Using classification and regression tree analysis to explore parental influenza vaccine decisions.

BACKGROUND AND OBJECTIVES: Influenza poses a public health threat for children and adults. The CDC recommends annual influenza vaccination for children <18 years, yet vaccine uptake remains low for children (57.9%) and adults (37.1%). Given that parental decision-making is key in childhood vaccine uptake, there is a critical need to understand vaccine hesitancy among parents who decide not to vaccinate their children. This study aims to explore predictors of children's influenza vaccine status given parental vaccination status and examine the factors that contribute to concordance or discordance between parental and children's vaccine uptake. METHODS: Classification and regression tree (CART) analyses were used to identify drivers of parental decisions to vaccinate their children against influenza. Hierarchy and interactions of these variables in predicting children's vaccination status were explored. RESULTS: From a nationally representative sample of non-Hispanic Black and White parents who completed an online survey (n = 328), the main factors influencing parents' decisions to vaccinate their children were vaccine behavior following physician recommendation, knowledge of influenza recommendations for children, influenza vaccine confidence and disease risk. Among unvaccinated parents, the greatest concordance was observed among parents who usually do not get vaccinated following physician recommendation and had lower knowledge of recommendations for influenza vaccination for children. The greatest discordance was observed among unvaccinated parents who had lower hesitancy about recommended vaccines. CONCLUSIONS: Understanding drivers of parental decisions to vaccinate themselves and their children can provide insights on health communication and provider approaches to increase influenza vaccine coverage and prevent influenza related mortality.

Home remedy use and influenza vaccination among African American and white adults: An exploratory study.

Racial disparities in influenza vaccination persist between African American and White adults. It is critical to explore the reasons behind this disparity, which may be linked to the use of "folk" or home remedies for illness prevention and treatment. For this study, The GfK Group was contracted to conduct a nationally-representative survey (n = 819 African American and 838 White respondents). Respondents were asked about behaviors, attitudes, and risk perception related to the influenza vaccine, as well as frequency of home remedy use. Results were analyzed using adjusted logistic regression with 95% confidence intervals. In comparison to those who never use home remedies, those who use home remedies often or almost always were less likely to get vaccinated for influenza (respectively, OR = 0.70, CI 0.49, 0.99; OR = 0.27, CI 0.15, 0.49), less likely to be in favor of the vaccine (OR = 0.47, CI 0.33, 0.67; OR = 0.19, CI 0.10, 0.34), less likely to trust the vaccine (OR = 0.42, CI 0.29, 0.61; OR = 0.34, CI 0.20, 0.61), and more likely to perceive higher risk of vaccine side effects (OR = 1.79, CI 1.19, 2.68; OR = 4.00, CI 2.38, 6.73). These associations did not vary by race. Home remedy users may hold negative views toward the influenza vaccine, such that a combination of little trust in the vaccine process, and overestimation of risk associated with the vaccine itself, may contribute to vaccine refusal. Health care professionals can use these findings to tailor advice toward individuals with a preference for home remedy use to allay fears and correct misconceptions surrounding influenza and its vaccine.

Measuring vaccine hesitancy, confidence, trust and flu vaccine uptake: Results of a national survey of White and African American adults.

INTRODUCTION: Vaccine hesitancy (VH) has emerged as a factor in vaccine delay and refusal yet the measurement of the constructs within vaccine hesitancy remains a challenge. Outstanding questions include; should VH be measured as an attitude or a behavior? What is the role of key constructs including confidence, complacency, and convenience? What is the role of trust? Should measures be general or vaccine specific? Furthermore, much of the research has centered on parental acceptance of vaccines for their children. METHODS: In March of 2015, we contracted with the GfK Group to conduct a nationally representative survey with 819 African American and 838 White, US born adults. Measures include general vaccine hesitancy and confidence, trust, and influenza vaccine specific measures of hesitancy, confidence and trust. RESULTS: Factor analysis yielded a bi-factor structure for both general vaccine hesitancy and flu vaccine specific hesitancy. Greater hesitancy, both in general and specific to the flu vaccine, was associated with lower vaccine uptake. In the flu vaccine specific model, greater confidence was associated with higher vaccine uptake. Trust remained distinct from vaccine confidence in both the general and flu vaccine specific models. CONCLUSIONS: Clearly, there is value in the utilization of general vaccine hesitancy and confidence measures, as well as vaccine specific measures. Trust continues to provide additional insights apart of vaccine confidence and remains an important factor for inclusion in future research. Our set of measures can be tested and validated with other populations and applied to other vaccines for adults and children.

"You don't trust a government vaccine": Narratives of institutional trust and influenza vaccination among African American and white adults.

Vaccine confidence depends on trust in vaccines as products and trust in the system that produces them. In the US, this system consists of a complex network connecting pharmaceutical companies, government agencies, and the healthcare system. We explore narratives from White and African American adults describing their trust in these institutions, with a focus on influenza vaccine. Our data were collected between 2012 and 2014 as part of a mixed-methods investigation of racial disparities in influenza immunization. We interviewed 119 adults, primarily in Maryland and Washington, DC, in three stages utilizing semi-structured interviews (12), focus groups (9, n = 91), and in-depth interviews (16). Analysis was guided by grounded theory. Trust in institutions emerged as a significant theme, with marked differences by race. In 2018, we contextualized these findings within the growing scholarship on trust and vaccines. Most participants distrusted pharmaceutical companies, which were viewed to be motivated by profit. Trust in government varied. Whites described implicit trust of federal institutions but questioned their competency. African Americans were less trusting of the government and were more likely to doubt its motives. Trust in institutions may be fragile, and once damaged, may take considerable time and effort to repair.

Social media use and influenza vaccine uptake among White and African American adults.

Influenza vaccination rates in the U.S. remain low at 41% among adults over 18 years according to the Centers for Disease Control and Prevention's 2016 data. Reasons for the low rate vary and include factors such as risk perception, vaccine hesitancy, and access to health care. This cross-sectional study sought to examine the relationship between social media use and influenza vaccine uptake among a sample of White and African Americans over 18 years of age. Using bivariate, and unadjusted and adjusted logistic regression tests, this study examined the relationship among social media use, social media as a source of health information, and influenza vaccination status in 2015. Our results indicate that users of Twitter (OR4.41, 95%CI: 1.43-13.60) and Facebook (OR 1.66, 95%CI: 1.01-2.72) as sources of health information were more likely to be vaccinated in comparison to users who do not use Twitter or Facebook as a source of health information. These findings have implications for the potential of using social media platforms to disseminate influenza vaccine information and encourage users to get vaccinated annually.

Breaking down the monolith: Understanding flu vaccine uptake among African Americans.

Black adults are significantly less likely to be immunized for seasonal influenza when compared to Whites. This persistent disparity contributes to increased influenza-related morbidity and mortality in the African American population. Most scholarship on vaccine disparities has compared Whites and Blacks. Employing Public Health Critical Race Praxis, this study seeks to shift the focus to explore differences within the Black population. Utilizing a nationally-representative 2015 survey of US Black adults (n = 806), we explore differences by gender, age, income, and education across vaccine-related measures (e.g., perceived risk, knowledge, attitudes) and racial factors (e.g. racial salience, racial fairness, perceived discrimination). We also explore differences by vaccine behavior in the past five years among those who vaccinate every year, most years but not all, once or twice, and never. Greater frequency of flu vaccine uptake was associated with better self-reported vaccine knowledge, more positive vaccine attitudes, more trust in the flu vaccine and the vaccine process, higher perceived disease risk, lower perceived risk of vaccine side effects, stronger subjective and moral norms, lower general vaccine hesitancy, higher confidence in the flu vaccine, and lower perceived barriers. Logistic regression results highlighted other significant differences among the groups, emphasizing areas to target for improved vaccination rates. We find great diversity within the Black community related to influenza immunization decisions, highlighting the need to "break down the monolith" in future research.

The influence of social norms on flu vaccination among African American and White adults.

Adult influenza vaccination rates remain suboptimal, particularly among African Americans. Social norms may influence vaccination behavior, but little research has focused on influenza vaccine and almost no research has focused on racially-specific norms. This mixed methods investigation utilizes qualitative interviews and focus groups (n = 118) and national survey results (n = 1643) to assess both descriptive and subjective norms surrounding influenza vaccination. Qualitative results suggest a perceived descriptive norm that 'about half' of the population gets vaccinated. Participants describe differing norms by race and vaccine behavior. Quantitative results confirm a perceived descriptive norm that 40-60% of the population gets vaccinated. Both African Americans and Whites accurately identified race-specific vaccination rates relative to the general population. Individuals who report that a majority of people around them want them to be vaccinated were significantly more likely to be vaccinated, suggesting subjective norms are influential for both White and African American adults. While perceived descriptive norms are somewhat accurate (mirroring the actual influenza vaccination rate), emphasizing a suboptimal vaccination rate may not be beneficial. Health promotion efforts, particularly those targeting African Americans, may benefit from focusing on subjective norms and encouraging friends and family members to talk about the benefits of influenza vaccination.

Determinants of influenza vaccination among high-risk Black and White adults.

BACKGROUND: Adults with chronic conditions are at much greater risk of influenza-related morbidity and mortality, yet flu vaccine uptake remains suboptimal. Research focused on the high-risk population has been limited, particularly related to racial disparities in vaccination. We explore a broad range of demographic, racial, and psychosocial factors to identify predictors of vaccination among high-risk adults, with a focus on identify differences between Black and White adults. METHODS: We conducted an online survey in March 2015, utilizing international research firm GfK's KnowledgePanel, for a nationally representative sample of Black and White adults (≥18, USA) and limited analysis adults with high-risk of influenza-related complications. Using two-way ANOVA, we assessed demographic, racial, and psychosocial predictors across vaccine uptake in the past five years and across racial group. RESULTS: 424 (52.2%) Black and 388 (47.8%) White respondents with high-risk complications completed the survey. 383 (47.3%) reported vaccination annually, 99 (12.2%) most years, 104 (12.9%) once/twice, and 223 (27.6%) never.ANOVA confirmed significant differences in vaccine behavior for most demographic predictors (except education), all racial factors (including racial fairness, experiences of discrimination, etc.), and most psychosocial factors (including vaccine attitudes, trust in the vaccine, etc.). ANOVA confirmed significant differences for most factors by race. We observed significant interaction effects between race and vaccine behavior for subjective social status, access to medical care, knowledge of vaccine recommendations, vaccine attitudes, perceived side effect risks, descriptive norms, subjective norms, flu vaccine hesitancy, and flu vaccine confidence, thus implying racial differences in the connection between vaccine uptake and key demographic, racial, and psychosocial factors. CONCLUSIONS: This study provides a novel examination of flu vaccine behavior among high-risk Blacks and Whites that identified factors influencing vaccine uptake.We found significant differences by race. Health care professionals can use this information to more effectively target high-risk adults during flu season.

Determinants of trust in the flu vaccine for African Americans and Whites.

Trust is thought to be a major factor in vaccine decisions, but few studies have empirically tested the role of trust in adult immunization. Utilizing a 2015 national survey of African American and White adults (n = 1630), we explore multiple dimensions of trust related to influenza immunization, including generalized trust, trust in the flu vaccine, and trust in the vaccine production process. We find African Americans report lower trust than Whites across all trust measures. When considering demographic, racial, and ideological predictors, generalized trust shows statistically significant effects on both trust in the flu vaccine and trust in the vaccine process. When controlling for demographic, racial, and ideological variables, higher generalized trust was significantly associated with higher trust in the flu vaccine and the vaccine process. When controlling for generalized trust, in addition to the baseline covariates, psychosocial predictors (i.e. risk perception, social norms, knowledge) are significant predictors of trust in flu vaccine and trust in the vaccine process, with significant differences by race. These findings suggest that trust in vaccination is complex, and that significant differences in trust between White and African American adults may be contributing to disparities in influenza immunization.

The Role of Risk Perception in Flu Vaccine Behavior among African-American and White Adults in the United States.

Seasonal flu vaccination rates are low for U.S. adults, with significant disparities between African and white Americans. Risk perception is a significant predictor of vaccine behavior but the research on this construct has been flawed. This study addressed critical research questions to understand the differences between African and white Americans in the role of risk perception in flu vaccine behavior: (1) What is the dimensionality of risk perception and does it differ between the two races?  (2) Were risk perceptions of white and African-American populations different and how were sociodemographic characteristics related to risk for each group? (3) What is the relation between risk perception and flu vaccine behaviors for African Americans and whites? The sample, drawn from GfK's Knowledge Panel, consisted of 838 whites and 819 African Americans. The survey instrument was developed from qualitative research. Measures of risk perception included cognitive and emotional measures of disease risk and risk of side effects from the vaccine. The online survey was conducted in March 2015. Results showed the importance of risk perception in the vaccine decision-making process for both racial groups. As expected, those who got the vaccine reported higher disease risk than those who did not. Separate cognitive and emotional factors did not materialize in this study but strong evidence was found to support the importance of considering disease risk as well as risk of the vaccine. There were significant racial differences in the way risk perception predicted behavior.

Exploring racial influences on flu vaccine attitudes and behavior: Results of a national survey of White and African American adults.

INTRODUCTION: Racial disparities in adult flu vaccination rates persist with African Americans falling below Whites in vaccine acceptance. Although the literature has examined traditional variables including barriers, access, attitudes, among others, there has been virtually no examination of the extent to which racial factors including racial consciousness, fairness, and discrimination may affect vaccine attitudes and behaviors. METHODS: We contracted with GfK to conduct an online, nationally representative survey with 819 African American and 838 White respondents. Measures included risk perception, trust, vaccine attitudes, hesitancy and confidence, novel measures on racial factors, and vaccine behavior. RESULTS: There were significant racial differences in vaccine attitudes, risk perception, trust, hesitancy and confidence. For both groups, racial fairness had stronger direct effects on the vaccine-related variables with more positive coefficients associated with more positive vaccine attitudes. Racial consciousness in a health care setting emerged as a more powerful influence on attitudes and beliefs, particularly for African Americans, with higher scores on racial consciousness associated with lower trust in the vaccine and the vaccine process, higher perceived vaccine risk, less knowledge of flu vaccine, greater vaccine hesitancy, and less confidence in the flu vaccine. The effect of racial fairness on vaccine behavior was mediated by trust in the flu vaccine for African Americans only (i.e., higher racial fairness increased trust in the vaccine process and thus the probability of getting a flu vaccine). The effect of racial consciousness and discrimination for African Americans on vaccine uptake was mediated by perceived vaccine risk and flu vaccine knowledge. CONCLUSIONS: Racial factors can be a useful new tool for understanding and addressing attitudes toward the flu vaccine and actual vaccine behavior. These new concepts can facilitate more effective tailored and targeted vaccine communications.

Public acceptance of peramivir during the 2009 H1N1 influenza pandemic: implications for other drugs or vaccines under emergency use authorizations.

OBJECTIVE: The Centers for Disease Control and Prevention estimated that up to 88 million H1N1 influenza cases, 398,000 hospitalizations, and up to 18,050 related deaths, including significant racial and ethnic disparities, occurred between April 2009 and March 13, 2010. The Food and Drug Administration (FDA) approved emergency use authorizations (EUAs), which allowed the distribution of unapproved drugs or the off-label use of approved drugs. In late 2009, peramivir was granted an EUA for patients with severe disease. This study examined factors associated with willingness to take peramivir. METHODS: In 2010 we conducted a nationally representative survey with 2079 respondents randomly drawn from the Knowledge Networks research panel. Our completion rate was 56%. Respondents received information about peramivir from a fact sheet and then answered questions about their willingness to take the drug. RESULTS: Overall, 48% of participants indicated that they would probably or definitely take peramivir. Seventy-nine percent definitely would take the drug if their doctor recommended it and there were no alternative treatments. There were significant racial differences in willingness. The term experimental to refer to the drug decreased willingness to accept peramivir among both whites and blacks. CONCLUSIONS: Trust in the FDA was important for peramivir acceptance. Particular care must be taken to ensure that patients and their families understand the complex nature of EUA drugs. Lessons learned can inform communication about future EUAs. (Disaster Med Public Health Preparedness. 2015;9:166-174).

Trust during the early stages of the 2009 H1N1 pandemic.

Distrust of the government often stands in the way of cooperation with public health recommendations in a crisis. The purpose of this article is to describe the public's trust in government recommendations during the early stages of the H1N1 pandemic and to identify factors that might account for these trust levels. The authors surveyed 1,543 respondents about their experiences and attitudes related to H1N1 influenza between June 3, 2009, and July 6, 2009, during the first wave of the pandemic using the Knowledge Networks online panel. This panel is representative of the U.S. population and uses a combination of random digit dialing and address-based probability sampling frames covering 99% of the U.S. household population to recruit participants. To ensure participation of low-income individuals and those without Internet access, Knowledge Networks provides hardware and access to the Internet if needed. Measures included standard demographics, a trust scale, trust ratings for individual spokespersons, involvement with H1N1, experience with H1N1, and past discrimination in health care. The authors found that trust of government was low (2.3 out of 4) and varied across demographic groups. Blacks and Hispanics reported higher trust in government than did Whites. Of the spokespersons included, personal health professionals received the highest trust ratings and religious leaders the lowest. Attitudinal and experience variables predicted trust better than demographic characteristics. Closely following the news about the flu virus, having some self-reported knowledge about H1N1, self-reporting of local cases, and previously experiencing discrimination were the significant attitudinal and experience predictors of trust. Using a second longitudinal survey, trust in the early stages of the pandemic predicted vaccine acceptance later but only for White, non-Hispanic individuals.

Determinants of Parental Acceptance of the H1N1 Vaccine.

Although designated as a high-risk group during the 2009-2010 H1N1 pandemic, only about 40% of U.S. children received the vaccine, a relatively low percentage compared with high-risk groups in seasonal influenza, such as the elderly, whose vaccine rates typically top 70%. To better understand parental decision making and predictors of acceptance of the H1N1 vaccine, we examined data from a representative national sample of parents (n = 684), using the health belief model as a framework. The most important predictors of vaccine acceptance were "cues to action" at multiple levels, from intrapersonal to mass communication, including the influence of friends, family, the media, and modeling by the Obama family; costs and benefits and self-efficacy were also significant predictors of vaccine acceptance. Higher perceived levels of H1N1 risk were not associated with vaccine uptake. Results suggest that traditional measures of perceived risk may not account for the cost-benefit analysis inherent in vaccine decision making, and that messages designed to emphasize disease risk may be ineffective. The authors recommend emphasizing cues to action that support norming and modeling of vaccine acceptance.

Training meals on wheels volunteers as health literacy coaches for older adults.

Homebound older adults constitute a "hardly reached" population with respect to health communication. Older adults also typically suffer from health literacy challenges, which put them at increased risk of adverse health outcomes. Suboptimal interactions with providers are one such challenge. Interventions to improve interactive health literacy focus on training consumers/patients in question preparation and asking. Meals on Wheels volunteers are uniquely suited to coach their clients in such interaction strategies. Seventy-three Meals on Wheels volunteers participated in workshops to train as health literacy coaches. The 3- to 4-hour workshops included units on communicating with older adults, on the nature of health literacy, and on the process of interactive health literacy coaching. Participants viewed and discussed videos that modeled the targeted communication behaviors for older adult patients interacting with physicians. They role-played the coaching process. After 9 months, coaches participated in a "booster" session that included videos of ideal coaching practices. Evaluation questionnaires revealed that participants had favorable reactions to the workshops with respect to utility and interest. They especially appreciated learning communication skills and seeing realistic videos. A measure of knowledge about the workshop material revealed a significant increment at posttest. Fidelity of coaching practices with respect to workshop curriculum was confirmed. This training in interactive health literacy for community-based lay volunteers constitutes one way to implement the National Action Plan to Improve Health Literacy for one "hardly reached" population. An online tool kit containing all workshop materials is available.

Exploring communication, trust in government, and vaccination intention later in the 2009 H1N1 pandemic: results of a national survey.

With the growing recognition of the critical role that risk communication plays in a public health emergency, a number of articles have provided prescriptive best practices to enhance such communication. However, little empirical research has examined perceptions of the quality of communication, the impact of uncertainty on changing communication, use of information sources, and trust in specific government spokespersons. Similarly, although there is significant conceptual focus on trust and communication as important in vaccination intent and acceptance, little research has explored these relationships empirically. We conducted an online survey in late January 2010 with a nationally representative sample (N=2,079) that included Hispanic and African American oversamples. The completion rate was 56%. We found that public health officials were the most trusted spokespersons, with President Obama being the most highly trusted elected official. Demographic variables, including race, accounted for 21% of the variance in trust of the president. Perceptions of the quality of communication were high, including significant understanding of uncertainty and appreciation for officials' openness about evolving information. Other factors that contributed to vaccination acceptance were quality of communication, closely following the news, and confidence in the vaccine because of a role model effect of the Obama daughters' immunizations; these factors significantly increased trust in government actions. Because the challenges of communication often vary over the course of a pandemic, there is a consistent need to pay close attention to both communication content and delivery and prepare public health officials at all levels to be effective communicators.

Cognitive and emotional health risk perceptions among people living in poverty.

Many theories of risk perception and health behavior examine cognitive dimensions of risk (i.e., perceived susceptibility or severity) but not emotional dimensions. To address this gap, the authors examined the emotional component of risk perception (as worry) and its relation to cognitive assessments of risk, self-efficacy and response efficacy, and health protective action. Although people in poverty are at high risk for many health conditions, little is known about how concerned they are about these conditions or how their risk perceptions influence health actions. African Americans and Whites with incomes≤$35,000 were surveyed (N=431). Participants reported their worry level for 10 health risks. Among their highest worry risks, they identified the risk they took the most action and the risk they took the least action to prevent. Worry was low or moderate for each health risk and chronic conditions were of the most concern. For high- and low-action risks, response efficacy moderated the relation between cognitive risk perception and health protective action. For low-action risks, decisions to act were affected independently by cognitive and emotional responses. The results support the Risk Perception Attitude Framework and indicate the importance of using cognitive and emotional dimensions of risk in behavior change models.

The social ecological model as a framework for determinants of 2009 H1N1 influenza vaccine uptake in the United States.

Research on influenza vaccine uptake has focused largely on intrapersonal determinants (perceived risk, past vaccine acceptance, perceived vaccine safety) and on physician recommendation. The authors used a social ecological framework to examine influenza vaccine uptake during the 2009 H1N1 pandemic. Surveying an adult population (n = 2,079) in January 2010 with significant oversamples of Blacks and Hispanics, this study found that 18.4% (95% confidence interval = 15.6-21.5) had gotten the 2009 H1N1 vaccine. Variables at each level of the social ecological model were significant predictors of uptake as well as of intent to get the vaccine. The intrapersonal level explained 53%, the interpersonal explained 47%, the institutional level explained 34%, and the policy and community levels each explained 8% of the variance associated with vaccine uptake. The levels together explained 65% of the variance, suggesting that interventions targeting multiple levels of the framework would be more effective than interventions aimed at a single level.

The impact of workplace policies and other social factors on self-reported influenza-like illness incidence during the 2009 H1N1 pandemic.

OBJECTIVES: We assessed the impact of social determinants of potential exposure to H1N1--which are unequally distributed by race/ethnicity in the United States--on incidence of influenza-like illness (ILI) during the 2009 H1N1 pandemic. METHODS: In January 2010 we surveyed a nationally representative sample (n = 2079) of US adults from the Knowledge Networks online research panel, with Hispanic and African American oversamples. The completion rate was 56%. RESULTS: Path analysis examining ILI incidence, race, and social determinants of potential exposure to H1N1 demonstrated that higher ILI incidence was related to workplace policies, such as lack of access to sick leave, and structural factors, such as number of children in the household. Hispanic ethnicity was related to a greater risk of ILI attributable to these social determinants, even after we controlled for income and education. CONCLUSIONS: The absence of certain workplace policies, such as paid sick leave, confers a population-attributable risk of 5 million additional cases of ILI in the general population and 1.2 million cases among Hispanics. Federal mandates for sick leave could have significant health impacts by reducing morbidity from ILI, especially in Hispanics.