Individual Preferences for Child and Adolescent Vaccine Attributes: A Systematic Review of the Stated Preference Literature

A latent class analysis of factors influencing preferences for infant respiratory syncytial virus (RSV) preventives among pregnant people in the United States

A maternal vaccine and long-acting monoclonal antibody (mAb) were recently approved to protect infants against respiratory syncytial virus (RSV). We identified subgroups of pregnant people with different preferences for RSV preventives and respondent characteristics associated with subgroup membership. An online survey, including a discrete choice experiment (DCE), was conducted among US pregnant people. RSV preventive attributes included effectiveness, duration of protection during RSV season, injection recipient/timing, preventive type (vaccine or mAb), and type of visit required to receive injection. In DCE choice tasks, pregnant people selected between two hypothetical preventive profiles with varying attribute-levels and a no-preventive option. Logistic regression, including latent class analysis (LCA), was used to analyze the data. Of 992 pregnant people (mean age: 30.0 years), 60.3% were expecting their second/later birth. LCA identified three preference subgroups: 'Effectiveness' (preventive choice mostly driven by increases in effectiveness; 51.4% class membership probability), 'Season' (preventive choice mostly driven by improvement in duration of protection during the RSV season; 39.2% class membership probability), and 'No Preventive' (frequently chose no-preventive option; 9.4% class membership probability). 'Effectiveness' and 'Season' preferred maternal vaccine over mAb; mAb was preferred by 'No Preventive.' Perceiving RSV as serious for infants, higher health literacy, and lower household income were associated with 'Effectiveness.' Perceiving RSV as serious for pregnant people was associated with 'Season.' Perceiving RSV to not be serious for pregnant people and not being employed were associated with 'No Preventive.' Subgroups of pregnant people vary in preferences for RSV preventives. Most pregnant people preferred a maternal vaccine, although some may be more willing to accept alternative preventive options.

Adolescent-Preferred financial incentives to promote type 1 diabetes Self-Care: A discrete choice experiment

AIMS

This study aimed to quantify preferences for the characteristics of a financial incentives program that would motivate adolescent engagement in type 1 diabetes (T1D) self-care.

METHOD

We performed a discrete choice experiment with 12-18 year-olds with T1D from two pediatric hospital endocrinology clinics (n = 317). We identified key attributes of incentives: (1) monthly value of the reward, (2) payment structure, and (3) difficulty of incentivized behaviors. In twelve choice questions, adolescents chose the incentive option from a pair of profiles that was more likely to motivate them to increase adherence to recommended self-care. Options presented were tailored to adolescents' T1D technology use and perceived difficulty of completing each behavior. We analyzed data using a conditional logit model.

RESULTS

The value of the reward accounted for 60.8% of preferences. Adolescents were willing to accept lower value rewards when incentive payments used positive vs. negative reinforcement (-$10.88 (95% CI: -$12.60, -9.24)) and preferred higher incentives for performing hard vs. easier behaviors (+$14.92 (95% CI: +$12.66, +$17.28)).

CONCLUSIONS

Stated preferences can inform intervention design. Future research will evaluate the external validity of the discrete choice experiment-informed intervention design by assessing adolescent health and behavioral outcomes in a randomized controlled trial.

Nurses' preferences regarding MenACWY conjugate vaccines attributes: a discrete choice experiment in Spain

OBJECTIVES

Immunisation against preventable diseases as meningitis is crucial from a public health perspective to face challenges posed by these infections. Nurses hold a great responsibility for these programs, which highlights the importance of understanding their preferences and needs to improve the success of campaigns. This study aimed to investigate nurses' preferences regarding Meningococcus A, C, W, and Y (MenACWY) conjugate vaccines commercialised in Spain.

STUDY DESIGN

A national-level discrete choice experiment (DCE) was conducted.

METHODS

A literature review and a focus group informed the DCE design. Six attributes were included: pharmaceutical form, coadministration evidence, shelf-life, package contents, single-doses per package, and package volume. Conditional logit models quantified preferences and relative importance (RI).

RESULTS

Thirty experienced primary care nurses participated in this study. Evidence of coadministration with other vaccines was the most important attribute (RI = 43.78%), followed by package size (RI = 22.17%), pharmaceutical form (RI = 19.07%), and package content (RI = 11.80%). There was a preference for evidence of coadministration with routine vaccines (odds ratio [OR] = 2.579, 95% confidence interval [95%CI] = 2.210-3.002), smaller volumes (OR = 1.494, 95%CI = 1.264-1.767), liquid formulations (OR = 1.283, 95%CI = 1.108-1.486) and package contents including only vial/s (OR = 1.283, 95%CI = 1.108-1.486). No statistical evidence was found for the remaining attributes.

CONCLUSIONS

Evidence of coadministration with routine vaccines, easy-to-store packages, and fully liquid formulations were drivers of nurses' preferences regarding MenACWY conjugate vaccines. These findings provide valuable insights for decision-makers to optimize current campaigns.

Patient versus physician preferences for lipid-lowering drug therapy: A discrete choice experiment

BACKGROUND

The emergence of proprotein convertase subtilisin/kexin type 9 inhibitors offered dyslipidemia patients an alternative to statins for lipid-lowering treatment. Understanding patient and physician preferences for lipid-lowering drugs may promote shared decision-making and improve treatment outcomes.

METHODS

This study utilized an online discrete choice experiment (DCE) to assess the relative importance (RI) of six attributes related to lipid-lowering drugs, including frequency of administration, mode of administration, reduction of low-density lipoprotein cholesterol (LDL-C) level, risk of myopathy, risk of liver damage, and out-of-pocket monthly cost. Respondents were recruited from dyslipidemia patients and cardiovascular physicians in China. A mixed logit model and latent class analysis were employed to estimate the preference coefficient, marginal willingness to pay (mWTP), and RI of attributes. Ethical approval has been obtained for this study.

RESULTS

A total of 708 patients and 507 physicians participated in the survey. Patients prioritized the 'risk of liver damage' (RI = 23.6%) with 'mode of administration' (RI = 19.2%) and 'frequency of administration' (RI = 18.8%) following closely. Contrarily, physicians prioritized the 'reduction of LDL-C level' (RI = 33.5%), followed by 'risk of liver damage' (RI = 26.0%) and 'risk of myopathy' (RI = 16.1%). Patients placed a higher value on 'frequency of administration' (p < .001) and 'mode of administration' (p < .001) compared to physicians, while physicians valued 'reduction of LDL-C level' (p < .001) and 'risk of myopathy' (p = .012) more than patients. Physicians exhibited higher mWTP than patients for all attributes except frequency and mode of administration. The LCA revealed three distinct patient classes: focus on oral administration, focus on hepatic safety and frequency and focus on hepatic safety and cost. Likewise, three physician classes were identified: frequency-insensitive, efficacy-focused and safety-focused.

CONCLUSIONS

The preferences for lipid-lowering drug therapy differed between patients and physicians in China. Physicians should take into account patients' preferences and provide personalized treatment when they formulate lipid-lowering treatment plans.

PATIENT OR PUBLIC CONTRIBUTION

Patients participated in the questionnaire design process. They engaged in a focus group discussion to determine attributes and levels and also participated in a pilot survey to assess the comprehensibility of the questionnaires. Additionally, patients were involved in the DCE survey to express their preferences. The findings of patient preference for lipid-lowering drug therapy will promote shared decision-making and optimize the treatment regimen.

Vaccine decision making in New Zealand: a discrete choice experiment

BACKGROUND

Vaccine hesitancy is a significant threat to global health. A key part of addressing hesitancy is to ensure that public health messaging prioritises information that is considered important to the public. This study aimed to examine how different vaccine characteristics affect public preferences for vaccines in New Zealand, what trade-offs they are willing to make between different vaccine characteristics, and how their preferences are affected by their vaccine-related conspiracy beliefs and COVID-19 vaccination status.

METHODS

An online discrete choice experiment (DCE) was designed to elicit individual preferences about vaccines using the 1000minds platform. Members of the general population of New Zealand aged ≥ 18 years were invited to complete the DCE. Participants were asked to indicate their preference between two options showing different combinations of vaccine characteristics. Data on sociodemographic characteristics were collected. Beliefs were measured using the vaccine conspiracy beliefs scale (VCBS) with scores ≥ 19 indicating strong vaccine-related conspiracy beliefs. The DCE was analysed using the PAPRIKA method (Potentially All Pairwise RanKings of all possible Alternatives) and preferences compared between respondents with high versus low VCBS scores and vaccinated versus unvaccinated respondents for COVID-19.

RESULTS

A total of 611 respondents from 15 regions completed the DCE. Mean (SD) age was 45.9 (14.7) years with most having had 2 or more doses of the coronavirus vaccine (86%). Mean (SD) VCBS score was 18.5 (12.4) indicating moderate vaccine-related conspiracy beliefs. Risk of severe adverse effects was the most highly valued vaccine characteristic, followed by vaccine effectiveness and duration of protection. Vaccine origin and route of administration were ranked least important. Respondents scoring high on the VCBS placed less value on the effectiveness of vaccines but greater value on development time and total number of doses (p < 0.001). COVID-19 unvaccinated respondents ranked development time and total number of doses more highly than those vaccinated respondents (p < 0.001).

CONCLUSIONS

Risk of severe adverse effects, vaccine effectiveness and duration of protection were rated by the New Zealand public as the top three most important vaccine characteristics. This information is important for informing public health messaging to promote vaccine uptake and inform vaccine decision-making.

Parental preferences for rotavirus vaccination for their children under 5 years old in China: A discrete choice experiment

Rotavirus vaccination is the most effective means to prevent rotavirus gastroenteritis, but its coverage in China is not ideal. We aimed to explore parental preferences for rotavirus vaccination for their children under 5years old to improve vaccination coverage. A Discrete Choice Experiment was conducted online on 415 parents with at least one child under 5years old in 3 cities. Five attributes including vaccine effectiveness, protection duration, risk of mild side-effects, out-of-pocket costs, and time required for vaccination were identified. Each attribute was set at three levels. Mixed-logit models were used to measure parental preferences and the relative importance of vaccine attributes. The optimal vaccination strategy was also explored. 359 samples were included in the analysis. The impacts of the vaccine attribute levels on vaccine choice were all statistically significant (p < .01), except for 1-hour vaccination time. The risk of mild side-effects was the most important factor influencing vaccination. The time required for vaccination was the least important attribute. The largest increase in vaccination uptake (74.45%) occurred with decreased the vaccine risk of mild side-effects from 1/10 to 1/50. The predicted vaccination uptake of the optimal vaccination scenario was 91.79%. When deciding about vaccination, parents preferred the rotavirus vaccination with lower risk of mild side-effects, higher effectiveness, longer protection duration, 2-hour vaccination time and lower cost. The authorities should support enterprises to develop vaccines with lower side-effects, higher effectiveness and longer protection duration in the future. We call for appropriate government subsidies for the rotavirus vaccine.

Preferences of pregnant women toward a future maternal Group B Streptococcus vaccine in China: A cross-sectional survey with a discrete choice experiment

Group B streptococcus (GBS) is a major cause of neonatal death worldwide. A GBS vaccine for pregnant women is under development and is expected to be available in the near future. The perceptions and preferences of pregnant women in China of GBS vaccines has not been investigated, and this study aimed to investigate pregnant women's awareness of GBS and their potential preferences for the GBS vaccine. A discrete choice experiment was conducted among pregnant women in hospitals from Shaanxi, Hunan, and Zhejiang provinces located in Western, Central, and Eastern China, respectively. A conditional logit model was used to analyze the data and calculate willingness to pay values and choice probabilities of different GBS vaccine programs. A total of 354 pregnant women were included in the final analysis, 45.8% of whom were willing to receive a GBS vaccine if it were licensed. Vaccine safety was the most important attribute of a future vaccine, while cost was the least important attribute. Compared with no vaccination, pregnant women had a strong preference for future GBS vaccination (ASC = 1.267, p < .001). Pregnant women's decisions were highly influenced by those of other pregnant women. Improving the safety, efficacy, and vaccination rate of the GBS vaccine in China is of great significance for future GBS vaccine development and vaccination. Compared to other variable options, the cost of a GBS vaccine was of the least importance among pregnant women in mainland China. These findings can inform public health policy decisions related to GBS vaccination in China.

What motivates adults to accept influenza vaccine? An assessment of incentives, ease of access, messaging, and sources of information using a discrete choice experiment

Seasonal influenza vaccination rates remain low, and contribute to preventable influenza cases, hospitalizations, and deaths in the US. While numerous interventions have been implemented to increase vaccine uptake, there is a need to determine which interventions contribute most to vaccine willingness, particularly among age groups with vaccination rates that have plateaued at suboptimal levels. This study aimed to quantify the relative effect of multiple interventions on vaccine willingness to receive influenza vaccine in three age groups using a series of hypothetical situations with different behavioral interventions. We assessed the relative impact of four categories of interventions: source of vaccine messages, type of vaccination messages, vaccination incentives, and ease of vaccine access using a discrete choice experiment. Within each category, we investigated the role of four different attributes to measure their relative contribution to willingness to be vaccinated by removing one option from each of the intervention categories. Among the 1,763 Minnesota residents who volunteered for our study, participants expressed vaccine willingness in over 80% of the scenarios presented. Easy access to drop-in vaccination sites had the greatest impact on vaccine willingness in all age groups. Among the younger age group, small financial incentives also contributed to high vaccine willingness. Our results suggest that public health programs and vaccination campaigns may improve their chances of successfully increasing vaccine willingness if they offer interventions preferred by adults, including facilitating convenient access to vaccination and offering small monetary incentives, particularly for young adults.

Perceptions and Cues to Action as Predictors of Nurses' Vaccination Intentions at Two Primary Health Care Facilities in Ghana

Uptake of hepatitis B vaccination by health care providers remains suboptimal in Ghana, although it is considered an effective strategy against the hepatitis B virus. This study aimed to identify the predictors of nurses' hepatitis B vaccination intentions at two municipal health care facilities in Ghana. A descriptive cross-sectional survey was adopted. A section of the health belief model-based questionnaire was administered to 181 nurses conveniently sampled from the two facilities. Data analysis was done using Statistical Product and Service Solutions software version 23.0. Frequencies and percentages were used to assess the demographic characteristics of participants. Pearson r coefficients were used to assess the intercorrelations between individual perceptions, and the cues to action on vaccination intentions. Simple and multiple regression was used to estimate the prediction of individual perceptions, and the cues to action on hepatitis B vaccination intentions of nurses. The findings showed that nurse-perceived benefits and cues to action were positive and significantly related to hepatitis B vaccination intentions of nurses (r = 0.14, P < 0.05; r = 0.17, P < 0.05). Perceived susceptibility and perceived barrier were negative and significantly related to vaccine intentions (r = -0.13, P < 0.05; r = -0.24, P < 0.01). Notably, perceived barrier predicted hepatitis B vaccination intentions (β = -0.22, t = -2.48, P = 0.01). Nurses' vaccination behavioral intentions were positive. It was recommended that perceived barriers to hepatitis B vaccination such as vaccination ineffectiveness, time constraints, high costs, and side effects should be addressed to increase nurses' vaccination uptake.

Societal Preferences for Meningococcal B Vaccination in Children: A Discrete Choice Experiment in Spain

INTRODUCTION

Immunization is the most effective strategy for the prevention of invasive meningococcal disease caused by Neisseria meningitidis serogroup B (MenB); however, parents need to weigh the risk-benefit and financial impact of immunizing their children against MenB in the absence of a national immunization program (NIP). This study aimed to explore societal preferences (of parents and pediatricians) regarding the attributes of a MenB vaccine in Spain.

METHODS

A discrete choice experiment (DCE) based on cross-sectional surveys was carried out to determine preferences. A literature review and scientific committee determined the six attributes related to the MenB vaccine included in the DCE: vaccination age, cost, duration, percentage of protection, adverse events probability, and expert/authority recommendation. Data were analyzed using a mixed logit model. Relative importance (RI) of attributes was calculated and compared between parents and pediatricians.

RESULTS

A total of 278 parents [55.8% female, mean age 40.4 (standard deviation, SD 7.3) years] and 200 pediatricians [73.0% female, mean age 45.8 (SD 12.9) years] answered the DCE. For parents, the highest RI was attributed to vaccine cost, expert/authority recommendation, and percentage of protection (26.4%, 26.1%, and 22.9%, respectively), while for pediatricians the highest RI was assigned to percentage of protection, expert/authority recommendation, and vaccination age (27.2%, 23.7%, and 22.6%, respectively). Significant differences between parents and pediatricians were found in the RI assigned to all attributes (p < 0.001), except for vaccine recommendation.

CONCLUSION

In the decision regarding MenB vaccination, cost was a driver in parental decision-making but had a low RI for pediatricians and, conversely, vaccination age was highly valued by pediatricians but was the attribute with least importance for parents. Despite these differences, expert/authority recommendation and percentage of protection were essential criteria for both groups. These results provide relevant information about MenB vaccination, highlighting the importance of considering societal preferences for NIP inclusion.

Parental refusal and hesitancy of vaccinating children against COVID-19: Findings from a nationally representative sample of parents in the U.S

The uptake rate of COVID-19 vaccines among children remains low in the U.S. This study aims to 1) identify sociodemographic and behavioral factors influencing parental refusal of vaccinating children, and 2) quantify the relative importance of vaccine characteristics in parental hesitancy of vaccinating children. An online survey was conducted from October to November 2021 among a probability-based, representative sample of 1456 parents with children under age 18. The survey included a discrete choice experiment asking parents to choose between two hypothetical COVID-19 vaccine alternatives with varying levels of characteristics in 10 hypothetical scenarios. Logistic regressions were used to estimate parental refusal (refused to choose any vaccine alternatives in all hypothetical scenarios) and random parameter logit regressions were used to estimate parental hesitancy (choice of vaccine alternatives depended on vaccine characteristics) of vaccinating children. About 20% parents refused to vaccinate children. The refusal is predicted by parents' sociodemographic characteristics, political orientation, vaccination status, and parents' and children's previous exposure with COVID-19. Among parents who were willing to consider vaccinating children, the most important vaccine characteristics are risk of severe side effects (31.2% relative importance) and effectiveness (30.7%), followed by protection duration (22.6%), local coverage (9.4%), and hospitalization rate of unvaccinated children (6.1%). Our findings imply that policymakers and public health professionals could develop outreach programs at community level to encourage specific subgroups and focus on vaccination depoliticization. Effectively communicating the low risk of severe side effects and high effectiveness of the vaccines may relieve some of the parental hesitancy.

Travelers' preferences for tick-borne encephalitis vaccination

BACKGROUND

This study aimed to quantify preferences and risk tolerance for a tick-borne encephalitis (TBE) vaccination.

RESEARCH DESIGN AND METHODS

A stated-preference survey instrument was administered to international travelers living in the United States to elicit preferences for a no-cost TBE vaccine when planning an international trip, conditional upon four different qualitative levels of endemic TBE risk.

RESULTS

The likelihood of choosing the vaccine increased with a destination's level of endemic risk. Most respondents (94%) would choose to receive the vaccine at the highest risk level presented in the survey (i.e. when multiple TBE cases among humans are reported year after year); 6% of the sample would choose not to receive the vaccine at any risk level. Respondents who engage in outdoor activities were twice as likely as the average respondent to choose vaccination rather than opting out of vaccination, and were one-third more likely than the average respondent to choose to receive the vaccine at the lowest risk level.

CONCLUSIONS

Respondents were highly interested in a TBE vaccine, assuming no cost, and most were willing to be vaccinated at all qualitative TBE risk levels. Respondents who participated in outdoor activities were more likely than the average respondent to choose the vaccine.

Public Preferences and Willingness to Pay for a COVID-19 Vaccine in Iran: A Discrete Choice Experiment

BACKGROUND AND OBJECTIVE

The coronavirus disease 2019 (COVID-19) pandemic is a major international threat and vaccination is the most robust strategy to terminate this crisis. It is helpful for policymakers to be aware of community preferences about vaccines. The present study aims to investigate the public's preferences and willingness to pay for the COVID-19 vaccine in Iran.

METHODS

This research is a cross-sectional study performed using a discrete choice experiment for a sample of the public population of several provinces of Iran in 2021. The samples were divided into two groups: one group expressed their preferences regarding the vaccine's attributes, and another group expressed their preferences regarding prioritizing individuals to get the vaccine. The discrete choice experiment design included five attributes including effectiveness, risk of severe complications, price, location of vaccine production, and duration of protection related to preferences for vaccine selection and six attributes including age, underlying diseases, employment in the healthcare sector, the rate of virus spread, the necessary job, and cost to the community related to preferences for prioritizing individuals to get the vaccine. A total of 715 individuals completed the questionnaire. The conditional logit regression model was used to analyze the discrete choice experiment data. Willingness to pay for each attribute was also calculated.

RESULTS

The willingness to pay for the COVID-19 vaccine with 90% (70%) efficacy, the risk of severe complications for 1 (5) person per one million people, imported (domestic) vaccine, and 24-month (12-month) duration of protection attributes was about US$71 (US$37). The preference for vaccination for respondents was enhanced by increasing the efficacy and the duration of vaccine protection and decreasing complications and costs. The likelihood of prioritizing individuals to get a vaccination was increased for a person with an underlying disease, employment in the healthcare sector, the necessary job for the community, the high potential for virus spread in the community, and the high cost of death to the community. The age variable was not statistically significant for prioritizing individuals to get the vaccine.

CONCLUSIONS

In the setting of the COVID-19 vaccination program, the public's preferences identified in this study should be considered. The obtained results provide useful information for policymakers to identify individual and social values for an appropriate vaccination strategy.

Preferences for attributes of long-term care in dementia: a scoping review of multi-criteria decision analyses

Aim

Long-term care considerations for persons with dementia are complex. Multi-criteria decision analysis (MCDA) methods are increasingly used to support healthcare decisions. The objective of this scoping review was to identify and analyze published MCDAs in which preferences for living and care concepts for persons with dementia are determined.

Subject and methods

A literature search was conducted in PubMed, EMBASE, Web of Science, and Google Scholar in October 2021. Searches were limited to peer-reviewed articles published up to October 14, 2021. The included publications aimed at eliciting care preferences for persons with dementia from patients, relatives, healthcare practitioners or the broader public by means of MCDA.

Results

Ten studies were included of whom seven were published in 2017 or afterwards. In nine studies, a discrete choice experiment (DCE) was conducted. The majority of studies surveyed the general population or caregivers of persons with dementia. Five studies assessed preferences for attributes of home care and two for long-term care facilities. Willingness to pay was addressed in eight studies. Choice task structure and experimental design varied widely. Despite different objectives, strong preferences for continuous care by the same person, organizational aspects, and caregiver expertise were found across studies.

Conclusion

This review shows that MCDA methods have successfully been applied to analyze preferences for living and care arrangements for persons with dementia. The majority of publications report on DCEs, and a variety of different study objectives and methodological approaches have been observed. Further research is needed to inform the design of innovative concepts which are a valuable alternative to existing care options.

Parental preference for influenza vaccine for children in China: a discrete choice experiment

OBJECTIVES

To investigate what factors affect parents' influenza vaccination preference for their children and whether there exists preference heterogeneity among respondents in China.

DESIGN

Cross-sectional study. A discrete choice experiment was conducted. Five attributes were identified based on literature review and qualitative interviews, including protection rate, duration of vaccine-induced protection, risk of serious side effects, location of manufacturer and out-of-pocket cost.

SETTING

Multistage sampling design was used. According to geographical location and the level of economic development, 10 provinces in China were selected, and the survey was conducted at community healthcare centres or stations.

PARTICIPANTS

Parents with at least one child aged between 6 months and 5 years old were recruited and the survey was conducted via a face-to-face interview in 2019. In total, 600 parents completed the survey, and 449 who passed the internal consistency test were included in the main analysis.

MAIN OUTCOMES AND MEASURES

A mixed logit model was used to estimate factors affecting parents' preference to vaccinate their children. In addition, sociodemographic characteristics were included to explore the preference heterogeneity.

RESULTS

In general, respondents preferred to vaccinate their children. All attributes were statistically significant and among them, the risk of severe side effects was the most important attribute, followed by the protection rate and duration of vaccine-induced protection. Contrary to our initial expectation, respondents have a stronger preference for the domestic than the imported vaccine. Some preference heterogeneity among parents was also found and in particular, parents who were older, or highly educated placed a higher weight on a higher protection rate.

CONCLUSION

Vaccination safety and vaccine effectiveness are the two most important characteristics that influenced parents' decision to vaccinate against influenza for their children in China. Results from this study will facilitate future policy implementations to improve vaccination uptake rates.

Social preferences for adopting new vaccines in the national immunization program: A discrete choice experiment

Governments regularly have to decide whether new vaccines should be adopted in their national immunization program. These choices imply complex trade-offs of epidemiological, medical and socio-economic criteria. We investigated how the population in Flanders (Belgium) wants their government to set vaccine-funding priorities. In December 2019, we executed a discrete choice experiment in a sample of the Flemish population (N = 1636). In total, we analysed 16 360 choices between vaccines competing for funding, described in terms of eight characteristics. Using a panel mixed logit model, we quantified the relative importance of each characteristic and investigated differences in preferences across respondent groups. The observed vaccine priorities were different from those that would be identified through cost-effectiveness analysis. People valued the health impact from infectious diseases differently than their weight expressed in QALYs would suggest. Mortality and frequently occurring mild illness were valued higher, whereas lasting morbidity received lower weight. Contribution of the vaccine to disease eradication and uncertainty in vaccine effectiveness were both highly influential factors. Health equity impact was also important whereas the economic impact of the disease did not matter at all. Our results can be used to incorporate public values into vaccine decision-making.

Parental Preferences of Influenza Vaccination for Children in China: A National Survey with a Discrete Choice Experiment

The influenza vaccination coverage among children is low in China. We aimed to conduct a nationwide survey to quantify parental preferences and willingness to pay (WTP) for influenza vaccination for their children. Parents with children aged six months to 18 years from six provinces in China were investigated by a discrete choice experiment regarding six influenza vaccination attributes. Mixed logit models were used to estimate the relative importance of vaccine attributes and parents’ WTP. Interaction analysis and subgroup analysis were conducted to explore preference heterogeneity. A total of 1206 parents were included in the analysis. Parents reported vaccine effectiveness as the most important vaccine attribute. The mode of vaccine administration had no significant impact on parents’ preferences. Parents aged over 30 years with higher education or income levels were more likely to prefer no influenza vaccination for their children. The largest marginal WTP (CNY 802.57) for vaccination and the largest increase in vaccine uptake (41.85%) occurred with improved vaccine effectiveness from 30% to 80%. Parents from central regions or mid-latitude areas had a relatively lower WTP than those from other regions. No significant difference in the relative importance of vaccine attributes were observed among parents from various regions of China.

Immediate and informative feedback during a pandemic: Using stated preference analysis to predict vaccine uptake rates

In response to an emerging pandemic, there is urgent need for information regarding individual evaluation of risk and preferences toward mitigation strategies such as vaccinations. However, with social distancing policies and financial stress during an outbreak, traditional robust survey methodologies of face-to-face, probabilistic sampling, may not be feasible to deploy quickly, especially in developing countries. We recommend a protocol that calls for a sensitive survey design, acceptance of a web-based approach and adjustments for uncertainty of respondents, to deliver urgently needed information to policymakers as the public health crisis unfolds, rather than in its aftermath. This information is critical to tailor comprehensive vaccination campaigns that reach critical immunity thresholds. We apply our recommendations in a regional study of 16 Latin American countries in the month following index cases of COVID-19. We use a split-sample, contingent valuation approach to evaluate the effects of cost, duration of immunity and effectiveness of the vaccine. Our results show that cost and duration of immunity are significant factors in the decision to vaccinate, while the degree of effectiveness is insignificant, unless the vaccine is 100% effective. Income as well as perceived risk and severity of the virus are important determinants also.

Vaccine preferences driving vaccine-decision making of different target groups: a systematic review of choice-based experiments

BACKGROUND

Choice-based experiments have been increasingly used to elicit preferences for vaccines and vaccination programs. This study aims to systematically identify and examine choice-based experiments assessing (differences in) vaccine preferences of vaccinees, representatives and health advisors.

METHODS

Five electronic databases were searched on choice-based conjoint analysis studies or discrete choice experiments capturing vaccine preferences of children, adolescents, parents, adults and healthcare professionals for attributes of vaccines or vaccine settings up to September 2020. Data was extracted using a standardized form covering all important aspects of choice experiments. A quality assessment was used to assess the validity of studies. Attributes were categorized into outcome, process, cost and other. The importance of attributes was assessed by the frequency of reporting and statistical significance. Results were compared between high-quality studies and lower-quality studies.

RESULTS

A total of 42 studies were included, with the majority conducted in high-income countries after 2010 (resp. n = 34 and n = 37). Preferences of representatives were studied in nearly half of the studies (47.6%), followed by vaccinees (35.7%) and health advisors (9.5%). Sixteen high-quality studies passed the quality assessment. Outcome- and cost- related attributes such as vaccine effectiveness, vaccine risk, cost and protection duration were most often statistically significant across both target groups, with vaccine effectiveness being the most important. Risks associated with vaccination, such as side effects, were more often statistically significant in studies targeting vaccinees, while cost-related attributes were more often statistically significant in studies of representatives. Process-related attributes such as vaccine accessibility and time were least important across both target groups.

CONCLUSION

To our knowledge, this is the first systematic review in which vaccine preferences of different target groups were assessed and compared. The same attributes were most important for vaccine decisions of vaccinees and representatives, with only minor differences in level of evidence for vaccine risk and cost. Future research on vaccine preferences of health advisors and/or among target groups in low-resource settings would give insight into the generalizability of current findings.

Methods for Conducting Stated Preference Research with Children and Adolescents in Health: A Scoping Review of the Application of Discrete Choice Experiments

BACKGROUND

Discrete choice experiments (DCEs) are a common method used to describe and quantitatively assess preferences in health applications. Increasingly, DCEs have been used to elicit preferences from children and adolescents and generate evidence to inform policies affecting this population.

OBJECTIVES

The aim of this review was to summarize and describe the application of DCEs conducted with children and adolescents and describe author-reported age-specific considerations in design, implementation, and analysis.

METHODS

A scoping review was conducted using a 'pearl-growing' technique whereby the reference lists of existing systematic reviews of DCEs were used to identify potential studies conducted with children or adolescents as respondents published between 1990 and 2017. This list was supplemented with an updated electronic search using the same strategy as the initial reviews to identify studies from 2017 to 2020.

RESULTS

Of 480 studies identified, 19 were included; topics included vaccines (32%), drugs/medical devices (26%), treatment or health promotion interventions/programs (21%), warning labels on cigarettes/nicotine products (10%), and preferences for physical activity and healthy food choices (10%). The youngest reported age for independent DCE completion was 8 years. Approaches to assessing validity and reliability of choices were consistent with best practices for the conduct of DCEs. Reported age-specific considerations included use of visual aids, age-appropriate language, reducing task complexity and cognitive burden, and exploration of interpretation of willingness-to-pay.

CONCLUSION

The number of DCEs conducted with children and adolescents has increased in recent years. Detailed explanation of why reported age-specific considerations were necessary, how they could be used to interpret results, or to understand the appropriateness of this methodology for different age groups was limited. Despite a recognition of the need for special consideration when conducting DCEs in this population, the unique issues in the context of age-specific considerations are largely unexplored, and further research is required. Moving forward, stated preference research conducted with children and adolescents should report in more detail methods of recruitment, results of validity assessments, and provide specific reflection on the extent to which modeled results are consistent with expectations and underlying theory.

Individual preferences for COVID-19 vaccination in China

BACKGROUND

Vaccinations are an effective choice to stop disease outbreaks, including COVID-19. There is little research on individuals' COVID-19 vaccination decision-making.

OBJECTIVE

We aimed to determine individual preferences for COVID-19 vaccinations in China, and to assess the factors influencing vaccination decision-making to facilitate vaccination coverage.

METHODS

A D-efficient discrete choice experiment was conducted across six Chinese provinces selected by the stratified random sampling method. Vaccine choice sets were constructed using seven attributes: vaccine effectiveness, side-effects, accessibility, number of doses, vaccination sites, duration of vaccine protection, and proportion of acquaintances vaccinated. Conditional logit and latent class models were used to identify preferences.

RESULTS

Although all seven attributes were proved to significantly influence respondents' vaccination decision, vaccine effectiveness, side-effects and proportion of acquaintances vaccinated were the most important. We also found a higher probability of vaccinating when the vaccine was more effective; risks of serious side effects were small; vaccinations were free and voluntary; the fewer the number of doses; the longer the protection duration; and the higher the proportion of acquaintances vaccinated. Higher local vaccine coverage created altruistic herd incentives to vaccinate rather than free-rider problems. The predicted vaccination uptake of the optimal vaccination scenario in our study was 84.77%. Preference heterogeneity was substantial. Individuals who were older, had a lower education level, lower income, higher trust in the vaccine and higher perceived risk of infection, displayed a higher probability to vaccinate.

CONCLUSIONS

Preference heterogeneity among individuals should lead health authorities to address the diversity of expectations about COVID-19 vaccinations. To maximize COVID-19 vaccine uptake, health authorities should promote vaccine effectiveness; pro-actively communicate the absence or presence of vaccine side effects; and ensure rapid and wide media communication about local vaccine coverage.

Parental Vaccine Preferences for Their Children in China: A Discrete Choice Experiment

Vaccination is one of the most cost-effective health investments to prevent and control communicable diseases. Improving the vaccination rate of children is important for all nations, and for China in particular since the advent of the two-child policy. This study aims to elicit the stated preference of parents for vaccination following recent vaccine-related incidents in China. Potential preference heterogeneity was also explored among respondents. Methods: A discrete choice experiment was developed to elicit parental preferences regarding the key features of vaccines in 2019. The study recruited a national sample of parents from 10 provinces who had at least one child aged between 6 months and 5 years old. A conditional logit model and a mixed logit model were used to estimate parental preference. Results: A total of 598 parents completed the questionnaire; among them, 428 respondents who passed the rational tests were analyzed. All attributes except for the severity of diseases prevented by vaccines were statistically significant. The risk of severe side effects and protection rates were the two most important factors explaining parents’ decisions about vaccination. The results of the mixed logit model with interactions indicate that fathers or rural parents were more likely to vaccinate their children, and children whose health was not good were also more likely to be vaccinated. In addition, parents who were not more than 30 years old had a stronger preference for efficiency, and well-educated parents preferred imported vaccines with the lowest risk of severe side effects. Conclusion: When deciding about vaccinations for their children, parents in China are mostly driven by vaccination safety and vaccine effectiveness and were not affected by the severity of diseases. These findings will be useful for increasing the acceptability of vaccination in China.

Attributes influencing parental decision-making to receive the Tdap vaccine to reduce the risk of pertussis transmission to their newborn - outcome of a cross-sectional conjoint experiment in Spain and Italy

Pertussis vaccination of parents and household contacts (‘cocooning’) to protect newborn infants is an established strategy in many countries, although uptake may be low. Many aspects may influence such decision-making. We conducted a cross-sectional survey (NCT01890447) of households and other close contacts of newborns aged ≤6 months (or of expectant mothers in their last trimester) in Spain and Italy, using an adaptive discrete-choice experiment questionnaire. Aims were to assess the relative importance of attributes influencing vaccine adoption, and to estimate variation in vaccine adoption rates and the impact of cost on vaccination rates. Six hundred and fifteen participants (Spain, n = 313; Italy, n = 302) completed the survey. Of 144 available questionnaire scenarios, the most frequently selected (14% of respondents in both countries) were infant protection by household vaccination at vaccination center, recommendation by family physician and health authorities, with information available on leaflets and websites. The attribute with highest median relative importance was ‘reduction in source of infection’ in Spain (23.1%) and ‘vaccination location’ in Italy (18.8%). Differences between other attributes were low in both countries, with media attributes showing low importance. Over 80% of respondents indicated a definite or probable response to vaccine adoption (at no-cost) with estimated probability of adoption of 89–98%; applying vaccine costs (25€ per person) would reduce the probability of uptake by 7–20% in definite/probable respondents. Awareness of these determinants is helpful in informing Health Authorities and healthcare practitioners implementing a cocooning strategy for those populations where maternal immunization is not a preferred option.

Discrete Choice Experiments in Health Economics: Past, Present and Future

OBJECTIVES

Discrete choice experiments (DCEs) are increasingly advocated as a way to quantify preferences for health. However, increasing support does not necessarily result in increasing quality. Although specific reviews have been conducted in certain contexts, there exists no recent description of the general state of the science of health-related DCEs. The aim of this paper was to update prior reviews (1990-2012), to identify all health-related DCEs and to provide a description of trends, current practice and future challenges.

METHODS

A systematic literature review was conducted to identify health-related empirical DCEs published between 2013 and 2017. The search strategy and data extraction replicated prior reviews to allow the reporting of trends, although additional extraction fields were incorporated.

RESULTS

Of the 7877 abstracts generated, 301 studies met the inclusion criteria and underwent data extraction. In general, the total number of DCEs per year continued to increase, with broader areas of application and increased geographic scope. Studies reported using more sophisticated designs (e.g. D-efficient) with associated software (e.g. Ngene). The trend towards using more sophisticated econometric models also continued. However, many studies presented sophisticated methods with insufficient detail. Qualitative research methods continued to be a popular approach for identifying attributes and levels.

CONCLUSIONS

The use of empirical DCEs in health economics continues to grow. However, inadequate reporting of methodological details inhibits quality assessment. This may reduce decision-makers' confidence in results and their ability to act on the findings. How and when to integrate health-related DCE outcomes into decision-making remains an important area for future research.

The views of the general public on prioritising vaccination programmes against childhood diseases: A qualitative study

BACKGROUND

Decisions regarding which vaccines are funded in the United Kingdom (UK) are increasingly informed by cost-effectiveness analyses. Such analyses use Quality Adjusted Life Years (QALYs) as a measure of effectiveness and assume that QALYs are equal regardless of where and in whom they occur in the population. However, there is increasing debate about whether this QALY approach is appropriate and whether societal preferences for childhood vaccinations should be used to help inform childhood immunisation policy.

OBJECTIVE

To gauge the general public's preferences for prioritising certain characteristics of childhood vaccination, to help inform future policy making decisions in the UK.

DESIGN

Qualitative design using individual face-to-face interviews, with data analysed using an inductive thematic framework approach.

SETTING

Two counties in England, UK.

POPULATION

Adult members of the general public were recruited using the Bristol and South Gloucestershire open electoral registers, using gender and deprivation quotas for each area.

PARTICIPANTS

21 members of the public participated in qualitative interviews.

RESULTS

The qualitative research identified three major themes and several key attributes that influences participant's opinions about priority setting for childhood vaccinations: (1) population segment (i.e. age group, carer impact and social group), (2) vaccine preventable diseases preferences (i.e. disease severity, disease incidence and declining infection) and (3) risks and benefits associated with childhood vaccinations (i.e. vaccine associated side-effects, herd protection and peace of mind).

CONCLUSION

Evidence from this qualitative study suggests that some members of the UK general public have more nuanced views than the health-maximisation approach when considering how childhood vaccines should be prioritised. This is not necessarily captured by the current economic approaches for assessing the benefits from childhood vaccinations in the UK, but is an important area for future research to ensure appropriate decision making.

Physician-Specific Maximum Acceptable Risk in Personalized Medicine: Implications for Medical Decision Making

BACKGROUND

In discrete-choice experiments (DCEs), respondents are presented with a series of scenarios and asked to select their preferred choice. In clinical decision making, DCEs allow one to calculate the maximum acceptable risk (MAR) that a respondent is willing to accept for a one-unit increase in treatment efficacy. Most published studies report the average MAR for the whole sample, without conveying any information about heterogeneity. For a sample of psychiatrists prescribing drugs for a series of hypothetical patients with schizophrenia, this article demonstrates how heterogeneity accounted for in the DCE modeling can be incorporated in the derivation of the MAR.

METHODS

Psychiatrists were given information about a group of patients' responses to treatment on the Positive and Negative Syndrome Scale (PANSS) and the weight gain associated with the treatment observed in a series of 26 vignettes. We estimated a random parameters logit (RPL) model with treatment choice as the dependent variable.

RESULTS

Results from the RPL were used to compute the MAR for the overall sample. This was found to be equal to 4%, implying that, overall, psychiatrists were willing to accept a 4% increase in the risk of an adverse event to obtain a one-unit improvement of symptoms - measured on the PANSS. Heterogeneity was then incorporated in the MAR calculation, finding that MARs ranged between 0.5 and 9.5 across the sample of psychiatrists.

LIMITATIONS

We provided psychiatrists with hypothetical scenarios, and their MAR may change when making decisions for actual patients.

CONCLUSIONS

This analysis aimed to show how it is possible to calculate physician-specific MARs and to discuss how MAR heterogeneity could have implications for medical practice.