patients was 11.9 (4.6) years and 2614 (44.0%) were boys or young men. RORs for CT (0.94; 95% CI, 0.75-1.19), US (0.98; 95% CI, 0.84-1.14), and any imaging (0.96; 95% CI, 0.86-1.07) did not differ by study group. In an exploratory analysis conducted in 1 health system, AppyCDS was associated with a reduction in any imaging (ROR, 0.82; 95% CI, 0.73- 0.93) for patients with pARC score of 15% or less and a reduction in CT (ROR, 0.58; 95% CI, 0.45-0.74) for patients with a pARC score of 16% to 50%. Perforations, negative appendectomies, and cases of missed appendicitis by study phase did not differ significantly by study group. Costs did not differ overall by study group.

CONCLUSIONS AND RELEVANCE

In this study, AppyCDS was not associated with overall reductions in diagnostic imaging; exploratory analysis revealed more appropriate use of imaging in patients with a low pARC score.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02633735.

Developing algorithms for identifying major structural birth defects using automated electronic health data

PURPOSE

Given the 2015 transition to International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnostic coding, updates to our previously published algorithms for major structural birth defects (BDs) were necessary. Aims of this study were to update, validate, and refine algorithms for identifying selected BDs, and then to use these algorithms to describe BD prevalence in the vaccine safety datalink (VSD) population.

METHODS

We converted our ICD-9-CM list of selected BDs to ICD-10-CM using available crosswalks with manual review of codes. We identified, chart reviewed, and adjudicated a sample of infants in the VSD with ≥2 ICD-10-CM diagnoses for one of seven common BDs. Positive predictive values (PPVs) were calculated; for BDs with suboptimal PPV, algorithms were refined. Final automated algorithms were applied to a cohort of live births delivered 10/1/2015-9/30/2017 at eight VSD sites to estimate BD prevalence. This research was approved by the HealthPartners Institutional Review Board, by all participating VSD sites, and by the CDC, with a waiver of informed consent.

RESULTS

Of 573 infants with ≥2 diagnoses for a targeted BD, on adjudication, we classified 399 (69.6%) as probable cases, 31 (5.4%) as possible cases and 143 (25.0%) as not having the targeted BD. PPVs for the final BD algorithms ranged from 0.76 (hypospadias) to 1.0 (gastroschisis). Among 212 857 births over 2 years following transition to ICD-10-CM coding, prevalence for the full list of selected defects in the VSD was 1.8%.

CONCLUSIONS

Algorithms can identify infants with selected BDs using automated healthcare data with reasonable accuracy. Our updated algorithms can be used in observational studies of maternal vaccine safety and may be adapted for use in other surveillance systems.

An Analysis of Changes in Emergency Department Visits After a State Declaration During the Time of COVID-19

STUDY OBJECTIVE

In the initial period of the coronavirus disease 2019 (COVID-19) pandemic, there has been a substantial decrease in the number of patients seeking care in the emergency department. A first step in estimating the impact of these changes is to characterize the patients, visits, and diagnoses for whom care is being delayed or deferred.

METHODS

We conducted an observational study, examining demographics, visit characteristics, and diagnoses for all ED patient visits to an urban level 1 trauma center before and after a state emergency declaration and comparing them with a similar period in 2019. We estimated percent change on the basis of the ratios of before and after periods with respect to 2019 and the decline per week using Poisson regression. Finally, we evaluated whether each factor modified the change in overall ED visits.

RESULTS

After the state declaration, there was a 49.3% decline in ED visits overall, 35.2% (95% confidence interval -38.4 to -31.9) as compared with 2019. Disproportionate declines were seen in visits by pediatric and older patients, women, and Medicare recipients, as well as for presentations of syncope, cerebrovascular accidents, urolithiasis, and abdominal and back pain. Significant proportional increases were seen in ED visits for upper respiratory infections, shortness of breath, and chest pain.

CONCLUSION

There have been significant changes in patterns of care seeking during the COVID-19 pandemic. Declines in ED visits, especially for certain demographic groups and disease processes, should prompt efforts to understand these phenomena, encourage appropriate care seeking, and monitor for the morbidity and mortality that may result from delayed or deferred care.

The effects of financial incentives on diabetes prevention program attendance and weight loss among low-income patients: the We Can Prevent Diabetes cluster-randomized controlled trial

BACKGROUND

Penetration and participation of real life implementation of lifestyle change programs to prevent type 2 diabetes has been challenging. This is particularly so among low income individuals in the United States. The purpose of this study is to examine the effectiveness of financial incentives on attendance and weight loss among Medicaid beneficiaries participating in the 12-month Diabetes Prevention Program (DPP).

METHODS

This is a cluster-randomized controlled trial with two financial incentive study arms and an attention control study arm. Medicaid beneficiaries with prediabetes from 13 primary care clinics were randomly assigned to individually earned incentives (IND; 33 groups; n = 309), a hybrid of individual- and group-earned incentives (GRP; 30 groups; n = 259), and an attention control (AC; 30 groups; n = 279). Up to $520 in incentives could be earned for attaining attendance and weight loss goals over 12 months. Outcomes are percent weight loss from baseline, achieving 5% weight loss from baseline, and attending 75% of core and 75% of maintenance DPP sessions. Linear mixed models were used to examine weight change and attendance rates over the 16 weeks and 12 months.

RESULTS

The percent weight change at 16 weeks for the IND, GRP, and AC participants were similar, at - 2.6, - 3.1%, and - 3.4%, respectively. However, participants achieving 5% weight loss in the IND, GRP, and AC groups was 21.5, 24.0% (GRP vs AC, P < 0.05), and 15.2%. Attendance at 75% of the DPP core sessions was significantly higher among IND (60.8%, P < 0.001) and GRP (64.0%, P < 0.001) participants than among AC (38.6%) participants. Despite substantial attrition over time, attendance at 75% of the DPP maintenance sessions was also significantly higher among IND (23.0%, P < 0.001) and GRP (26.1%, P < 0.001) participants than among AC (11.0%) participants.

CONCLUSIONS

Financial incentives can improve the proportion of Medicaid beneficiaries attending the 12-month DPP and achieving at least 5% weight loss.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02422420 ; retrospectively registered April 21, 2015.

Diagnostic Performance of Emergency Physician Gestalt for Predicting Acute Appendicitis in Patients Age 5 to 20 Years

OBJECTIVES

Pediatric appendicitis remains a challenging diagnosis in the emergency department (ED). Available risk prediction algorithms may contribute to excessive ED imaging studies. Incorporation of physician gestalt assessment could help refine predictive tools and improve diagnostic imaging decisions.

METHODS

This study was a subanalysis of a parent study that prospectively enrolled patients ages 5 to 20.9 years with a chief complaint of abdominal pain presenting to 11 community EDs within an integrated delivery system between October 1, 2016, and September 30, 2018. Prior to diagnostic imaging, attending emergency physicians enrolled patients with ≤5 days of right-sided or diffuse abdominal pain using a Web-based application embedded in the electronic health record. Predicted risk (gestalt) of acute appendicitis was prospectively entered using a sliding scale from 1% to 100%. As a planned secondary analysis, we assessed the performance of gestalt via c-statistics of receiver operating characteristic (ROC) curves; tested associations between gestalt performance and patient, physician, and facility characteristics; and examined clinical characteristics affecting gestalt estimates.

RESULTS

Of 3,426 patients, 334 (9.8%) had confirmed appendicitis. Physician gestalt had excellent ROC curve characteristics (c-statistic = 0.83, 95% confidence interval = 0.81 to 0.85), performing particularly well in the low-risk strata (appendicitis rate = 1.1% in gestalt 1%-10% range, negative predictive value of 98.9% for appendicitis diagnosis). Physicians with ≥5 years since medical school graduation demonstrated improved gestalt performance over those with less experience (p = 0.007). All clinical characteristics tested, except pain <24 hours, were significantly associated with physician gestalt value (p < 0.05).

CONCLUSION

Physician gestalt for acute appendicitis diagnosis performed well, especially in low-risk patients and when employed by experienced physicians.

Oral corticosteroid use during pregnancy and risk of preterm birth

OBJECTIVE

To evaluate the associations between oral corticosteroid (OCS) dose early and late in pregnancy and preterm birth (PTB) among women with RA.

METHODS

Pregnant women in the MotherToBaby Pregnancy Studies (2003-2014) with RA (n = 528) were included in the primary analysis. Information was collected by phone interview and from medical records. We estimated risk ratios (RR) for OCS dose trajectories and other disease-related medications before gestational day 140 and hazard ratios (HR) for time-varying exposures after gestational day 139.

RESULTS

PTB risk was 15.5% overall. Compared with no OCS, PTB risk was increased in high (adjusted (a)RR: 4.77 (95% CI: 2.76, 8.26)) and medium (aRR: 1.81 (95% CI: 1.10, 2.97)) cumulative OCS dose trajectories during the first 139 gestational days. The low cumulative trajectory group was associated with an increased risk of PTB that was not statistically significant (aRR: 1.38 (95% CI: 0.79, 2.38)), and DMARDs were not associated with PTB (biologic DMARDs aHR: 1.08 (95% CI: 0.70, 1.66); non-biologic DMARDs aHR: 0.87 (95% CI: 0.55, 1.38)). OCS exposure to ⩾10 mg of prednisone equivalent daily dose after gestational day 139 vs none was associated with increased PTB rate (aHR: 2.45 (95% CI: 1.32, 4.56)), whereas <10 mg was associated with a modestly increased rate of PTB that was not statistically significant (aHR: 1.18 (95% CI: 0.60, 2.30)).

CONCLUSION

Higher OCS doses vs no OCS use, both earlier and later in pregnancy, were associated with an increase in PTB among women with RA.

Oral Corticosteroids and Risk of Preterm Birth in the California Medicaid Program

BACKGROUND

There is limited information regarding the impact of dose and gestational timing of oral corticosteroid (OCS) use on preterm birth (PTB), especially among women with asthma.

OBJECTIVES

To evaluate OCS dose and timing on PTB for asthma and, as a comparison, systemic lupus erythematosus (SLE).

METHODS

We used health care data from California Medicaid enrollees linked to birth certificates (2007-2013), identifying women with asthma (n = 22,084) and SLE (n = 1174). We estimated risk ratios (RR) for OCS cumulative dose trajectories and other disease-related medications before gestational day 140 and hazard ratios (HR) for time-varying exposures after day 139.

RESULTS

For asthma, PTB risk was 14.0% for no OCS exposure and 14.3%, 16.8%, 20.5%, and 32.7% in low, medium, medium-high, and high cumulative dose trajectory groups, respectively, during the first 139 days. The high-dose group remained associated with PTB after adjustment (adjusted RR [aRR]: 1.46; 95% confidence interval [CI]: 1.00, 2.15). OCS dose after day 139 was not clearly associated with PTB, nor were controller medications. For SLE, PTB risk for no OCS exposure was 24.9%, and it was 39.1% in low- and 61.2% in high-dose trajectory groups. aRR were 1.80 (95% CI: 1.34, 2.40) for high and 1.24 (95% CI: 0.97, 1.58) for low groups. Only prednisone equivalent dose >20 mg/day after day 139 was associated with increased PTB (adjusted HR: 2.54; 95% CI: 1.60, 4.03).

CONCLUSIONS

For asthma, higher OCS doses early in pregnancy, but not later, were associated with increased PTB. For SLE, higher doses early and later in pregnancy were associated with PTB.

Comparison of Mortality and Major Cardiovascular Events Among Adults With Type 2 Diabetes Using Human vs Analogue Insulins

Importance

The comparative cardiovascular safety of analogue and human insulins in adults with type 2 diabetes who initiate insulin therapy in usual care settings has not been carefully evaluated using machine learning and other rigorous analytic methods.

Objective

To examine the association of analogue vs human insulin use with mortality and major cardiovascular events.

Design, Setting, and Participants

This retrospective cohort study included 127 600 adults aged 21 to 89 years with type 2 diabetes at 4 health care delivery systems who initiated insulin therapy from January 1, 2000, through December 31, 2013. Machine learning and rigorous inference methods with time-varying exposures were used to evaluate associations of continuous exposure to analogue vs human insulins with mortality and major cardiovascular events. Data were analyzed from September 1, 2017, through June 30, 2018.

Exposures

On the index date (first insulin dispensing), participants were classified as using analogue insulin with or without human insulin or human insulin only.

Main Outcomes and Measures

Overall mortality, mortality due to cardiovascular disease (CVD), myocardial infarction (MI), stroke or cerebrovascular accident (CVA), and hospitalization for congestive heart failure (CHF) were evaluated. Marginal structural modeling (MSM) with inverse probability weighting was used to compare event-free survival in separate per-protocol analyses. Adjusted and unadjusted hazard ratios and cumulative risk differences were based on logistic MSM parameterizations for counterfactual hazards. Propensity scores were estimated using a data-adaptive approach (machine learning) based on 3 nested covariate adjustment sets. Sensitivity analyses were conducted to address potential residual confounding from unmeasured differences in risk factors across delivery systems.

Results

The 127 600 participants (mean [SD] age, 59.4 [12.6] years; 68 588 men [53.8%]; mean [SD] body mass index, 32.3 [7.1]) had a median follow-up of 4 quarters (interquartile range, 3-9 quarters) and experienced 5464 deaths overall (4.3%), 1729 MIs (1.4%), 1301 CVAs (1.0%), and 3082 CHF hospitalizations (2.4%). There were no differences in adjusted hazard ratios for continuous analogue vs human insulin exposure during 10 quarters for overall mortality (1.15; 95% CI, 0.97-1.34), CVD mortality (1.26; 95% CI, 0.86-1.66), MI (1.11; 95% CI, 0.77-1.45), CVA (1.30; 95% CI, 0.81-1.78), or CHF hospitalization (0.93; 95% CI, 0.75-1.11).

Conclusions and Relevance

Insulin-naive adults with type 2 diabetes who initiate and continue treatment with human vs analogue insulins had similar observed rates of major cardiovascular events, CVD mortality, and overall mortality.

A randomized trial of medical cannabis (MC) in patients with advanced cancer (AC) to assess impact on opioid use and cancer-related symptoms

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Background: Higher pain and greater long-term opioid requirements have been associated with shorter survival and decreased quality of life (QOL) in patients with AC. Routine use of MC is limited by a lack of rigorous scientific data and concerns about side effects, legal ramifications, and cost. Methods: 30 patients with stage IV cancer requiring opioids were randomized 1:1 to early cannabis (EC, n=15) vs. delayed cannabis (DC, n=15). The EC group was provided with 3 months (3M) of MC at no charge, while the DC group received standard oncology care without MC for the first 3M. Patients met with licensed pharmacists at one of two MC manufacturers to determine optimal MC dosing, formulation, and route. Patients completed monthly pain logs, opioid/MC logs, and validated Patient-Reported Symptom Monitoring surveys. Results: A higher proportion of EC patients achieved a reduction in opioid use and improved pain control. On average over a 3M window, EC patients did not require opioid dose escalation, had lower mean pain, and had similar QOL compared to DC patients. Estimated mean daily THC and CBD dose at 3M was 76 mg (range 5-186 mg) and 36 mg (range <1-516 mg), respectively. Mean perceived benefit of MC was 5.1 and mean perceived negative impact was 2.7 (1 = no benefit/negative effects, 7 = a great deal of benefit/negative effects). 33% of patients died during the anticipated 6-month study period and patient compliance with study logs limited analysis. Conclusions: Randomized studies of MC in the oncology setting are feasible, but rigorous data collection is challenging. The addition of MC to standard oncology care in patients with AC was well-tolerated and may lead to improved pain control and lower opioid requirements. [Table: see text]

Validation of the Pediatric Appendicitis Risk Calculator (pARC) in a Community Emergency Department Setting

STUDY OBJECTIVE

The pediatric Appendicitis Risk Calculator (pARC) is a validated clinical tool for assessing a child's probability of appendicitis. Our objective was to assess the performance of the pARC in community emergency departments (EDs) and to compare its performance with that of the Pediatric Appendicitis Score (PAS).

METHODS

We conducted a prospective validation study from October 1, 2016, to April 30, 2018, in 11 community EDs serving general populations. Patients aged 5 to 20.9 years and with a chief complaint of abdominal pain and less than or equal to 5 days of right-sided or diffuse abdominal pain were eligible for study enrollment. Our primary outcome was the presence or absence of appendicitis within 7 days of the index visit. We reported performance characteristics and secondary outcomes by pARC risk strata and compared the receiver operator characteristic (ROC) curves of the PAS and pARC.

RESULTS

We enrolled 2,089 patients with a mean age of 12.4 years, 46% of whom were male patients. Appendicitis was confirmed in 353 patients (16.9%), of whom 55 (15.6%) had perforated appendixes. Fifty-four percent of patients had very low (<5%) or low (5% to 14%) predicted risk, 43% had intermediate risk (15% to 84%), and 4% had high risk (≥85%). In the very-low- and low-risk groups, 1.4% and 3.0% of patients had appendicitis, respectively. The area under the ROC curve was 0.89 (95% confidence interval 0.87 to 0.92) for the pARC compared with 0.80 (95% confidence interval 0.77 to 0.82) for the PAS.

CONCLUSION

The pARC accurately assessed appendicitis risk for children aged 5 years and older in community EDs and the pARC outperformed the PAS.

Uptake and safety of hepatitis A vaccination during pregnancy: A Vaccine Safety Datalink study

INTRODUCTION

Infection with hepatitis A virus (HAV) during pregnancy, although uncommon, is associated with gestational complications and pre-term labor. Hepatitis A vaccine (HepA) is recommended for anyone at increased risk for contracting hepatitis A, including women at risk who are also pregnant. Limited data are available on the safety of maternal HepA vaccination.

OBJECTIVES

Assess the frequency of maternal HepA receipt and evaluate the potential association between maternal vaccination and pre-specified maternal and infant safety outcomes.

METHODS

A retrospective cohort of pregnancies in the Vaccine Safety Datalink (VSD) resulting in live births from 2004 through 2015 was included. Pregnancies with HepA exposure were compared to those with other vaccine exposures, and to those with no vaccine exposures. Risk factors for contracting hepatitis A were identified up to one-year prior to or during the pregnancy using ICD-9 codes. Maternal and fetal adverse events were evaluated according to maternal HepA exposure status. Adjusted odds ratio (OR) were used to describe the association.

RESULTS

Among 666,233 pregnancies in the study period, HepA was administered at a rate of 1.7 per 1000 (n = 1140), most commonly within the first six weeks of pregnancy. Less than 3% of those exposed to HepA during pregnancy had an ICD-confirmed risk factor. There were no significant associations between HepA exposure during pregnancy and gestational hypertension, gestational diabetes, pre-eclampsia/eclampsia, cesarean delivery, pre-term delivery, and low birthweight. There was a statistically significant association between HepA exposure during pregnancy and small-for-gestational age (SGA) infants (aOR 1.32, [95% CI 1.09, 1.60], p = 0.004).

CONCLUSIONS

The rate of maternal HepA vaccination was low and rarely due to documented risk factors for vaccination. HepA vaccination during pregnancy was not associated with an increased risk for a range of adverse events examined among pregnancies resulting in live births, but an identified association between maternal HepA and SGA infant outcomes, while likely due to unmeasured confounding, warrants further exploration.

Safety of guidelines recommending live attenuated influenza vaccine for routine use in children and adolescents with asthma

OBJECTIVE

Evaluate whether a guideline recommending Live Attenuated Influenza Vaccine (LAIV) for children 2 years and older with asthma increased risks for lower respiratory events (LREs), within 21 or 42 days of vaccination, as compared to standard guidelines to administer Inactivated Influenza Vaccine (IIV) in children with asthma.

METHODS

This was a pre/post guideline retrospective cohort study of children ages 2-17 years with asthma and receiving one or more influenza vaccines in two large medical groups from 2007 to 2016. Both groups recommended IIV in the pre-period; in 2010, one group implemented a guideline recommending LAIV for all children, including those with asthma. Main outcomes were medically attended LREs within 21 and 42 days after influenza immunization. Analysis used a generalized estimating equation regression to estimate the ratio of rate ratios (RORs) comparing pre/post events between LAIV guideline and control group.

RESULTS

The cohort included 7851 influenza vaccinations in 4771 children with asthma. Among patients in the LAIV guideline group, the proportion receiving LAIV increased from 23% to 68% post-guideline implementation, versus an increase from 7 to 11% in the control group. Age and baseline asthma severity adjusted ROR showed no increase in LREs, primarily asthma exacerbations, following implementation of the LAIV guideline: overall aROR (95% Confidence Interval): 0.74 (0.43-1.29) for LRE within 21 days of vaccination, 0.77 (0.53-1.14) for LRE within 42 days of vaccination. For the subset of children ages 2-4 years aROR: 0.92 (0.34-2.53) for LRE within 21 days of vaccination and 0.94 (0.49-1.82) for LRE within 42 days of vaccination; for children 5-18 years aROR (95% CI): 0.58 (0.26-1.30) for LRE within 21 days of vaccination and 0.67 (0.37-1.23) for LRE within 42 days.

CONCLUSION

In a large cohort of children with asthma, a guideline recommending LAIV rather than IIV did not increase LREs following vaccination.

HSR19-105: The Role of Chemotherapy in Elderly Colorectal Cancer Survivors: An Observational Study

Background: Older patients diagnosed with colorectal cancer are not routinely included in clinical trials and are frequently treated with less aggressive chemotherapy. To identify factors associated with treatment initiation in older adults, we conducted an observational study of patients diagnosed with stage I–IV colon or rectal cancer at 65 years and older between 2010 and 2014 across 6 integrated health care systems. Methods: Data were obtained from cancer registries based on chart abstraction and medical records. Time from diagnosis to surgery, chemotherapy, and radiation was measured in weeks and censored when disenrollment, death, or the end of the study period occurred. We assessed patient factors associated with time to chemotherapy initiation using survival analysis methods. Results: Among 8,088 patients diagnosed after the age of 65 with colon cancer, the mean age at diagnosis was 76 years (SD 7.7), 4,150 (51%) were female, and 34% were stage 3 or greater. More than half, 55% (n=4,434) of colon cancers were right-sided (RCC), 23% (n=1833) were left-sided (LCC), and 19% (n=1,559) were rectal cancers. Two-thirds (n=5,201) had moderately differentiated disease. Most (57%) received surgery within 4 weeks and 89% within 6 months of diagnosis (median, 3.4 weeks). At 6 months following diagnosis, 33% of patients had received chemotherapy, and only 4% received radiation. Factors associated with the receipt of chemotherapy were assessed in a multivariable survival model that included age, gender, stage, and site. Patients of older age were less likely to receive chemotherapy (HR, 0.49; 95%CI, 0.45–.53 for 75–79 vs 65–69 years), and more likely for advanced stage, and rectal site. No difference was observed between men and women. Refusal of chemotherapy was reported for only 6% of patients and was associated with age, stage, and site. Six month mortality was 13.3%. Conclusions: Factors associated with the receipt of treatment among older cancer survivors are similar to those in the general population.