Vaccination Timeliness Among US Children Aged 0-19 Months, National Immunization Survey-Child 2011-2021.

Importance: Delays in receiving vaccinations lead to greater vaccine-preventable disease risk. Timeliness of receipt of recommended vaccinations is not routinely tracked in the US, either overall or for populations that have known barriers to accessing routine health care, including lower-income families and children. Objective: To measure vaccination timeliness among US children aged 0 to 19 months, overall and by socioeconomic indicators. Design, Setting, and Participants: This serial, cross-sectional study analyzed nationally representative data from the 2011 to 2021 National Immunization Survey-Child (NIS-Child), an annual survey of parents, with immunization histories collected from clinicians administering vaccines. The 2020 and 2021 surveys largely reflected vaccinations in the US before the COVID-19 pandemic. Study participants included US children surveyed at ages 19 to 35 months. Data were analyzed from January to August 2023. Exposure: Survey year. Main Outcomes and Measures: The primary outcomes were average days undervaccinated (ADU) and percentage of children who received all vaccine doses on time (ie, 0 days undervaccinated) for the combined 7-vaccine series up to age 19 months. The mean adjusted annual change in on-time vaccination by socioeconomic indicators was calculated by use of multivariable log-linked binomial regression models. Results: The surveys included 179 154 children (92 248 boys [51.2%]); 74 479 (31.4%, weighted) lived above the federal poverty level with more than $75 000 in annual family income, 58 961 (32.4%) lived at or above the poverty level with $75 000 or less in annual family income, and 39 564 (30.2%) lived below the poverty level. Overall, the median (IQR) ADU for the combined 7-vaccine series in the US decreased from 22.3 (0.4-71.5) days in the 2011 survey to 11.9 (0.0-55.5) days in the 2021 survey. The prevalence of on-time receipt of the combined 7-vaccine series increased from 22.5% (95% CI, 21.4%-23.6%) to 35.6% (95% CI, 34.2%-37.0%). Although children with more than $75 000 in annual family income had a 4.6% (95% CI, 4.0%-5.2%) mean annual increase in on-time vaccination, the mean annual increase was 2.8% (95% CI, 2.0%-3.6%) for children living at or above the poverty level with $75 000 or less in annual family income and 2.0% (95% CI, 1.0%-3.0%) for children living below the poverty level. Conclusions and Relevance: In this cross-sectional study of NIS-Child data, improvements in vaccination timeliness were observed from the 2011 to the 2021 survey. However, widening disparities by socioeconomic indicators signal that increased efforts to facilitate timely vaccination among children in lower-income families are needed.

Systematic Review of Barriers to and Facilitators of Screening for Postpartum Depression at Well-Child Visits in the United States.

OBJECTIVE: To identify and evaluate barriers to and facilitators of screening for postpartum depression (PPD) during well-child visits in the United States. Additionally, to describe prior work on PPD screening tool evaluation and outcomes from PPD screenings conducted within the well-child setting. DATA SOURCES: A systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Five databases (Pub Med, PsycINFO, Web of Science, CINAHL, and Cochrane Library) were searched. STUDY SELECTION: Randomized controlled trials, case studies, cross-sectional studies, case-control studies, cohort studies, qualitative studies, and quasi-experimental studies conducted in the United States were included. The Standard Quality Assessment Criteria Tool (QualSyst) was used to assess the methodologic quality of each included study. DATA EXTRACTION: Sample, setting, methods, screening tools used, location of study setting, intervention, and salient findings were extracted and summarized for further analysis and synthesis. DATA SYNTHESIS: Quantitative studies were rated on 14 aspects, and qualitative studies were rated on 10 aspects, per QualSyst. Studies received a score of 2, 1, 0, or not applicable based on scoring criteria, with higher scores indicating greater methodologic quality. CONCLUSION: We found that barriers to PPD screening included concerns regarding time for screening, adequate training, and limited ability for referral. Facilitators of PPD screening included electronic prompts for providers, as well as tool availability and familiarity. Our results indicate that education and training about PPD screening in the pediatric setting are important next steps in addressing the rising concern of PPD in the United States.

Completion of multidose vaccine series in early childhood: current challenges and opportunities.

PURPOSE OF REVIEW: Completion of all doses in multidose vaccine series provides optimal protection against preventable infectious diseases. In this review, we describe clinical and public health implications of multidose vaccine series noncompletion, including current challenges to ensuring children receive all recommended vaccinations. We then highlight actionable steps toward achieving early childhood immunization goals. RECENT FINDINGS: Although coverage levels are high for most early childhood vaccinations, rates of completion are lower for vaccinations that require multiple doses. Recent research has shown that lower family socioeconomic status, a lack of health insurance coverage, having multiple children in the household, and moving across state lines are associated with children failing to complete multidose vaccine series. These findings provide contextual evidence to support that practical challenges to accessing immunization services are impediments to completion of multidose series. Strategies, including reminder/recall, use of centralized immunization information systems, and clinician prompts, have been shown to increase immunization rates. Re-investing in these effective interventions and modernizing the public health infrastructure can facilitate multidose vaccine series completion. SUMMARY: Completion of multidose vaccine series is a challenge for immunization service delivery. Increased efforts are needed to address remaining barriers and improve vaccination coverage in the United States.

Challenges in Accessing Mental Health Care during Pregnancy and Postpartum in Rural Montana.

PURPOSE: Postpartum depression is a well-known maternal health care concern. For women using substances or experiencing underlying mental health conditions, incidence of postpartum depression is higher than that of the general population. The purpose of this study was to identify barriers and facilitators associated with seeking mental health care among women with substance use disorder or mental health concerns. STUDY DESIGN AND METHODS: Qualitative methods using interviews were conducted via the narrative inquiry approach. Women receiving care at a clinic in rural Montana and reporting substance use or mental health concerns were referred to the research team by the care manager. Participants were at least 18 years of age, English speaking, and pregnant or within 12 months postpartum at time of referral. RESULTS: Twenty-five women met inclusion criteria and were referred for potential study participation. Seven women were interviewed. Four themes on family history, stigmatization, lack of postpartum depression awareness, and isolation were identified. CLINICAL IMPLICATIONS: Our findings provide a better understanding of barriers and facilitators to seeking mental health care during pregnancy and postpartum among women living in rural areas with mental health concerns or perinatal substance use. An environment where opportunities for women to receive mental health care in a location that is free of stigma and judgment, while understanding the effects of familial trauma and limited or inconsistent social support, is essential to promote optimal outcomes.

Identification of Spatial Clusters of Undervaccination Patterns Among Children Aged <24 Months Using Immunization Information System Data, Montana, 2015-2019.

OBJECTIVE: Spatial clustering of undervaccination leads to increased risk of vaccine-preventable diseases. We identified spatial clustering of undervaccination patterns among children aged <24 months in Montana. METHODS: We used Montana's immunization information system data to analyze deidentified vaccination records of children aged <24 months born from January 2015 through November 2017. We measured 3 outcomes that were not mutually exclusive: not completing the combined 7-vaccine series by age 24 months, having an undervaccination pattern indicative of parental hesitancy, and having an undervaccination pattern indicative of structural barriers to timely vaccination. Using geomasked residential addresses, we conducted separate Bernoulli spatial scans with a randomization P < .01 to identify spatial clusters consisting of ≥100 children for each outcome and calculated the relative risk of having the undervaccination pattern inside versus outside the cluster. RESULTS: Of 31 201 children aged <24 months included in our study, 11 712 (37.5%) had not completed the combined 7-vaccine series by age 24 months, and we identified 5 spatial clusters of this outcome across Montana. We identified 4 clusters of undervaccination patterns indicative of parental vaccine hesitancy, all in western Montana. The cluster with the largest relative risk (2.3) had a radius of 23.7 kilometers (n = 762 children, P < .001). We also identified 4 clusters of undervaccination patterns indicative of structural barriers, with 3 of the largest clusters in eastern Montana. CONCLUSION: In Montana, different strategies to increase routine and timely childhood vaccination are needed in distinct areas of this large and predominantly rural state. Immunization information system data can pinpoint areas where interventions to increase vaccination uptake are needed.

Failure to Complete Multidose Vaccine Series in Early Childhood.

BACKGROUND: Most early childhood immunizations require 3 to 4 doses to achieve optimal protection. Our objective was to identify factors associated with starting but not completing multidose vaccine series. METHODS: Using 2019 National Immunization Survey-Child data, US children ages 19 to 35 months were classified in 1 of 3 vaccination patterns: (1) completed the combined 7-vaccine series, (2) did not initiate ≥1 of the 7 vaccine series, or (3) initiated all series, but did not complete ≥1 multidose series. Associations between sociodemographic factors and vaccination pattern were evaluated using multivariable log-linked binomial regression. Analyses accounted for the survey's stratified design and complex weighting. RESULTS: Among 16 365 children, 72.9% completed the combined 7-vaccine series, 9.9% did not initiate ≥1 series, and 17.2% initiated, but did not complete ≥1 multidose series. Approximately 8.4% of children needed only 1 additional vaccine dose from 1 of the 5 multidose series to complete the combined 7-vaccine series. The strongest associations with starting but not completing multidose vaccine series were moving across state lines (adjusted prevalence ratio [aPR] = 1.45, 95% confidence interval [CI]: 1.18-1.79), number of children in the household (2 to 3: aPR = 1.29, 95% CI: 1.05-1.58; 4 or more: aPR = 1.68, 95% CI: 1.30-2.18), and lack of insurance coverage (aPR = 2.03, 95% CI: 1.42-2.91). CONCLUSIONS: More than 1 in 6 US children initiated but did not complete all doses in multidose vaccine series, suggesting children experienced structural barriers to vaccination. Increased focus on strategies to encourage multidose series completion is needed to optimize protection from preventable diseases and achieve vaccination coverage goals.

Nurses' perceptions, experiences, and practices regarding human papillomavirus vaccination: results from a cross-sectional survey in Montana.

BACKGROUND: Nationally, much of the focus on improving human papillomavirus (HPV) vaccine uptake has been on effective strategies that physicians use to promote vaccination. However, in large, predominately rural states like Montana, nurses and medical assistants play critical roles in immunization services delivery, and their viewpoints are imperative in designing strategies to increase vaccination rates. We conducted a cross-sectional, descriptive study to determine nurses' perceptions, experiences, and practices regarding human papillomavirus vaccination in a rural and medically underserved region of the United States. METHODS: We designed, pilot-tested, and disseminated an online survey instrument to nurses and medical assistants working in clinics participating in the Vaccines for Children program in Montana. The online surveys were administered from November 2020 to March 2021. Survey questions focused on clinic vaccination practices, respondents' perceptions of the HPV vaccine, perceived barriers to vaccine uptake, and general opinions on potential strategies to improve HPV vaccination rates. RESULTS: We analyzed data from 227 respondents. Overall, 90% of nurses strongly agreed or agreed that the HPV vaccine is important and had confidence in the vaccine's safety. More nurses reported experiencing greater parental vaccine refusal or delay for male patients regardless of age. About 53.7% of nurses reported that their clinics had reminder/recall systems to encourage parents to bring their children for vaccination. Nurses identified misinformation from social media, infrequent wellness visits, and vaccine safety concerns as barriers to HPV vaccine uptake. CONCLUSIONS: Study findings identified several promising initiatives to accelerate vaccination in primarily rural states like Montana, including promoting widespread adoption of reminder/recall systems, training nurses in evidence-based techniques to provide strong vaccine recommendations, and leveraging social media to disseminate consistent messages about the HPV vaccine recommendations for both sexes and its role in cancer prevention.

Childhood Vaccination Practices and Parental Hesitancy Barriers in Rural and Urban Primary Care Settings.

The purpose of our study was to identify primary care providers' (PCPs') practices in promoting childhood vaccination and their perceptions regarding barriers to vaccination in a primarily rural state. In January-May 2022, we conducted a mail and online survey of PCPs across Montana (n = 829). The survey included modules on routine immunizations in children 0-2 years old and COVID-19 vaccination in children 5-17 years old. The survey response rate was 36% (298/829). We categorized PCPs as working in rural (n = 218) or urban areas (n = 80), based on Rural-Urban Commuting Area codes. We then compared responses between rural and urban PCPs using chi-square tests. Urban PCPs (90-94%, depending on vaccine) stocked routinely recommended vaccines more frequently than rural PCPs (71-84%), but stocked the COVID-19 vaccine less often than rural PCPs (44% vs. 71%, respectively, p < 0.001). A higher percentage of rural providers reported parental beliefs that vaccine-preventable diseases are not severe enough to warrant vaccination (48% vs. 31%, p = 0.01) and concerns that vaccination will weaken their child's immune system (29% vs. 6%, p < 0.001). More rural (74%) compared to urban (59%) PCPs identified a social media campaign from local health departments promoting early childhood vaccinations as an effective strategy to increase childhood vaccination rates (p = 0.01). We identified key differences in some childhood vaccination practices and barriers between rural and urban PCPs. Interventions to increase rural vaccination rates could include increasing the number of providers stocking all recommended vaccines, identifying strategies to address parents' concerns regarding vaccine necessity, and collaborations with public health departments.

Geographic proximity to immunization providers and vaccine series completion among children ages 0-24 months.

OBJECTIVES: In the U.S., vaccination coverage is lower in rural versus urban areas. Spatial accessibility to immunization services has been a suspected risk factor for undervaccination in rural children. Our objective was to identify whether geographic factors, including driving distance to immunization providers, were associated with completion of recommended childhood vaccinations. METHODS: We analyzed records from Montana's immunization information system for children born 2015-2017. Using geolocated address data, we calculated distance in road miles from children's residences to the nearest immunization provider. A multivariable log-linked binomial mixed model was used to identify factors associated with completion of the combined 7-vaccine series by age 24 months. RESULTS: Among 26,085 children, 16,503 (63.3%) completed the combined 7-vaccine series by age 24 months. Distance to the nearest immunization provider ranged from 0 to 81.0 miles (median = 1.7; IQR = 3.2), with the majority (92.1%) of children living within 10 miles of a provider. Long distances (>10 miles) to providers had modest associations with not completing the combined 7-vaccine series (adjusted prevalence ratio [aPR]: 0.97, 95% confidence interval [CI]: 0.96-0.99). After adjustment for other factors, children living in rural areas (measured by rural-urban commuting area) were significantly less likely to have completed the combined 7-vaccine series than children in metropolitan areas (aPR: 0.88, 95% CI: 0.85-0.92). CONCLUSIONS: Long travel distances do not appear to be a major barrier to childhood vaccination in Montana. Other challenges, including limited resources for clinic-based strategies to promote timely vaccination and parental vaccine hesitancy, may have greater influence on rural childhood vaccination.

Beyond Vaccination Coverage: Population-Based Measurement of Early Childhood Immunization Schedule Adherence.

The immunization schedule recommended by the U.S. Advisory Committee on Immunization Practices (ACIP) provides a structure for how 10 different vaccine series should be administered to children in the first 18 months of life. Progress toward US early childhood immunization goals has largely focused on measuring vaccination coverage at age 24 months. However, standard vaccination coverage measures do not reflect whether children received vaccine doses by recommended ages, or whether vaccines were given concomitantly, per the schedule. In this paper, we describe innovations in population-level measurement of immunization schedule adherence through quantifying vaccination timeliness and undervaccination patterns. Measuring vaccination timeliness involves comparing when children received vaccine doses relative to ACIP age recommendations. To assess undervaccination patterns, children's vaccination histories are analyzed to determine whether they were vaccinated consistent with the ACIP schedule. Some patterns, such as spreading out vaccines across visits, are indicative of parental hesitancy. Other patterns, such as starting all recommended series but missing doses, are largely indicative of other immunization services delivery challenges. Since 2003, at least 12 studies have used National Immunization Survey-Child, immunization information system, or integrated health plan data to measure vaccination timeliness or undervaccination patterns at national or state levels. Moving forward, these novel measures can be leveraged for population-based surveillance of vaccine confidence, and for distinguishing undervaccination due to parental vaccine hesitancy from undervaccination due to other causes. Broader adoption of these measures can facilitate identification of targeted strategies for improving timely and routine early childhood vaccination uptake across the United States.

Improving pediatric COVID-19 vaccine uptake using an mHealth tool (MoVeUP): a randomized, controlled trial.

Background: Coronavirus disease 2019 (COVID-19) vaccines demonstrate excellent effectiveness against infection, severe disease, and death. However, pediatric COVID-19 vaccination rates lag among individuals from rural and other medically underserved communities. The research objective of the current protocol is to determine the effectiveness of a vaccine communication mobile health (mHealth) application (app) on parental decisions to vaccinate their children against COVID-19. Methods: Custodial parents/caregivers with ≥1 child eligible for COVID-19 vaccination who have not yet received the vaccine will be randomized to download one of two mHealth apps. The intervention app will address logistical and motivational barriers to pediatric COVID-19 vaccination. Participants will receive eight weekly push notifications followed by two monthly push notifications (cues to action) regarding vaccinating their child. Through branching logic, users will access customized content based on their locality, degree of rurality-urbanicity, primary language (English/Spanish), race/ethnicity, and child's age to address COVID-19 vaccine knowledge and confidence gaps. The control app will provide push notifications and information on general pediatric health and infection prevention and mitigation strategies based on recommendations from the American Academy of Pediatrics (AAP) and the Centers for Disease Control and Prevention (CDC). The primary outcome is the proportion of children who complete COVID-19 vaccination series. Secondary outcomes include the proportion of children who receive ≥1 dose of COVID-19 vaccine and changes in parent/caregiver scores from baseline to immediately post-intervention on the modified WHO SAGE Vaccine Hesitancy Scale adapted for the COVID-19 vaccine. Discussion: The COVID-19 pandemic inflicts disproportionate harm on individuals from underserved communities, including those in rural settings. Maximizing vaccine uptake in these communities will decrease infection rates, severe illness, and death. Given that most US families from these communities use smart phones, mHealth interventions hold the promise of broad uptake. Bundling multiple mHealth vaccine-uptake interventions into a single app may maximize the impact of deploying such a tool to increase COVID-19 vaccination. The new knowledge to be gained from this study will directly inform future efforts to increase COVID-19 vaccination rates across diverse settings and provide an evidentiary base for app-based vaccine communication tools that can be adapted to future vaccine-deployment efforts. Clinical Trials Registration: Name of the registry: clinicaltrials.gov Trial registration number: NCT05386355 Date of registration: May 23, 2022 URL of trial registry record: https://clinicaltrials.gov/ct2/show/NCT05386355.

Improving pediatric COVID-19 vaccine uptake using an mHealth tool (MoVeUp): study protocol for a randomized, controlled trial.

BACKGROUND: Coronavirus disease 2019 (COVID-19) vaccines demonstrate excellent effectiveness against infection, severe disease, and death. However, pediatric COVID-19 vaccination rates lag among individuals from rural and other medically underserved communities. The research objective of the current protocol is to determine the effectiveness of a vaccine communication mobile health (mHealth) application (app) on parental decisions to vaccinate their children against COVID-19. METHODS: Custodial parents/caregivers with ≥ 1 child eligible for COVID-19 vaccination who have not yet received the vaccine will be randomized to download one of two mHealth apps. The intervention app will address logistical and motivational barriers to pediatric COVID-19 vaccination. Participants will receive eight weekly push notifications followed by two monthly push notifications (cues to action) regarding vaccinating their child. Through branching logic, users will access customized content based on their locality, degree of rurality-urbanicity, primary language (English/Spanish), race/ethnicity, and child's age to address COVID-19 vaccine knowledge and confidence gaps. The control app will provide push notifications and information on general pediatric health and infection prevention and mitigation strategies based on recommendations from the American Academy of Pediatrics (AAP) and the Centers for Disease Control and Prevention (CDC). The primary outcome is the proportion of children who complete COVID-19 vaccination series. Secondary outcomes include the proportion of children who receive ≥ 1 dose of COVID-19 vaccine and changes in parent/caregiver scores from baseline to immediately post-intervention on the modified WHO SAGE Vaccine Hesitancy Scale adapted for the COVID-19 vaccine. DISCUSSION: The COVID-19 pandemic inflicts disproportionate harm on individuals from underserved communities, including those in rural settings. Maximizing vaccine uptake in these communities will decrease infection rates, severe illness, and death. Given that most US families from these communities use smart phones, mHealth interventions hold the promise of broad uptake. Bundling multiple mHealth vaccine uptake interventions into a single app may maximize the impact of deploying such a tool to increase COVID-19 vaccination. The new knowledge to be gained from this study will directly inform future efforts to increase COVID-19 vaccination rates across diverse settings and provide an evidentiary base for app-based vaccine communication tools that can be adapted to future vaccine-deployment efforts. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov NCT05386355 . Registered on May 23, 2022.

Evaluating vaccination coverage and timeliness in American Indian/Alaska Native and non-Hispanic White children using state immunization information system data, 2015-2017.

Comprehensive estimates of vaccination coverage and timeliness of vaccine receipt among American Indian/Alaska Native (AI/AN) children in the United States are lacking. This study's objectives were to quantify vaccination coverage and timeliness, as well as the proportion of children with specific undervaccination patterns, among AI/AN and non-Hispanic White (NHW) children ages 0-24 months in Montana, a large and primarily rural U.S. state. Data from Montana's immunization information system (IIS) for children born 2015-2017 were used to calculate days undervaccinated for all doses of seven recommended vaccine series. After stratifying by race/ethnicity, up-to-date coverage at key milestone ages and the proportion of children demonstrating specific patterns of undervaccination were reported. Among n = 3,630 AI/AN children, only 23.1% received all recommended vaccine doses on-time (i.e., zero days undervaccinated), compared to 40.4% of n = 18,022 NHW children (chi-square p < 0.001). A greater proportion of AI/AN children were delayed at each milestone age, resulting in lower overall combined 7-vaccine series completion, by age 24 months (AI/AN: 56.6%, NHW: 64.3%, chi-square p < 0.001). As compared with NHW children, a higher proportion of AI/AN children had undervaccination patterns suggestive of structural barriers to accessing immunization services and delayed starts to vaccination. More than three out of four AI/AN children experienced delays in vaccination or were missing doses needed to complete recommended vaccine series. Interventions to ensure on-time initiation of vaccine series at age 2 months, as well initiatives to encourage completion of multi-dose vaccine series, are needed to reduce immunization disparities and increase vaccination coverage among AI/AN children in Montana.

Barriers to and facilitators of early childhood immunization in rural areas of the United States: A systematic review of the literature.

Early childhood vaccination rates are lower in rural areas of the U.S. compared with suburban and urban areas. Our aim was to identify barriers to and facilitators of early childhood immunization in rural U.S. communities. We completed a systematic review of original research conducted in the U.S. between January 1, 2000-July 25, 2021. We searched PubMed, Cumulative Index for Nursing and Allied Health Literature, and Web of Science. We included studies that examined barriers to and facilitators of routine immunizations in children <36 months old in rural areas. Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, we reported studies' methodologies and targeted populations, definitions of rurality, and common themes across studies that reflected barriers to or facilitators of vaccination. Ultimately, 17 papers met inclusion criteria for review. The majority of studies (10/17) were conducted within one U.S. state, and the same number (10/17) were conducted prior to 2005. Facilitators of vaccine uptake in rural communities identified across studies included reminder/recall systems and parents' relationships with providers. Parental hesitancy, negative clinic experiences, referrals outside of primary care settings, and distance to providers were identified as barriers to vaccination in rural settings. This review revealed a limited scope of evidence on barriers to and facilitators of early childhood immunization in rural communities. More investigations of the causes of low vaccine coverage and the effectiveness of interventions for increasing vaccine uptake are urgently needed in rural pediatric populations to address persistent rural-urban immunization disparities.

Missed opportunities for human papillomavirus vaccine series initiation in a large, rural U.S. state.

Human papillomavirus (HPV) vaccination rates are lower in rural versus urban areas of the United States. Our objective was to identify the types of vaccination clinic settings where missed opportunities for HPV vaccine series initiation most frequently occurred in Montana, a large, primary rural U.S. state. We analyzed a limited dataset from Montana's immunization information system for adolescents who turned 11 years old in 2014-2017. Vaccination visits where the HPV vaccine was due but not administered were missed opportunities. We compared missed opportunities across six types of clinic settings, and calculated adjusted relative risks (RR) using a generalized estimating equation model. Among n = 47,622 adolescents, 53.9% of 71,447 vaccination visits were missed opportunities. After adjusting for sex, age, and rurality of clinic location, receiving vaccines in public health departments was significantly associated with higher risk of missed opportunities (aRR = 1.25, 95% confidence interval = 1.22-1.27, vs. private clinics). Receipt of vaccines in Indian Health Services and Tribal clinics was associated with fewer missed opportunities (aRR = 0.72, 95% CI: 0.69-0.75, vs. private clinics). Our results indicate the need for interventions to promote HPV vaccine uptake in public health departments, which are a critical source of immunization services in rural and medically underserved areas of the U.S.

Vaccine timeliness and prevalence of undervaccination patterns in children ages 0-19 months, U.S., National Immunization Survey-Child 2017.

OBJECTIVES: Typically, early childhood vaccination coverage in the U.S. is measured as the proportion of children by age 24 months who completed recommended vaccine series. However, these measures do not reflect whether vaccine doses were received at the ages recommended by the U.S. Advisory Committee on Immunization Practices, or whether children received vaccines concomitantly, per the ACIP recommended schedule. This study's objective was to quantify vaccine timeliness and prevalence of specific patterns of undervaccination in U.S. children ages 0-19 months. METHODS: Using 2017 National Immunization Survey-Child data, we calculated days undervaccinated for the combined 7-vaccine series and distinguished undervaccination patterns indicative of parental vaccine hesitancy, such as spreading out vaccines across visits ("shot-limiting") or starting some but not all recommended vaccine series ("selective vaccination"), from other non-hesitancy patterns, such as missing final vaccine doses or receiving all doses, with some or all late. We measured associations between demographic, socioeconomic and other characteristics with undervaccination patterns using multivariable log-linked binomial regression. Analyses accounted for the complex survey design. RESULTS: Among n = 15,333 U.S. children, only 41.2% received all recommended vaccine doses on-time by age 19 months. Approximately 20.9% of children had an undervaccination pattern suggestive of parental vaccine hesitancy, and 36.2% had other undervaccination non-hesitancy patterns. Uninsured children and those with lower levels of maternal education were more likely to exhibit undervaccination patterns suggestive of parental hesitancy. Lower levels of maternal education were also associated with other non-hesitancy undervaccination patterns. CONCLUSIONS: More than half of children in the U.S. are undervaccinated at some point by 19 months of age. Ongoing assessment of vaccine timeliness and immunization schedule adherence could facilitate timely and targeted public health interventions in populations with high levels of undervaccination.

Barriers to healthcare access among U.S. adults with mental health challenges: A population-based study.

BACKGROUND: Having sufficient healthcare access helps individuals proactively manage their health challenges, leading to positive long-term health outcomes. In the U.S., healthcare access is a public health issue as many Americans lack the physical or financial resources to receive the healthcare services they need. Mental healthcare is especially difficult due to lingering social stigmas and scarcity of services. Subsequently, those with mental health impairment tend to be complex patients, which may convolute delivery of services. OBJECTIVE: To quantify the prevalence of barriers to healthcare access among U.S. adults with and without mental health challenges (MHC) and evaluate the relationship between MHC and no usual source of care (NUSC). METHODS: A cross-sectional study was conducted with data from the 2017-2018 National Health Interview Survey. MHC was categorized into three levels: no (NPD), moderate (MPD) and severe (SPD) psychological distress. Eight barriers were quantified; one was used as the primary outcome: NUSC. Multivariable logistic regression was used to quantify associations between these characteristics. RESULTS: The sample included 50,103 adults. Most reported at least one barrier to healthcare access (95.6%) while 13.3% reported NUSC. For each barrier, rates were highest among those with SPD and lowest for those with NPD. However, in the multivariable model, SPD and MPD were not associated with NUSC (OR, 0.92; 95% CI, 0.83-1.01; 0.88; 0.73-1.07). Male sex (1.92; 1.78-2.06), Hispanic race/ethnicity (1.59; 1.42-1.77), and worry to afford emergent (1.38; 1.26-150) or normal (1.60; 1.46-1.76) healthcare were associated with NUSC. Having a current partner (0.88; 0.80-0.96), dependent(s) (0.77; 0.70-0.85) and paid sick leave (0.60; 0.56-0.65) were protective. CONCLUSIONS: The most prevalent barriers to healthcare access link to issues with affordability, and MHC exist more often when any barrier is reported. More work is needed to understand the acuity of burden as other social and environmental factors may hold effect.

Sensitivity analyses of unmeasured and partially-measured confounders using multiple imputation in a vaccine safety study.

PURPOSE: Sensitivity analyses have played an important role in pharmacoepidemiology studies using electronic health records data. Despite the existence of quantitative bias analysis in pharmacoepidemiologic studies, simultaneously adjusting for unmeasured and partially measured confounders is challenging in vaccine safety studies. Our objective was to develop a flexible approach for conducting sensitivity analyses of unmeasured and partially-measured confounders concurrently for a vaccine safety study. METHODS: We derived conditional probabilities for an unmeasured confounder based on bias parameters, used these conditional probabilities and Monte Carlo simulations to impute the unmeasured confounder, and re-constructed the analytic datasets as if the unmeasured confounder had been observed. We simultaneously imputed a partially measured confounder using a prediction model. We considered unmeasured breastfeeding and partially measured family history of Type 1 diabetes (T1DM) in a study examining the association between exposure to rotavirus vaccination and T1DM. RESULTS: Before sensitivity analyses, the hazard ratios (HR) were 1.50 (95% CI, 0.81-2.77) for those partially exposed and 1.03 (95% CI, 0.62-1.72) for those fully exposed with unexposed children as the referent group. When breastfeeding and family history of T1DM were adjusted, the HR was 1.55 (95% CI, 0.84-2.87) for the partially exposed group; the HR was 0.98 (95% CI, 0.58-1.63) for the fully exposed group. CONCLUSIONS: We conclude that adjusting for unmeasured breastfeeding and partially measured family history of T1DM did not alter the conclusion that there was no evidence of association between rotavirus vaccination and developing T1DM. This novel approach allows for simultaneous adjustment for multiple unmeasured and partially-measured confounders.

Timeliness of Early Childhood Vaccinations and Undervaccination Patterns in Montana.

INTRODUCTION: Early childhood vaccination rates are lower in rural areas than those in urban areas of the U.S. This study's objective is to quantify vaccine timeliness and the prevalence of undervaccination patterns in Montana and to measure the associations between timeliness and series completion by age 24 months. METHODS: Using records from January 2015 to November 2019 in Montana's centralized immunization information system, days undervaccinated were calculated for the combined 7-vaccine series. Undervaccination patterns indicative of certain barriers to vaccination, including parental vaccine hesitancy, were identified. Using multivariable log-linked binomial regression, the association between timing of vaccine delay and not completing the combined 7-vaccine series by age 24 months was assessed. Analyses were conducted in March 2020-August 2020. RESULTS: Among 31,422 children, 38.0% received all vaccine doses on time; 24.3% received all doses, but some were received late; and 37.7% had not completed the combined 7-vaccine series. Approximately 18.7% had an undervaccination pattern suggestive of parental vaccine hesitancy, and 19.7% started all series but were missing doses needed for multidose series completion. Although falling behind on vaccinations at any age was associated with failing to complete the combined 7-vaccine series, being late at age 12-15 months had the strongest association (adjusted prevalence ratio=3.73, 95% CI=3.56, 3.91) compared with being on time at age 12-15 months. CONCLUSIONS: Fewer than 2 in 5 Montana children were fully vaccinated on time for the combined 7-vaccine series. To increase vaccination rates, initiatives to increase vaccine confidence and remind parents to complete vaccine series are needed.