Increasing Childhood Influenza Vaccination: A Cluster Randomized Trial

doi:10.1016/j.amepre.2014.07.003

American Journal of Preventive Medicine

Volume 47, Issue 4, October 2014, Pages 435-443

https://doi.org/10.1016/j.amepre.2014.07.003 Get rights and content

Background

Since the 2008 inception of universal childhood influenza vaccination, national rates have risen more dramatically among younger children than older children and reported rates across racial/ethnic groups are inconsistent. Interventions may be needed to address age and racial disparities to achieve the recommended childhood influenza vaccination target of 70%.

Purpose

To evaluate an intervention to increase childhood influenza vaccination across age and racial groups.

Methods

In 2011–2012, a total of 20 primary care practices treating children were randomly assigned to the intervention and control arms of a cluster randomized controlled trial to increase childhood influenza vaccination uptake using a toolkit and other strategies including early delivery of donated vaccine, in-service staff meetings, and publicity.

Results

The average vaccination differences from pre-intervention to the intervention year were significantly larger in the intervention arm (n=10 practices) than the control arm (n=10 practices); for children aged 9–18 years (11.1 pct pts intervention vs 4.3 pct pts control, p<0.05); for non-white children (16.7 pct pts intervention vs 4.6 pct pts control, p<0.001); and overall (9.9 pct pts intervention vs 4.2 pct pts control, p<0.01). In multi-level modeling that accounted for person- and practice-level variables and the interactions among age, race, and intervention, the likelihood of vaccination increased with younger age group (6–23 months); white race; commercial insurance; the practice’s pre-intervention vaccination rate; and being in the intervention arm. Estimates of the interaction terms indicated that the intervention increased the likelihood of vaccination for non-white children in all age groups and white children aged 9–18 years.

Conclusions

A multi-strategy intervention that includes a practice improvement toolkit can significantly improve influenza vaccination uptake across age and racial groups without targeting specific groups, especially in practices with large percentages of minority children.

Introduction

Since 2008, recommendations for annual influenza vaccination have included all children aged 6 months and older.¹ Although vaccination rates among younger children have nearly reached or exceeded the national target of 70%,² rates among older children are disappointingly low. For example, infants (aged 6–23 months) are most frequently vaccinated (77%), followed by preschoolers (aged 2–4-years, 66%), young children (aged 5–12 years, 59%), and older children (aged 13–18 years, 43%).³ Similar rates in the younger age groups and lower rates in the older age groups were reported in a study⁴ of urban children in a single city.

Research examining age disparities is scant, but they may be explained by lower contact with the healthcare system among older children. In a study⁵ of children aged 6–23 months, those with more frequent contact with the practice during influenza season were more likely to be vaccinated. It is unknown whether intervention strategies designed to increase childhood influenza vaccination rates are effective for children of all ages because most of the intervention studies that have included several age groups predate universal vaccination and focus either on infants or high-risk older children. One recent RCT⁶ using text message reminders for influenza vaccination reported significant increases in rates among younger children but not among those aged 5–18 years.

In addition to age disparities in influenza vaccination rates, there is some evidence of racial disparities. In adults, most non-white groups have reported lower influenza vaccination rates than non-Hispanic whites (34% for Hispanics, 36% for blacks, 45% for Asians, 41% for American Indians/Alaska Natives, and 45% for whites),³ whereas, national data for 2012–2013 among children aged 6 months–17 years indicated that Hispanic (61%), Asian (66%), and black (57%) children all had higher vaccination rates than non-Hispanic white (54%) and American Indian/Alaska Native (53%) children.³ Thus, national data reveal that overall rates in 2012–2013 were higher and racial differences were smaller among children than among adults.

Other research among children in specific locales has demonstrated varying differences in influenza vaccination rates across racial groups, with no differences reported between black and Latino low-income children⁷; higher rates among white children than black children in inner-city practices8, 9; higher rates among white children than Latino and non-Latino black children in practices in low-income urban communities⁴; and higher rates among Asian and Hispanic children than among non-Hispanic white children in community health centers.¹⁰ Three of these studies were conducted before universal vaccination,7, 8, 9 and two4, 10 were based on data collected during the first year of universal vaccination recommendations.

As with age disparities, the effectiveness of interventions to raise childhood influenza vaccination uptake across racial groups is unknown. The purpose of this study is to determine whether an intensive intervention based on a toolkit of strategies (the 4 Pillars Toolkit, pittvax.pitt.edu/childflu/papertoolkit), implemented in primary care practices in a cluster randomized controlled trial, was effective for increasing the proportion of children who received influenza vaccine across various age and racial groups in 2011–2012.

Section snippets

Methods

This randomized cluster trial was approved by the University of Pittsburgh IRB.

Demographics

Twenty primary care practices were randomly assigned to either the intervention or control arm. Two control sites dropped out of the study and were replaced with two other sites with similar characteristics and those data were used for all analyses. Table 1 summarizes the characteristics of sites during the pre-intervention year. The intervention and control arms did not differ significantly by percentage of non-white children, percentage of children publicly or self-insured, percentage of

Discussion

Since the 2008 recommendations by the Advisory Committee on Immunization Practices for universal influenza vaccination of all children aged 6 months and older, little research has been published on efforts to increase uptake across the childhood age spectrum. Stockwell et al.⁶ used text messages to increase influenza vaccine uptake 3.7% across all ages, with significant increases only among children <5 years old. The present study used a package of interventions including a practice improvement

Strengths and Limitations

To date, this study is one of few trials to examine the effect of an evidence-based intervention on childhood influenza vaccination rates across age and racial groups. Only one previous non-randomized study¹⁶ was identified that looked at the relationship of a similar set of interventions in a toolkit on rates among high-risk children and adolescents. The present study’s limitations included the fact that two offices of one rural practice were each randomized into the intervention and control

Acknowledgments

The authors thank the University of Pittsburgh Clinical and Translational Science Institute Pediatric PittNet practice-based research network and the following site investigators: Tracey Conti, MD, Mark Diamond, MD, Harold Glick, MD, Phillip Iozzi, DO, Kenneth Keppel, MD, John J. Labella, MD, Sanjay Lambore, MD, Sheldon Levine, MD, Thomas G. Lynch, MD, Elaine McGhee, MD, Paul Rowland, MD, Robert Rutowski, MD, Pamela Schoemer, MD, Emeil Shenouda, MD, Aaron Smuckler, MD, Scott Tyson, MD, Donald

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Cited by (12)

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Increasing influenza vaccination coverage in school-aged children may substantially reduce community transmission. School-located influenza vaccinations (SLIV) aim to promote vaccinations by increasing accessibility, which may be especially beneficial to race/ethnicity groups that face high barriers to preventative care. Here, we evaluate the effectiveness of a city-wide SLIV program by race/ethnicity from 2014 to 2018.
We used multivariate matching to pair schools in the intervention district in Oakland, CA with schools in a comparison district in West Contra Costa County, CA. We distributed cross-sectional surveys to measure caregiver-reported student vaccination status and estimated differences in vaccination coverage levels and reasons for non-vaccination between districts stratifying by race/ethnicity. We estimated difference-in-differences (DID) of laboratory confirmed influenza hospitalization incidence between districts stratified by race/ethnicity using surveillance data.
Differences in influenza vaccination coverage in the intervention vs. comparison district were larger among White (2017–18: 21.0% difference [95% CI: 9.7%, 32.3%]) and Hispanic/Latino (13.4% [8.8%, 18.0%]) students than Asian/Pacific Islander (API) (8.9% [1.3%, 16.5%]), Black (5.9% [−2.2%, 14.0%]), and multiracial (6.3% [−1.8%, 14.3%)) students. Concerns about vaccine effectiveness or safety were more common among Black and multiracial caregivers. Logistical barriers were less common in the intervention vs. comparison district, with the largest difference among White students. In both districts, hospitalizations in 2017–18 were higher in Blacks (Intervention: 111.5 hospitalizations per 100,00; Comparison: 134.1 per 100,000) vs. other races/ethnicities. All-age influenza hospitalization incidence was lower in the intervention site vs. comparison site among White/API individuals in 2016–17 (DID −25.14 per 100,000 [95% CI: −40.14, −10.14]) and 2017–18 (−36.6 per 100,000 [−52.7, −20.5]) and Black older adults in 2017–18 (−282.2 per 100,000 (−508.4, −56.1]), but not in other groups.
SLIV was associated with higher vaccination coverage and lower influenza hospitalization, but associations varied by race/ethnicity. SLIV alone may be insufficient to ensure equitable influenza outcomes.
Parental Vaccine Hesitancy and Risk of Pediatric Influenza Under-Vaccination in a Safety-Net Health Care System
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Citation Excerpt :
Children in the intervention arm had a 10% increase in vaccination uptake, versus just 4% in the control arm (P = .01), and the benefits were highest for non-White children (17% uptake vs 5% uptake; P < .01).39 However, the 4-part intervention did not address vaccine hesitancy, and the authors concluded interventions can successfully improve vaccination uptake without targeting specific groups, such as racial/ethnic minorities.39 Our study results demonstrate that pediatric influenza vaccination interventions in safety-net systems must address parental vaccine hesitancy in addition to other multilevel barriers.
To measure the risk of influenza under-vaccination in children of vaccine-hesitant parents, referent to children of nonhesitant parents, in a sample of disadvantaged families in one influenza season.
A prospective observational cohort study of English- and Spanish-speaking parents of 2-year-olds presenting at random for well, sick, or specialty visit care from August 1, 2019 to February 28, 2020. Parents answered demographic questions and the Parent Attitudes about Childhood Vaccines survey. We followed children until season's end, extracting vaccination data on April 30, 2020. We dichotomized vaccination status as unvaccinated or partially/fully vaccinated, analyzing data with multivariable Poisson regression; in secondary analyses, we conducted adjusted time-to-event analyses.
Overall, 263 parents consented (response rate: 90%); our final sample included 255 dyads. Thirty-three (13%) parents were vaccine hesitant. In adjusted analyses, children of hesitant parents (n = 33) had a 195% increased risk (adjusted Risk Ratio 2.95; 95% confidence interval 1.91, 4.56) of being unvaccinated at season's end, referent to children of nonhesitant parents (n = 222). In time-to-event analyses, children of vaccine-hesitant parents were also more likely to be unvaccinated before influenza activity peaked (P = .02).
Parental vaccine hesitancy tripled the risk of pediatric influenza nonvaccination in a sample of poor and minority families during the 2019 to 2020 influenza season. As parental vaccine hesitancy appears to exacerbate pediatric influenza vaccination disparities, future work should explore parental hesitancy with poor and minority stakeholders and tailor evidence-based interventions to benefit children from these communities who receive care at all practice sites.
The role and challenges of cluster randomised trials for global health
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Interventions themselves can be administered at a cluster level (eg, mosquito egg traps5) or at an individual level (eg, vaccinations6). In cluster trials, outcomes can be measured at a cluster level6 or at an individual level.7 There is an increasing popularity of the use of cluster trials in low-income and middle-income countries (LMICs).8
Evaluating whether an intervention works when trialled in groups of individuals can pose complex challenges for clinical research. Cluster randomised controlled trials involve the random allocation of groups or clusters of individuals to receive an intervention, and they are commonly used in global health research. In this paper, we describe the potential reasons for the increasing popularity of cluster trials in low-income and middle-income countries. We also draw on key areas of global health research for an assessment of common trial planning practices, and we address their methodological shortcomings and pitfalls. Lastly, we discuss alternative approaches for population-level intervention trials that could be useful for research undertaken in low-income and middle-income countries for situations in which the use of cluster randomisation might not be appropriate.
Variability in influenza vaccination opportunities and coverage among privately insured children
2020, Vaccine
Citation Excerpt :
Another potential strategy is to administer influenza vaccination during school hours (school-located influenza vaccination), removing the need for a healthcare visit to receive vaccination [24,25]. Prior research is conflicting on whether influenza vaccination coverage is higher among privately insured children versus those with public health insurance [26–29]. Our analysis further examines variations in in-plan vaccination coverage by private insurance plan type and finds both vaccination coverage and vaccination opportunities are lower in FFS plans compared to other health plan types.
Universal influenza vaccination has been recommended since 2010, yet influenza vaccination rates among children aged 6 months to 17 years remain low compared with other routinely recommended childhood vaccines.
Assess in-plan vaccination coverage, opportunities, and missed opportunities during the 2016–2017 influenza season.
Retrospective analyses using 2016–2017 MarketScan® data for 2,768,799 privately insured children aged 1–17 years by the end of 2016 who were continuously enrolled in the same insurance plan during the 2016–2017 influenza season (defined as August 1, 2016 through May 31, 2017). We assessed in-plan vaccination coverage (percentage receiving ≥ 1 dose of influenza vaccine from August 2016-May 2017) and vaccination opportunities (percentage with ≥ 1 provider visit between September 2016 – May 2017). Among children who remained unvaccinated at the end of the season, those with ≥ 1 influenza vaccination opportunity between September 2016-May 2017 were determined to have a missed opportunity.
In-plan vaccination coverage during the 2016–17 season was 67.7% in infants (born 2015), 49.5% in toddlers (born 2012–2014), 35.0% in school-aged children (born 2004–2011), and 22.3% in teenagers (born 1999–2003). Like vaccination coverage, vaccination opportunities decreased with age (infants: 97.7%, toddlers: 91.9%, school-aged children: 82.6%, teenagers: 79.3%). Among unvaccinated children, 93.1%, 84.1%, 73.6% and 73.6% of each age group had a missed opportunity for influenza vaccination.
Opportunities for and coverage with influenza vaccination vary even among privately insured children. Along with continued efforts to reduce missed opportunities, effective strategies to bring children to their doctor for annual influenza vaccination are needed, particularly for older children.
Be inFLUential: Evaluation of a multifaceted intervention to increase influenza vaccination rates among pediatric inpatients
2020, Vaccine
Citation Excerpt :
Vaccination efforts benefit from multi-strategy interventions [21]. This has been demonstrated in studies evaluating influenza immunization interventions in clinic settings [22–25]. There is emerging data of the benefits of this approach in inpatient settings [26].
Annual influenza vaccination is recommended for individual ≥6 months of age, yet vaccination rates remain below national targets in the US. Hospitalization provides another medical setting for influenza vaccination, but the effectiveness of inpatient interventions has not been well studied. Our objective was to evaluate the effectiveness of a multifaceted intervention to increase influenza vaccination rates among pediatric inpatients.
We conducted a pre-post interventional study on medical inpatient units at Children’s Hospital Colorado from September 2016-April 2017 (pre-intervention) and September 2017-April 2018 (intervention). The intervention targeted nurses (web-based education modules, huddles and reminders) and providers (vaccination lists in the electronic health record, reminders, vaccination reports and financial incentives for residents). Outcomes were influenza vaccine ordering rates, and influenza vaccination rates at discharge. We analyzed data using descriptive statistics, bivariate and logistic regression.
Among 4,050 inpatients in 2016–2017 and 4,523 inpatients in 2017 aged ≥ 6 months, vaccination status was documented for 2,902/4,050 (71.7%) and 3,431/4,523 (75.9%) children aged > 6 months of age hospitalized during the study period. The vaccine ordering rate among eligible children was 28.8% in the pre-intervention season versus 50.2% in the intervention season (p < 0.001). The intervention was associated with 1.23 (95% CI 1.11–1.35) times higher odds of appropriate vaccination screening on admission, 2.27 (95% CI 2.01–2.56) times higher odds of a vaccination being ordered, and 1.39 (95% CI 1.27–1.53) times higher odds of a child being vaccinated against influenza at discharge (all p < 0.001). Residents (56%) and medical providers (39%) were more likely to order vaccines compared with nurses (5%), p = 0.014).
A multifaceted intervention targeting nurses, residents and providers comprising education, visual reminders, vaccination reports and financial incentives is an effective way of improving influenza vaccine ordering, resulting in higher inpatient influenza vaccination rates.
Offering the Influenza Vaccine in a Pediatric Hand Surgery Clinic Increases Vaccination Rates
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Clinics that offer the vaccine include Primary Care Pediatrics, Allergy, Hematology/Oncology, Endocrinology, Infectious Diseases, Gastrointestinal, and Pulmonary. Several key factors serve to increase influenza vaccination rates, including convenient vaccination services (offered at the appointment) and enhanced office systems to facilitate immunization (eg, nurse buy-in, standing order sets).7,11 Barriers to children receiving influenza vaccine include lack of convenience to receive the vaccine (not offered at the appointment) and parental misperception regarding the risks of developing influenza infection and the potential severe outcomes of influenza disease.13
The purpose of this study was to evaluate the utility of providing immediate access to the influenza vaccination for patients seen in a pediatric hand surgery clinic. Our hypothesis was that providing access would increase the rate of vaccination.
This pilot study was a randomized, controlled, prospective clinical trial that included all patients seen by a single surgeon, on a single day each week, in a hospital-based pediatric hand surgery practice clinic from October 18, 2016, to March 14, 2017. All patients between 6 months and 18 years of age seen during their initial visit during the study period were included. All patients were questioned on their vaccine status. For the intervention group, the influenza vaccine was offered. If requested, after providing educational materials, written consent from the parent or guardian was obtained. The vaccine was given by the registered nurse ordinarily assigned to the clinic. Demographic information and vaccine status for both groups at the end of clinic, including the date of receiving the vaccine, were recorded.
Similar proportions of patients in each group had received the vaccine prior to being seen in the clinic. In the intervention group, 80 children (67%) had received the vaccine by the end of clinic, compared with 29 (25%) in the control group. Patients who were offered the vaccine had a statistically significant higher vaccination rate. Of the 80 patients in the intervention group who received the vaccine, 47 (59%) received it in the hand clinic.
This project demonstrated that offering the influenza vaccine in a nontraditional setting, an outpatient hand surgery clinic, increased the proportion of patients receiving the vaccine.
Therapeutic I.

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Research ArticleIncreasing Childhood Influenza Vaccination: A Cluster Randomized Trial

Background

Purpose

Methods

Results

Conclusions

Introduction

Section snippets

Methods

Demographics

Discussion

Strengths and Limitations

Acknowledgments

Vaccine

Vaccine

Vaccine

Vaccine

Prevention and control of influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices (ACIP), 2010

MMWR Morb Mortal Wkly Rep

Timeliness of pediatric influenza vaccination compared with seasonal influenza activity in an urban community, 2004–2008

Am J Public Health

Research Article
Increasing Childhood Influenza Vaccination: A Cluster Randomized Trial