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.

Human Papillomavirus Vaccine Effectiveness Against Incident Genital Warts Among Female Health-Plan Enrollees, United States.

We examined the effectiveness of human papillomavirus vaccination by dose number and spacing against incident genital warts in a cohort of 64,517 female health-plan enrollees in the United States during 2006-2012. Eligible recipients were classified into groups by regimen: 0, 1, 2 (<6 months apart), 2 (≥6 months apart), or 3 doses. They were followed until a genital wart diagnosis, loss to follow-up, or the end of study. Propensity score weights were used to balance baseline differences across groups. To account for latent genital warts before vaccination, we applied 6- and 12-month buffer periods from last and first vaccine dose, respectively. Incidence rates and hazard ratios were calculated using Poisson regression and Cox models. The propensity score-weighted incidence rate per 100,000 person-years was 762 among unvaccinated participants. Using 6- and 12-month buffer periods, respectively, incidence rates were 641 and 257 for 1 dose, 760 and 577 for the 2-dose (<6-month interval) regimen, 313 and 194 for the 2-dose (≥6-month interval) regimen, and 199 and 162 among 3-dose vaccinees; vaccine effectiveness was 68% and 76% for the 2-dose (≥6-month interval) regimen and 77% and 80% in 3-dose vaccinees compared with unvaccinated participants. Vaccine effectiveness was not significant among vaccinees receiving 1-dose and 2-dose (<6-month interval) regimens compared with unvaccinated participants. Our findings contribute to a better understanding of the real-world effectiveness of HPV vaccination.

Predictors of Breastfeeding Initiation and Maintenance in an Integrated Healthcare Setting.

BACKGROUND: The American Academy of Pediatrics recommends exclusive breastfeeding to age 6 months. Although breastfeeding rates in the United States have been increasing over time, further improvements are needed to meet Healthy People 2020 targets. Research aim: This study examined predictors of breastfeeding initiation and maintenance among a population of insured pregnant women. METHODS: Participants were 1,149 pregnant women enrolled in the Pregnancy and Influenza Project in two Kaiser Permanente regions in 2010-2011. Data were collected through interviews at enrollment and 1 month and 6 months postpartum and through participants' electronic medical records. RESULTS: Nearly all (99%) women reported initiating breastfeeding. Rates of exclusive breastfeeding were 70% and 54% at 1 month and 6 months, respectively; an additional 22% and 23% of women reported supplementing breastfeeding with formula. Of the women who supplemented, the mean ( SD) infant age at formula introduction was 53 (62) days. Of those who had stopped breastfeeding, the mean ( SD) infant age at cessation was 85 (59) days. Higher maternal education level, better maternal self-rated health, prenatal folic acid use, absence of chronic medical conditions, and infant full-term birth were significantly associated with breastfeeding maintenance. CONCLUSION: Although rates of breastfeeding in this population were higher than national rates, a significant number of women stopped breastfeeding or introduced formula earlier than recommended. Two to 3 months postpartum may be a critical period warranting additional encouragement or intervention by healthcare providers. Mothers' education attainment, maternal health factors, and gestational age at delivery may predict likelihood of breastfeeding maintenance.

Implementing a Multipartner HPV Vaccination Assessment and Feedback Intervention in an Integrated Health System.

CONTEXT: Human papillomavirus (HPV) vaccine initiation rates are persistently lower than rates for other adolescent-recommended vaccines. Assessment and feedback interventions are a recommended strategy for improving vaccination rates. OBJECTIVE: To provide a guide for implementing a multipartner intervention to increase HPV vaccine initiation rates. SETTING: Nine primary care facilities within the Kaiser Permanente Northwest (KPNW) health care system. INTERVENTION: In 2015-2016, we implemented a system-wide assessment and feedback intervention to promote HPV vaccination. In partnership with the Centers for Disease Control and Prevention, the Oregon Immunization Program, and KPNW's leadership, we developed an education session combining information on HPV infection, parental communication strategies, and facility-specific coverage data. RESULTS: Twelve months postintervention, HPV dose 1 vaccination coverage increased from 71% to 72% among females and from 65% to 68% among males. CONCLUSIONS: A collaborative approach was critical to engaging leadership and enlisting support from providers and to developing appropriate materials for clinical audiences. Information provided here can be used as a guide for conducting assessment and feedback interventions focused on HPV vaccination initiation.

Uptake, coverage, and completion of quadrivalent human papillomavirus vaccine in the vaccine safety Datalink, July 2006-June 2011.

PURPOSE: The Advisory Committee on Immunization Practices recommended quadrivalent human papillomavirus vaccine (HPV4) for use in females in June 2006 and in males in October 2009. The objective of our study was to describe HPV4 uptake, single-dose coverage, and completion of the three-dose series among those 9-26 years of age, after the respective female and male vaccine licensures through June 2011. METHODS: The study population included members of eight managed care organizations participating in the Vaccine Safety Datalink; we abstracted demographic and comprehensive vaccine information from electronic health records. RESULTS: We found one-dose coverage increasing throughout the study period, to a high of 37.7% among females and 1.3% among males in June 2011. Among those receiving at least one HPV4 dose, three-dose series completion was 42% for females and 30.2% for males. CONCLUSIONS: Our results demonstrate low initiation and completion of the HPV4 series among those recommended to receive the vaccine. Although consistent with previous studies, these results highlight the continued need to develop, implement, and monitor strategies to increase HPV4 vaccine initiation and completion in younger adolescents to achieve maximum impact in reducing the burden of cervical cancer and other HPV-related diseases.

Prevalence of HPV types in cervical specimens from an integrated healthcare delivery system: baseline assessment to measure HPV vaccine impact.

PURPOSE: Two human papillomavirus (HPV) vaccines are available to prevent cervical cancer. One early measure of HPV vaccine impact would be a reduction in vaccine-related HPV types (HPV 6, 11, 16, or 18, or HPV 16, 18) in cervical samples from young women. We aimed to assess feasibility of specimen collection and baseline HPV prevalence in an integrated healthcare delivery system. METHODS: Residual cervical specimens collected during routine cervical cancer screening (2006-2008) were retained consecutively from eligible females aged 11-29 years, stratified by age group. Specimens were evaluated for 37 HPV genotypes using the Roche Linear Array assay. RESULTS: Of 10,124 specimens submitted, 10,103 (99 %) were adequate for HPV testing. Prevalence of HPV 6, 11, 16, or 18 genotype was 11.4 % overall and was the highest in the youngest age group (18.1 % in the 11-19-year-olds, 12.5 % in the 20-24-year-olds, and 7.0 % in the 25-29-year-olds). CONCLUSIONS: HPV types 6, 11, 16, or 18 prevalence could be measured over time to assess early HPV vaccine impact using residual specimens from an integrated healthcare delivery system, particularly if sampling focused on young women.

A population-based cohort study of undervaccination in 8 managed care organizations across the United States.

OBJECTIVES To examine patterns and trends of undervaccination in children aged 2 to 24 months and to compare health care utilization rates between undervaccinated and age-appropriately vaccinated children. DESIGN Retrospective matched cohort study. SETTING Eight managed care organizations of the Vaccine Safety Datalink. PARTICIPANTS Children born between 2004 and 2008. MAIN EXPOSURE Immunization records were used to calculate the average number of days undervaccinated. Two matched cohorts were created: 1 with children who were undervaccinated for any reason and 1 with children who were undervaccinated because of parental choice. For both cohorts, undervaccinated children were matched to age-appropriately vaccinated children by birth date, managed care organization, and sex. MAIN OUTCOME MEASURES Rates of undervaccination, specific patterns of undervaccination, and health care utilization rates. RESULTS Of 323 247 children born between 2004 and 2008, 48.7% were undervaccinated for at least 1 day before age 24 months. The prevalence of undervaccination and specific patterns of undervaccination increased over time (P < .001). In a matched cohort analysis, undervaccinated children had lower outpatient visit rates compared with children who were age-appropriately vaccinated (incidence rate ratio [IRR], 0.89; 95% CI, 0.89- 0.90). In contrast, undervaccinated children had increased inpatient admission rates compared with age-appropriately vaccinated children (IRR, 1.21; 95% CI, 1.18-1.23). In a second matched cohort analysis, children who were undervaccinated because of parental choice had lower rates of outpatient visits (IRR, 0.94; 95% CI, 0.93-0.95) and emergency department encounters (IRR, 0.91; 95% CI, 0.88-0.94) than age-appropriately vaccinated children. CONCLUSIONS Undervaccination appears to be an increasing trend. Undervaccinated children appear to have different health care utilization patterns compared with age-appropriately vaccinated children.

Vaccination site and risk of local reactions in children 1 through 6 years of age.

OBJECTIVE: Our objective was to assess whether the occurrence of medically attended local reactions to intramuscularly administered vaccines varies by injection site (arm versus thigh) in children 1 to 6 years of age. METHODS: This is a retrospective cohort study of children in the Vaccine Safety Datalink population from 2002 to 2009. Site of injection and the outcome of medically attended local reactions were identified from administrative data. RESULTS: The study cohort of 1.4 million children received 6.0 million intramuscular (IM) vaccines during the study period. The primary analyses evaluated the IM vaccines most commonly administered alone, which included inactivated influenza, hepatitis A, and diphtheria-tetanus-acellular pertussis (DTaP) vaccines. For inactivated influenza and hepatitis A vaccines, local reactions were relatively uncommon, and there was no difference in risk of these events with arm versus thigh injections. The rate of local reactions after DTaP vaccines was higher, and vaccination in the arm was associated with a significantly greater risk of this outcome compared with vaccination in the thigh, both for children 12 to 35 months (relative risk: 1.88 [95% confidence interval: 1.34-2.65]) and 3 to 6 years of age (relative risk: 1.41 [95% confidence interval: 0.84-2.34]), although this difference was not statistically significant in the older age group. CONCLUSIONS: Injection in the thigh is associated with a significantly lower risk of a medically attended local reaction to a DTaP vaccination among children 12 to 35 months of age, supporting current recommendations to administer IM vaccinations in the thigh for children younger than 3 years of age.

Patterns in influenza antiviral medication use before and during the 2009 H1N1 pandemic, Vaccine Safety Datalink Project, 2000-2010.

BACKGROUND: U.S. recommendations for using influenza antiviral medications changed in response to viral resistance (to reduce adamantane use) and during the 2009 H1N1 pandemic (to focus on protecting high-risk patients). Little information is available on clinician adherence to these recommendations. We characterized population-based outpatient antiviral medication usage, including diagnosis and testing practices, before and during the pandemic. METHODS: Eight medical care organizations in the Vaccine Safety Datalink Project provided data on influenza antiviral medication dispensings from January 2000 through June 2010. Dispensing rates were explored in relation to changes in recommendations and influenza diagnosis and laboratory testing frequencies. Factors associated with oseltamivir dispensings in pandemic versus pre-pandemic periods were identified using multivariable logistic regression. RESULTS: Antiviral use changed coincident with recommendations to avoid adamantanes in 2006, to use alternatives to oseltamivir in 2008, and to use oseltamivir during the pandemic. Of 38,019 oseltamivir dispensings during the pandemic, 31% were to patients not assigned an influenza diagnosis, and 97% were to patients not tested for influenza. Oseltamivir was more likely to be dispensed in pandemic versus pre-pandemic periods to patients <25 years old and to those with underlying conditions, including chronic pulmonary disease or pregnancy (P<0.0001 for each factor in multivariable analysis). CONCLUSIONS: Antiviral medication usage patterns suggest that clinicians followed recommendations to change antiviral prescribing based on resistance and to focus on high-risk patients during the pandemic. Medications were commonly dispensed to patients without influenza diagnoses and tests, suggesting that antiviral dispensings may offer useful supplemental data for monitoring influenza incidence.

Safety of trivalent inactivated influenza vaccine in children aged 24 to 59 months in the vaccine safety datalink.

OBJECTIVES: To evaluate the safety of trivalent inactivated influenza vaccine (TIV) in children aged 24 to 59 months and to evaluate the risk of medically attended events (MAEs) in a subcohort of children who had multiple annual doses of TIV over their lifetimes. DESIGN: Self-controlled screening study. SETTING: Seven US managed care organizations from October 1, 2002, to March 31, 2006. PARTICIPANTS: Children aged 24 to 59 months who received at least 1 TIV dose (66 283 children and 91 692 TIV doses). EXPOSURE: Vaccination with TIV. MAIN OUTCOME MEASURES: Medically attended events in inpatient and emergency department settings in one of the following risk windows: 0 to 2, 1 to 14, or 1 to 42 days after vaccination. All MAEs that met the screening criteria of incidence rate ratios (IRRs) exceeding 1.0 and P ≤ .05 or IRRs exceeding 2.0 and P < .20 underwent medical record review. A secondary analysis examined the risk of MAEs in children who had multiple annual lifetime TIV doses. RESULTS: Nine diagnoses met the screening criteria. After medical record review, gastrointestinal tract symptoms (IRR, 1.18; 95% confidence interval [CI], 1.10-1.25), gastrointestinal tract disorders (7.70; 1.11-53.52), and fever (1.71; 1.64-1.80) remained significantly associated with vaccination. None of the events seemed to be serious, and none had complications. In the secondary analysis, there was an apparent dose response for vaccine and allergic reactions in the 1- to 3-day risk window. CONCLUSIONS: There was no evidence of serious MAEs following vaccination with TIV among children aged 24 to 59 months. Further studies are warranted to evaluate the risk of MAEs in children with multiple lifetime TIV doses.

Completion and timing of the three-dose human papillomavirus vaccine series among adolescents attending school-based health centers in Oregon.

OBJECTIVE: Many adolescents do not complete the 3-dose human papillomavirus vaccine series in the recommended time frame, or at all. Given the challenges of administering a multi-dose vaccine to adolescents, especially those in vulnerable populations, we evaluated completion of the human papillomavirus vaccine series in 19 of Oregon's school-based health centers. METHODS: Among persons aged 0-17 who initiated the human papillomavirus vaccine series at a study school-based health center in 2007, we identified all subsequent human papillomavirus doses administered at the school-based health centers, or found in Oregon's immunization information system, in 2007-2008. We describe the proportion completing the vaccine series and mean intervals between doses, stratified by age, race, and insurance status. RESULTS: Four hundred fifty persons initiated the human papillomavirus series in 2007. By December 2008, 51% of these had received all 3 doses. Series completion increased significantly with age, differed significantly between race groups (highest among white persons (56%); lowest among black persons (38%)), and did not differ significantly by insurance status. Mean intervals between doses did not differ significantly by race or insurance status. CONCLUSIONS: Even in challenging conditions, school-based health centers provide excellent preventive care to vulnerable youth. These results support the importance of maintaining and expanding school-based health center access in vulnerable adolescent populations.

Compliance with multiple-dose vaccine schedules among older children, adolescents, and adults: results from a vaccine safety datalink study.

OBJECTIVES: We studied compliance with multiple-dose vaccine schedules, assessed factors associated with noncompliance, and examined timeliness of series completion among older children, adolescents, and adults. METHODS: We conducted a large, multisite, retrospective cohort study of older children, adolescents, and adults in the Vaccine Safety Datalink population from 1996 through 2004. We quantified the rates of completion of all required doses for varicella, hepatitis A, and hepatitis B vaccines according to their recommended schedules. RESULTS: Among those who received a first dose of varicella (n = 16 075), hepatitis A (n = 594 917), and hepatitis B (n = 590 445) vaccine, relatively few completed the series (55%-65% for hepatitis B vaccine and 40%-50% for hepatitis A and varicella vaccines in most age groups). Compliance was lowest among adolescents (35.9%) and Medicaid recipients (29.7%) who received varicella vaccine and among younger adult age groups who received hepatitis A vaccine (25%-35% across those age groups). Even among series completers, there was a relatively long interval of undervaccination between the first and last doses. CONCLUSIONS: Compliance with multiple-dose vaccine series among older children, adolescents, and adults is suboptimal. Further evaluations of strategies to improve compliance in these populations are needed.

Gender differences in asthma management and quality of life.

We mailed a survey to a sample of adults with persistent asthma to assess gender differences in asthma management and quality of life. Women were more likely to regularly use a peak flow meter, have a regular clinician for their asthma care, and to have a written asthma management plan. No gender differences in self-reported asthma severity were observed, and men and women ranked their knowledge and confidence in their self-management skills similarly. Women reported significantly worse health status than men, but the differences observed were small and were attenuated after adjusting for socioeconomic status, smoking, body mass index, and comorbid illness.