A validated modification of the vaccine hesitancy scale for childhood, influenza and HPV vaccines.

INTRODUCTION: Vaccine hesitancy contributes to outbreaks of preventable disease worldwide. The Vaccine Hesitancy Scale (VHS), developed by the international WHO SAGE Working Group, has been validated previously for measuring hesitancy towards childhood vaccines; some psychometric properties were suboptimal. METHODS: We collected data using large, nationally-representative samples of parents in the U.S. We adapted the VHS items, and additional hesitancy items, to assess hesitancy towards influenza and HPV vaccines in addition to routine childhood vaccines. We then used exploratory and confirmatory factor analysis to identify latent constructs and create modified scales for childhood (VHS-child), influenza (VHS-flu) and HPV (VHS-HPV) vaccines with improved psychometric properties. Finally, we compared hesitancy scores on the VHS-child, VHS-flu, and VHS-HPV, to self-reported receipt of each vaccine category, and compared subscale scores to assess whether drivers of hesitancy differed by vaccine category. RESULTS: 2052 parents of children <18 years old completed the VHS-child and VHS-flu while 2020 parents of adolescents completed the VHS-HPV. A two-factor structure of 'risks' and a 'lack of confidence' was found for each vaccine category. Slight modifications to the VHS improved psychometric properties. Hesitancy was strongly associated with vaccine receipt: e.g., 76% of parents not hesitant towards influenza vaccine had vaccinated their child the past season, versus 9% of hesitant parents (p < 0.0001). Subscale scores also differed significantly between vaccines: lack of confidence was greater towards influenza (Median (IQR): 2.0 (1.2, 3.3)) and HPV (2.0 (1.3, 3.0)) vaccines than childhood (1.2 (1.0, 1.8), p < 0.0001 for both) vaccines; perceived risks of HPV vaccines (2.7 (1.7, 3.7)) were greater than for childhood vaccines (2.0 (1.3, 3.0), p < 0.0001). CONCLUSIONS: Our modified VHS scales perform well psychometrically and allow for consistent measurement of the extent and reasons for hesitancy between vaccine categories. We suggest that future work use these scales to examine hesitancy towards other vaccines and to monitor hesitancy over time.

The potential for centralized reminder/recall to increase immunization rates: A national survey of immunization information systems (IIS) managers.

Little is known about Immunization Information System (IIS) attitudes and experiences using Centralized IIS-based Reminder/Recall (CI-R/R), an effective approach to increasing immunization rates. To describe among IIS managers as it relates to CI-R/R: 1) past experiences and future plans conducting it; 2) attitudes and barriers, 3) IIS capabilities and polices that influence, and 4) factors that differentiate IIS who have and have not conducted CI-R/R. Electronic Surveys were sent to all IIS managers in July 2018 using a member listserve. Fifty-seven of 62 IIS programs contacted (92%) responded. The majority (61%) had ever conducted CI-R/R; 34% reported they were "very likely" to conduct CI-R/R within 6 months. The majority (64%) were in favor of CI-R/R. Barriers included lack of staff (78%), competing demands (76%), and cost (63%). Thirty percent reported receiving a ≥75% of immunization data via real-time electronic interfaces (HL7). Overall, 49% and 24% of jurisdictions had mandatory immunization reporting from private and public health entities for childhood and adult immunizations, respectively. Differences between IIS that ever and never performed CI-R/R, respectively, included: mandatory reporting from private and public entities for children (65% v 27%, p = 0.006), having a legal mandate for CI-R/R (50% v 19%, p = 0.02), less likely to prefer practice-based R/R to CI-R/R (68% v. 91%, p = 0.04), and not reporting having too many competing demands (29% v 67%, p = 0.007). Most IIS have conducted CI-R/R and have positive attitudes towards it. Given it effectiveness and low cost, efforts to sustain it should be considered.

Prevalence and characteristics of HPV vaccine hesitancy among parents of adolescents across the US.

BACKGROUND: While many clinicians encounter parents or adolescents who refuse HPV vaccine, little is known about the prevalence of hesitancy for HPV vaccine nationally or its association with vaccination. METHODS: In April 2019, we surveyed families with adolescents 11-17 years using a national online panel (Knowledge Panel®) as the sampling frame. We assessed the prevalence of HPV vaccine hesitancy with the validated 9-item Vaccine Hesitancy Scale (VHS). We used multivariate analyses to assess demographic factors associated with HPV vaccine hesitancy. We also assessed practical barriers to receipt of HPV vaccine and the relationship between barriers and hesitancy. Finally, we evaluated the association between both HPV vaccine hesitancy and practical barriers on HPV vaccine receipt or refusal. RESULTS: 2,177 parents out of 4,185 sampled (52%) completed the survey, 2,020 qualified (lived with adolescent). Using a VHS cut-off score > 3 out of 5 points, 23% of US parents were hesitant about HPV vaccine. Hesitancy was lower among those with Hispanic ethnicity. At least one out of five parents disagreed that the HPV vaccine is beneficial for their adolescent, that the vaccine is effective, protects against HPV-related cancers, or that they followed their adolescent's health-care provider's recommendation about the vaccine. Many were concerned about vaccine side effects and the novelty of the vaccine. Adolescents living with vaccine-hesitant parents were less than one-third as likely to have received the vaccine (RR = 0.29, 95% CI 0.24, 0.35) or completed the vaccine series (RR = 0.29, 95% CI 0.23, 0.36), and were 6-fold more likely to have refused the vaccine because of parental vaccine-related concerns (RR = 6.09, 95% CI = 5.26, 7.04). Most practical barriers were independently associated with vaccine receipt but not with vaccine refusal. CONCLUSIONS: HPV vaccine hesitancy is common nationally and strongly related to both under-vaccination and vaccine refusal.

Parental Hesitancy About Routine Childhood and Influenza Vaccinations: A National Survey.

BACKGROUND AND OBJECTIVES: The World Health Organization has designated vaccine hesitancy as 1 of the 10 leading threats to global health, yet there is limited current national data on prevalence of hesitancy among US parents. Among a nationally representative sample of US parents, we aimed to (1) assess and compare prevalence of hesitancy and factors driving hesitancy for routine childhood and influenza vaccination and (2) examine associations between sociodemographic characteristics and hesitancy for routine childhood or influenza vaccination. METHODS: In February 2019, we surveyed families with children using the largest online panel generating representative US samples. After weighting, we assessed hesitancy using a modified 5-point Vaccine Hesitancy Scale and labeled parents as hesitant if they scored >3. RESULTS: A total of 2176 of 4445 parents sampled completed the survey (response rate 49%). Hesitancy prevalence was 6.1% for routine childhood and 25.8% for influenza vaccines; 12% strongly and 27% somewhat agreed they had concerns about serious side effects of both routine childhood and influenza vaccines. A total of 70% strongly agreed that routine childhood vaccines are effective versus 26% for influenza vaccine (P < .001). In multivariable models, an educational level lower than a bachelor's degree and household income <400% of the federal poverty level predicted hesitancy about both routine childhood and influenza vaccines. CONCLUSIONS: Almost 1 in 15 US parents are hesitant about routine childhood vaccines, whereas >1 in 4 are hesitant about influenza vaccine. Furthermore, 1 in 8 parents are concerned about vaccine safety for both routine childhood and influenza vaccines, and only 1 in 4 believe influenza vaccine is effective. Vaccine hesitancy, particularly for influenza vaccine, is prevalent in the United States.

Effect of State Immunization Information System Based Reminder/Recall for Influenza Vaccinations: A Randomized Trial of Autodialer, Text, and Mailed Messages.

OBJECTIVE: To evaluate the effect of different modalities of centralized reminder/recall (autodialer, text, mailed reminders) on increasing childhood influenza vaccination. STUDY DESIGN: Two simultaneous randomized clinical trials conducted from October 2017 to April 1, 2018, in New York State and Colorado. There were 61 931 children in New York (136 practices) and 23 845 children in Colorado (42 practices) who were randomized to different centralized reminder/recall modalities-4 arms in New York (autodialer, text, mailed, and no reminder control) and 3 arms in Colorado (autodialer, mailed, and no reminder control). The message content was similar across modalities. Up to 3 reminders were sent for intervention arms. The main outcome measure was receipt of ≥1 influenza vaccine. RESULTS: In New York, compared with the control arm (26.6%), postintervention influenza vaccination rates in the autodialer arm (28.0%) were 1.4 percentage points higher (adjusted risk ratio, 1.06; 95% CI, 1.02-1.10), but the rates for text (27.6%) and mail (26.8%) arms were not different from controls. In Colorado, compared with the control arm (29.9%), postintervention influenza vaccination rates for the autodialer (32.9%) and mail (31.5%) arms were 3.0 percentage points (adjusted risk ratio, 1.08; 95% CI, 1.03-1.12) and 1.6 percentage points (adjusted risk ratio, 1.06; 95% CI, 1.02-1.10) higher, respectively. Compared with the control arm, the incremental cost per additional vaccine delivered was $20 (New York) and $16 (Colorado) for autodialer messages. CONCLUSIONS: Centralized reminder/recall for childhood influenza vaccine was most effective via autodialer, less effective via mail, and not effective via text messages. The impact of each modality was modest. Compared with no reminders, the incremental cost per additional vaccine delivered was also modest for autodialer messages. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03294473 and NCT03246100.

Centralized Reminder/Recall to Increase Influenza Vaccination Rates: A Two-State Pragmatic Randomized Trial.

OBJECTIVE: Centralized reminder/recall (C-R/R) by health departments using immunization information systems is more effective and cost effective than practice-based approaches for increasing childhood vaccines but has not been studied for influenza vaccination. We assessed effectiveness and cost of C-R/R for increasing childhood influenza vaccination compared with usual care. METHODS: Within Colorado (CO) and New York (NY), random samples of primary care practices (pediatric, family medicine, and health center) were selected proportionate to where children are served-65 practices (N = 54,353 children) in CO; 101 practices (N = 65,777) in NY. We conducted 4-arm RCTs per state (1, 2, or 3 autodial reminders vs usual care), with randomization at the patient level within practices from 10/2016 to 1/2017. RESULTS: In CO, the maximum absolute difference in receipt of ≥1 influenza vaccine was 1.7% between the 2 R/R group and control (adjusted risk ratio [ARR] of 1.06 [1.01, 1.10]); other R/R arms did not differ significantly. In NY, ARRs for the study arms versus control varied from 1.05 (1.01, 1.10) for 3 R/R to 1.06 (1.01, 1.11) for 1-2 R/R groups and maximum absolute increase in vaccination was 0.6%. In time-to-event analyses, study arm was a significant predictor of vaccination in CO (P = .001) but not in NY. Costs/child randomized to one message were $.17 in CO and $.23 in NY. CONCLUSIONS: C-R/R for influenza vaccine using autodial had low-level effects on increasing influenza rates in 2 states. Given the feasibility and low cost of C-R/R in previous trials, its utility for influenza should be re-examined using different modalities.

Potential Strategies to Achieve Universal Influenza Vaccination for Children: Provider Attitudes in Two States.

OBJECTIVE: Childhood influenza vaccination rates remain suboptimal. Provider perceptions on strategies to achieve universal vaccination are needed. We assessed the perceptions and attitudes of primary care providers across 2 states regarding 2 strategies to potentially bolster rates: centralized reminder/recall (C-R/R), such as reminder/recall (R/R) notices from state immunization registries, and influenza vaccination by complementary community vaccinators (CCVs), such as retail pharmacies, schools, and health departments. METHODS: We sent a mailed survey to a representative sample of providers across Colorado and New York. Questions addressed R/R activities for influenza vaccine, preferences and attitudes about the health department sending C-R/R notices for influenza vaccine, and attitudes about CCVs. Bivariate analyses assessed provider perceptions and compared perceptions by state. RESULTS: The overall response rate was 56% (n = 590/1052). Twenty-two percent of providers in Colorado and 33% in New York performed practice-based R/R for all patients during the 2015-16 influenza season. Eighty-one percent of providers in both states preferred the health department or had no preference for who sent C-R/R notices for influenza vaccine to their patients; most preferred to include their practice names on C-R/R messages. Many providers in both Colorado (75%) and New York (46%, P < .001) agreed that their patients like the option of having CCVs where children can receive influenza vaccine. Some providers expressed concerns regarding potential loss of income and/or difficulty documenting receipt of influenza vaccine at CCVs. CONCLUSIONS: Most providers support C-R/R, and many support CCVs to increase influenza vaccination rates. Collaborations between traditional primary care providers and CCVs might boost coverage.

Centralized Reminder/Recall to Increase Immunization Rates in Young Children: How Much Bang for the Buck?

OBJECTIVE: We compared the effectiveness and cost-effectiveness of: 1) centralized reminder/recall (C-R/R) using the Colorado Immunization Information System (CIIS) versus practice-based reminder/recall (PB-R/R) approaches to increase immunization rates; 2) different levels of C-R/R intensity; and 3) C-R/R with versus without the name of the child's provider. METHODS: We conducted 3 sequential cluster-randomized trials involving children aged 19 to 25 months in 15 Colorado counties in March 2013 (trial 1), October 2013 (trial 2), and May 2014 (trial 3). In C-R/R counties, the intensity of the intervention decreased sequentially in trials 1 through 3, from 3 to 1 recall messages. In PB-R/R counties, practices were offered training using CIIS and financial support. The percentage of children with up-to-date (UTD) vaccinations was compared 6 months after recall. A mixed-effects model assessed the association between C-R/R versus PB-R/R and UTD rates. RESULTS: C-R/R was more effective in trials 1 to 3 (relative risk = 1.11; 95% confidence interval 1.01-1.20; P = .009). Effectiveness did not decrease with decreasing intervention intensity (P = .59). Costs decreased with decreasing intensity in the C-R/R arm, from $18.72 per child brought UTD in trial 1 to $10.11 in trial 3. Costs were higher and more variable in the PB-R/R arm, ranging from $20.63 to $237.81 per child brought UTD. C-R/R was significantly more effective if the child's practice name was included (P < .0001). CONCLUSIONS: C-R/R was more effective and cost-effective than PB-R/R for increasing UTD rates in young children and was most effective if messages included the child's provider name. Three reminders were not more effective than one, which may be explained by the increasing accuracy of contact information in CIIS over the course of the trials.

Provider Preferences and Experiences With a Countywide Centralized Collaborative Reminder/Recall for Childhood Immunizations.

OBJECTIVE: To assess among providers in 7 Colorado counties where a collaborative centralized reminder/recall (CC-R/R) using the Colorado Immunization Information System (CIIS) was performed: 1) preferences about CC-R/R conducted by the public health department (PHD); 2) preferences for future CC-R/R for different vaccines with and without practice names; and 3) experiences with including their name on CC-R/R notices. METHODS: A mailed survey was sent to all primary care sites where CC-R/R had been previously conducted. Respondents self-identified as the "the person in charge of immunization policy within the practice." RESULTS: Overall response rate was 69.9% (160 of 229). Twenty-one were removed because they did not provide immunizations to children. Among respondents, 65.0% were from family medicine and 26.3% from pediatric practices; 32.1% physicians or midlevel providers; 34.3% nurses or medical assistants; and 33.6% office managers. Taking into account all issues, 57.6% were "okay" with either the PHD or their practice conducting recall; 27.3% preferred the PHD; and 14.4% preferred their practice conduct R/R. Fifty-six percent of active CIIS practices (n = 95) included their practice's name on CC-R/R notices. Interest in future CC-R/R for different ages and vaccines was strongly related to whether reminders included the practice name: 77.8% for routine immunizations in 4- to 6-year-olds; 74.8% for immunizations for 0- to 3-year-olds; 73.3% for vaccines administered to adolescents; and 59.7% for influenza (P < .001). CONCLUSIONS: Most practices are accepting of the PHD centrally conducting R/R, but most prefer collaboration that includes their name. Given the success and support of this method, it should be more widely adopted.

Collaborative centralized reminder/recall notification to increase immunization rates among young children: a comparative effectiveness trial.

IMPORTANCE: Reminder/recall notifications used by primary care practices increase the rates of childhood immunizations, but fewer than 20% of primary care practitioners nationally deliver such reminders. A reminder/recall notification conducted centrally by health departments in collaboration with primary care practices may reduce practice burden, reach children without a primary care practitioner, and decrease the cost of reminders/recalls. OBJECTIVE: To assess the effectiveness and cost-effectiveness of collaborative centralized (CC) vs practice-based (PB) reminder/recall approaches using the Colorado Immunization Information System (CIIS). DESIGN, SETTING, AND PARTICIPANTS: We performed a randomized pragmatic trial from September 7, 2012, through March 17, 2013, including 18,235 children aged 19 to 35 months in 15 Colorado counties. INTERVENTIONS: In CC counties, children who needed at least 1 immunization were sent as many as 4 reminders/recalls by mail or autodialed telephone calls by the CIIS. Primary care practices in these counties were given the option of endorsing the reminder/recall notification by adding the practice name to the message. In PB counties, primary care practices were invited to web-based reminder/recall training and offered financial support for sending notifications. MAIN OUTCOMES AND MEASURES: Documentation of any new immunization within 6 months constituted the primary outcome; achieving up-to-date (UTD) immunization status was secondary. We assessed the cost and cost-effectiveness of each approach and used a generalized linear mixed-effects model to assess the effect of the intervention on outcomes. RESULTS: In PB counties, 24 of 308 primary care practices (7.8%) attended reminder/recall training and 2 primary care practices (0.6%) endorsed reminder/recall notifications. Within CC counties, 129 of 229 practices (56.3%) endorsed the reminder/recall letter. Documentation rates for at least 1 immunization were 26.9% for CC vs 21.7% for PB counties (P < .001); 12.8% vs 9.3% of patients, respectively, achieved UTD status (P < .001). The effect of CC counties on children's UTD status was greater when the reminder/recall notification was endorsed by the primary care practice (19.2% vs 9.8%; P < .001). The total cost of the CC reminder/recall was $28 620 or $11.75 per child for any new immunization and $24.72 per child achieving UTD status; the total cost to the 2 practices that conducted PB reminders/recalls was $74.00 per child for any immunization and $124.45 per child achieving UTD status. The modeling resulted in an adjusted odds ratio of 1.31 (95% CI, 1.16-1.48) for any new immunization in CC vs PB counties. CONCLUSIONS AND RELEVANCE: A CC reminder/recall notification was more effective and more cost-effective than a PB system, although the effect size was modest. Endorsement by practices may further increase the effectiveness of CC reminder/recall. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01557621.

Novel immunization reminder/recall approaches: rural and urban differences in parent perceptions.

OBJECTIVE: To assess the following among parents of young children: (1) preferences about the source of immunization reminder/recall (R/R) messages, (2) the degree of acceptability of different R/R modalities, and (3) factors that influence preferences, including rural and urban characteristics. METHODS: We conducted a survey among parents of children 19 to 35 months old who needed ≥1 immunization according to the Colorado Immunization Information System (CIIS). Equal numbers of urban and rural respondents were randomly selected. Up to 4 surveys were mailed to each parent who had a valid address. RESULTS: After removing invalid addresses, the response rate was 55% (334 of 607). Half of parents (49.7%) had no preference about whether the public health department or their child's doctor sent reminders. Urban parents were more likely to prefer R/R come from their child's doctor (46.7%) compared to rural parents (33.7%), P = .003. Mail was the preferred R/R method (57.7%), then telephone (17.0%), e-mail (12.7%), and text message (10.7%). Although not preferred, 60.1% reported it would be acceptable to receive R/R by e-mail and 46.2% by text message. Factors associated with preferring to receive R/R from their child's doctor were urban residence and educational level of college graduate or greater. CONCLUSIONS: A large portion of parents are willing to be reminded about vaccinations by their health department rather than their child's provider and via novel modalities, such as e-mail or text messaging. Urbanicity and higher educational level were associated with preferring that R/R come from a provider.

Getting under the hood: exploring issues that affect provider-based recall using an immunization information system.

OBJECTIVE: To assess 1) pediatric practices' use of provider-based recall using an immunization information system 8 months after training on the recall process; 2) initiation and sustainability barriers to provider-based recall using an immunization information system; 3) strategies that facilitated recall initiation; and 4) recommendations for alternative approaches for conducting recall. METHODS: In 2008, 11 practices received training on the automatic recall function in the Colorado Immunization Information System (CIIS) for both infants and adolescents. The 2-hour computer-based training provided an opportunity for attendees to run real-time recall reports with CIIS staff assistance. Eight months later, key informant interviews were conducted with 24 providers and staff from these practices. RESULTS: Eight months after training, only 4 of 11 practices had implemented recall using CIIS: 3 practices recalled children ≤2 years of age, and 1 practice recalled adolescent girls for human papillomavirus vaccine. Initiation barriers included lack of awareness of baseline immunization rates, distrust in the accuracy of CIIS-generated data, and perceived difficulties recalling adolescents. Having unrealistic expectations about recall effectiveness was a barrier to sustainability. Strategies that facilitated recall included having a dedicated staff person for recall efforts and recalling children ≤2 years of age. Most key informants viewed population-based recall conducted by public health departments or schools as an acceptable alternative to provider-based recall. CONCLUSIONS: Even with a promising tool to assist pediatric offices, implementing provider-based recall is challenging for pediatric practices. Given existing barriers, providers expressed support for alternative recall methods.