Adolescent Girls’ Preferences for HPV Vaccines: A Discrete Choice Experiment

Willingness to pay for cancer prevention, screening, diagnosis, and treatment: a systematic review

INTRODUCTION

Willingness to pay (WTP) studies examine the maximum amount of money an individual is willing to pay for a specified health intervention, and can be used to inform coverage and reimbursement decisions. Our objectives were to assess how people value cancer-related interventions, identify differences in the methodologies used, and review the trends in studies' publication.

AREAS COVERED

We extracted PubMed and EconLit articles published in 1997-2020 that reported WTP for cancer-related interventions, characterized the methodological differences and summarized each intervention's mean and median WTP values. We reviewed 1,331 abstracts and identified 103 relevant WTP studies, of which 37 (36%) focused on treatment followed by screening (26), prevention (21), diagnosis (7) and other interventions (12). The methods used to determine WTP values were primarily discrete-choice questions (n = 54, 52%), bidding games (15), payment cards (12) and open-ended questions (12). We found a wide variation in WTP reported values ranged from below $100 to over $20,000.

EXPERT OPINION

The WTP literature on oncology interventions has grown rapidly. There is considerable heterogeneity with respect to the type of interventions and diseases assessed, the respondents' characteristics, and the study methodologies. This points to the need to establish international guidelines for best practices in this field.

Current Practices for Accounting for Preference Heterogeneity in Health-Related Discrete Choice Experiments: A Systematic Review

BACKGROUND

Accounting for preference heterogeneity is a growing analytical practice in health-related discrete choice experiments (DCEs). As heterogeneity may be examined from different stakeholder perspectives with different methods, identifying the breadth of these methodological approaches and understanding the differences are major steps to provide guidance on good research practices.

OBJECTIVES

Our objective was to systematically summarize current practices that account for preference heterogeneity based on the published DCEs related to healthcare.

METHODS

This systematic review is part of the project led by the Professional Society for Health Economics and Outcomes Research (ISPOR) health preference research special interest group. The systematic review conducted systematic searches on the PubMed, OVID, and Web of Science databases, as well as on two recently published reviews, to identify articles. The review included health-related DCE articles published between 1 January 2000 and 30 March 2020. All the included articles also presented evidence on preference heterogeneity analysis based on either explained or unexplained factors or both.

RESULTS

Overall, 342 of the 2202 (16%) articles met the inclusion/exclusion criteria for extraction. The trend showed that analyses of preference heterogeneity increased substantially after 2010 and that such analyses mainly examined heterogeneity due to observable or unobservable factors in individual characteristics. Heterogeneity through observable differences (i.e., explained heterogeneity) is identified among 131 (40%) of the 342 articles and included one or more interactions between an attribute variable and an observable characteristic of the respondent. To capture unobserved heterogeneity (i.e., unexplained heterogeneity), the studies largely estimated either a mixed logit (n = 205, 60%) or a latent-class logit (n = 112, 32.7%) model. Few studies (n = 38, 11%) explored scale heterogeneity or heteroskedasticity.

CONCLUSIONS

Providing preference heterogeneity evidence in health-related DCEs has been found as an increasingly used practice among researchers. In recent studies, controlling for unexplained preference heterogeneity has been seen as a common practice rather than explained ones (e.g., interactions), yet a lack of providing methodological details has been observed in many studies that might impact the quality of analysis. As heterogeneity can be assessed from different stakeholder perspectives with different methods, researchers should become more technically pronounced to increase confidence in the results and improve the ability of decision makers to act on the preference evidence.

The application of discrete choice experiments eliciting young peoples' preferences for healthcare: a systematic literature review

OBJECTIVES

Understanding young people's preferences for healthcare is critical for reducing the negative effect of undesirable choices. This review aims to synthesise the evidence obtained from discrete choice experiments (DCEs) eliciting young people's preferences for healthcare interventions and service deliveries, specifically, to (1) examine the methodology, including a selection of attributes and levels, experimental design, estimation procedure and validity; (2) evaluate similarities, differences and rigour of designs to the general population DCEs; and, (3) compare the DCEs' application to the seven health priority areas defined by the World Health Organisation (WHO).

METHODS

A systematic review searching Medline, EconLIT, PsychINFO, Scopus, and Web of Science was performed up until May 2021.

INCLUSION CRITERIA

a DCE, eliciting young peoples' preferences (10-24 years of age), on a healthcare-related topic defined by WHO, peer-reviewed, full-text available in English. A bespoke checklist was used to assess the methodological quality of the included studies.

RESULTS

Eighteen DCE studies were included in the review, exploring interventions and service in sexual and reproductive health (n = 9; 50%), smoking cessation (n = 4; 22%), mental health (n = 1), nutrition (n = 1), unintentional injuries (n = 1), vaccination against severe but rare diseases (n = 1); and diabetes (n = 1). Compared to the general population, DCEs eliciting young people's preferences had a high proportion of monetary measures and a smaller number of choices per respondent with the overwhelming number of surveys using fractional factorial design. The majority of studies were of moderate quality (50-75% of the criteria met).

CONCLUSIONS

While identified DCEs touched on most health priority areas, the scope was limited. The conduct and reporting of DCEs with young people could be improved by including the state-of-the-art design, estimation procedures and analysis.

The Value(s) of Vaccination: Building the Scientific Evidence According to a Value-Based Healthcare Approach

Objectives

To provide a new value-based immunization approach collating the available scientific evidence on the topic.

Methods

Four value pillars (personal, allocative, technical, and societal) applied to vaccination field were investigated. A systematic literature review was performed querying three database from December 24th, 2010 to May 27th, 2020. It included studies on vaccine-preventable diseases (VPDs) that mentioned the term value in any part and which were conducted in advanced economies. An in-depth analysis was performed on studies addressing value as key element.

Results

Overall, 107 studies were considered. Approximately half of the studies addressed value as a key element but in most of cases (83.3%) only a single pillar was assessed. Furthermore, the majority of papers addressed the technical value by looking only at classical methods for economic assessment of vaccinations whereas very few dealt with societal and allocative pillars.

Conclusions

Estimating the vaccinations value is very complex, even though their usefulness is certain. The assessment of the whole value of vaccines and vaccinations is still limited to some domains and should encompass the wider impact on economic growth and societies.

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.

Mothers' preferences and willingness-to-pay for human papillomavirus vaccines in Iran: A discrete choice experiment study

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The relative importance for serious side effects was the highest among all attributes.

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Mothers express more WTP for the quadrivalent vaccine compared to bivalent due to its protection against genital warts.

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Quadrivalent vaccination could be the most suitable candidate for implementation in the national immunization schedule.

This study aimed to identify mothers’ preferences and willingness-to-pay (WTP) for human papillomavirus (HPV) vaccines (in this case, bivalent and quadrivalent) in Iran. We used a discrete choice experiment (DCE) method to present mothers with choices between two hypothetical profiles of vaccines, described by combinations of five attributes, each with two or three levels. We analyzed the DCE results using conditional logistic regression and measured WTP estimates for each attribute. Our response rate was 53.96%, while the completion rate for questioner was 93.57%. We identified protection against cervical cancer, protection against genital warts, protection duration, serious side effects, and cost to influence mothers’ preferences for HPV vaccination. The relative importance for serious side effects was the highest among all attributes. Mothers’ WTP for bivalent and quadrivalent HPV vaccines was in US $ −432 (US $1 = IRR 42,000) and US $ 380, respectively. Quadrivalent vaccination could be the most suitable candidate for implementing the national immunization schedule. The reason is that mothers express more WTP for the quadrivalent vaccine than bivalent due to its protection against genital warts.

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.

Parent, provider and vaccinee preferences for HPV vaccination: A systematic review of discrete choice experiments

OBJECTIVES

To systematically review, appraise and evaluate available evidence regarding discrete-choice experiments (DCEs) for the human papilloma virus (HPV) vaccination in order to support policymakers in making reasonable and effective vaccination program implementation decisions.

METHODS

A systematic literature review was conducted using the databases PubMed and Embase for DCEs in HPV up to May 2019. Extracted data was tabulated and two checklists were used for the quality appraisal of the included studies. All attributes were categorized in outcome, process or costs attributes and the relative importance of attributes was calculated using the range method.

RESULTS

Out of 164 identified studies, 12 met the inclusion criteria. Eight were from high income countries (HICs) and four from low and middle-income countries (LMICs). Five studies each examined vaccinee and parent preferences, while only two assessed the providers' preferences. The studies were rather heterogenous in terms of the populations investigated, the attributes included and the methodologic approach. Overall, outcome measures were the most prominent attributes and effectiveness consistently yielded high relative importance scores. But also process factors, such as the age at vaccination, played an important role for decision making. Discrepancies between HICs and LMICs were most prominent for cost attributes.

CONCLUSION

The heterogenous preferences this review elicited highlight the importance of context when making decisions grounded on consumer preferences. Especially the lack of evidence from LMICs, where the burden of cervical cancer is highest, is worrisome. In order to increase uptake, close vaccination gaps and reduce current inequities in (reproductive) healthcare, policy makers need to understand the features that drive individual vaccination decisions and adapt national and clinical guidelines accordingly. Future research therefore needs to focus on LMICs in order to elicit preferences of those most vulnerable populations.

Acceptance of and preference for COVID-19 vaccination in healthcare workers: a comparative analysis and discrete choice experiment.. [PMID: 0 DOI: 10.1101/2020.04.09.20060103]

Background

A major obstacle to successful coronavirus disease (COVID-19) vaccine rollout is vaccine hesitancy. Acceptance of and preferences for COVID-19 vaccination among healthcare workers (HCWs) is critical, because they are a key target group for vaccination programs, and they are also highly influential to vaccine uptake in the wider population. This study sought to comparatively determine the acceptance of and preference for COVID-19 vaccination among HCWs and the general population.

Methods

An Internet-based, region-stratified discrete-choice experiment was conducted among 352 HCWs and 189 general population respondents recruited in March 2020 from 26 Chinese provinces. We accessed knowledge of disease, attitude towards and acceptance of COVID-19 vaccination. Several attributes (related to COVID-19 disease, COVID-19 vaccination and one social acceptance) were identified as key determinants of vaccine acceptance.

Results

HCWs had a more in-depth understanding of COVID-19 and showed a higher willingness to accept COVID-19 vaccines with lower effectiveness and/or more severe adverse effects compared to the general population. 76.4% of HCWs (vs 72.5% of the general population) expressed willingness to receive vaccination (χ2=2.904, p=0.234). High levels of willingness to accept influenza (65.3%) and pneumococcal (55.7%) vaccination were also seen in HCWs. Future COVID-19 disease incidence (OR: 4.367, 95% CI 3.721–5.126), decisions about vaccination among social contacts of respondents (OR 0.398, 95% CI 0.339–0.467), and infection risk >30% (OR 2.706, 95% CI 1.776–2.425) significantly increased the probability of vaccination acceptance in HCWs.

Conclusion

Multi-component interventions to address the key determinants of hesitancy in both HCWs and in the general population should be considered for COVID-19 vaccination programs.

Use of a choice survey to identify adult, adolescent and parent preferences for vaccination in the United States

Background

Adult and adolescent vaccination rates are far below coverage targets in the United States. Our objective was to identify the most influential factors related to vaccine uptake among adults, adolescents, and parents of adolescents (parents) in the United States.

Methods

We used a fractional factorial design to create a binary choice survey to evaluate preferences for vaccination. The national survey was fielded to a sample of adults, adolescents ages 13–17 years, and parents, using a national probability-based online research panel in November 2015. Respondents were presented with 5 profiles of a hypothetical vaccine and asked in a series of questions whether they would accept each vaccine. We analyzed the binary choice data using logistic regression in STATA v13 (College Station, TX) to calculate the odds that a participant would choose to accept the vaccine.

Results

We received completed responses from 334 (51%) of 652 adults, 316 (21%) of 1516 adolescents, and 339 (33%) of 1030 parents. Respondents were generally representative of the U.S. population. Vaccine effectiveness was the most influential factor in the choice to vaccinate for all groups. Other most influential factors were primary care provider (PCP) recommendation and the out-of-pocket cost of the vaccine. Other factors such as risk of illness, risk of vaccine side effects, vaccination location, and time for vaccination were not important in the decision to get vaccinated.

Conclusions

Adults, adolescents, and parents are most sensitive to vaccine effectiveness, PCP recommendation, and out-of-pocket cost for vaccination in their decision to get vaccinated. Strong PCP recommendations that focus on vaccine effectiveness and health care policies that minimize out-of-pocket costs for vaccinations may increase vaccine uptake by adults and adolescents.

Electronic supplementary material

The online version of this article (10.1186/s41687-019-0135-0) contains supplementary material, which is available to authorized users.

Development of a Discrete-Choice Experiment (DCE) to Elicit Adolescent and Parent Preferences for Hypodontia Treatment

Objective

Our objective was to develop and test a discrete-choice experiment (DCE) survey to elicit adolescent and parent preferences for dental care for hypodontia (a developmental condition where one or more teeth fail to develop).

Methods

This was a mixed-methods study. Participants were adolescents (aged 12–16 years) with hypodontia and their parents and the dentists providing hypodontia care. Stage one entailed attribute development, as follows. (1) Attribute identification: systematic review of hypodontia literature; interviews with adolescents with hypodontia (n = 8) and parents (n = 8); observation of hypodontia clinical consultations (n = 5); environmental scan of hypodontia patient information resources (n = 30); and systematic analysis of social media posts (n = 176). (2) Attribute selection: stakeholder consultation to develop items for a questionnaire; rating and ranking questionnaire for adolescents with hypodontia and parents (n = 18); further stakeholder consultation. Stage two involved the development of the DCE survey, and stage three included the pre-testing using cognitive interviews with adolescents (n = 12) and parents (n = 8) to assess face and content validity.

Results

The attribute long list included 27 attributes focusing on service delivery and treatment outcome, from which seven ‘important’ attributes were selected for pre-testing. Cognitive interviewing suggested adolescents found the DCE choice tasks challenging to understand; the survey was modified to enhance its acceptability. One attribute was excluded as it showed poor validity with adolescents. Pre-testing suggested DCE choice tasks encouraged thinking and discussion about preferences for treatment.

Conclusions

Including the target respondent group in all stages of DCE development ensured the final DCE survey was valid and acceptable. DCE methods appear to be a useful tool for exploring joint decision making alongside conventional preference elicitation.

Electronic supplementary material

The online version of this article (10.1007/s40271-018-0338-0) contains supplementary material, which is available to authorized users.

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.

Colorectal Cancer Screening: Preferences, Past Behavior, and Future Intentions

BACKGROUND

Screening rates for colorectal cancer are below the Healthy People 2020 goal. There are several colorectal cancer screening tests that differ in terms of accuracy, recommended frequency, and administration. In this article, we compare how a set of personal characteristics correlates with preferences for colorectal cancer screening test attributes, past colorectal cancer screening behavior, and future colorectal cancer screening intentions.

METHODS

We conducted a discrete-choice experiment survey to assess relative preferences for attributes of colorectal cancer screening tests among adults aged 50-75 years in USA. We used a latent class logit model to identify classes of preferences and calculated willingness to pay for changes in test attributes. A set of personal characteristics were included in the latent class analysis and analyses of self-reported past screening behavior and self-assessed likelihood of future colorectal cancer screening.

RESULTS

Latent class analysis identified three types of respondents. Class 1 valued test accuracy, class 2 valued removing polyps and avoiding discomfort, and class 3 valued cost. Having had a prior colonoscopy and a higher income were predictors of the likelihood of future screening and membership in classes 1 and 2. Health insurance and a self-reported higher risk of developing colorectal cancer were associated with prior screening and higher future screening intentions, but not class membership.

CONCLUSION

We identified distinct classes of preferences focusing on different test features and personal characteristics associated with reported behavior and intentions. Healthcare providers should engage in a careful assessment of patient preferences when recommending colorectal cancer test options to encourage colorectal cancer screening uptake.

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

BACKGROUND

Discrete choice experiments are increasingly used to assess preferences for vaccines and vaccine service delivery.

OBJECTIVES

To synthesize and critically assess the application of discrete choice experiments in childhood/adolescent vaccines, to describe how discrete choice experiments have been applied to understand preferences, and to evaluate the use of discrete choice experiment data to inform estimates of vaccine uptake.

METHODS

We conducted a systematic review of six electronic databases. Included studies were discrete choice experiments and conjoint analyses published from 2000 to 2016 related to childhood/adolescent vaccines where respondents were parents, children/adolescents, or service providers. Validity assessment was used to assess study quality and risk of bias.

RESULTS

In total, 27 articles were included, representing 21 different studies. A majority of articles were published between 2011 and 2016. Vaccines studied included human papillomavirus (24%), influenza (19%), meningococcal vaccines (14%), childhood vaccines (14%), hypothetical vaccines (10%), hepatitis B (5%), and diphtheria, tetanus, pertussis, hepatitis B, poliomyelitis, and Haemophilus influenzae type b (5%). Most studies assessed parent preferences (67%). The most common attributes were risk (24%), degree/duration of protection (21%), and cost (15%). Commonly reported outcome measures were estimates of uptake (33%), willingness-to-pay (22%), and other marginal rates of substitution (14%). Validity assessments yielded high scores overall. Areas of weakness included low response rates, inefficient experimental design, and failure to conduct formative qualitative work and a pilot of the discrete choice experiment.

CONCLUSION

This is the first systematic review of childhood/adolescent vaccine-related discrete choice experiments. In future, special attention should be paid to ensuring that choice context and discrete choice experiment design are compatible to generate reliable estimates of uptake.

Using Latent Class Analysis to Model Preference Heterogeneity in Health: A Systematic Review

BACKGROUND

Latent class analysis (LCA) has been increasingly used to explore preference heterogeneity, but the literature has not been systematically explored and hence best practices are not understood.

OBJECTIVE

We sought to document all applications of LCA in the stated-preference literature in health and to inform future studies by identifying current norms in published applications.

METHODS

We conducted a systematic review of the MEDLINE, EMBASE, EconLit, Web of Science, and PsycINFO databases. We included stated-preference studies that used LCA to explore preference heterogeneity in healthcare or public health. Two co-authors independently evaluated titles, abstracts, and full-text articles. Abstracted key outcomes included segmentation methods, preference elicitation methods, number of attributes and levels, sample size, model selection criteria, number of classes reported, and hypotheses tests. Study data quality and validity were assessed with the Purpose, Respondents, Explanation, Findings, and Significance (PREFS) quality checklist.

RESULTS

We identified 2560 titles, 99 of which met the inclusion criteria for the review. Two-thirds of the studies focused on the preferences of patients and the general population. In total, 80% of the studies used discrete choice experiments. Studies used between three and 20 attributes, most commonly four to six. Sample size in LCAs ranged from 47 to 2068, with one-third between 100 and 300. Over 90% of the studies used latent class logit models for segmentation. Bayesian information criterion (BIC), Akaike information criterion (AIC), and log-likelihood (LL) were commonly used for model selection, and class size and interpretability were also considered in some studies. About 80% of studies reported two to three classes. The number of classes reported was not correlated with any study characteristics or study population characteristics (p > 0.05). Only 30% of the studies reported using statistical tests to detect significant variations in preferences between classes. Less than half of the studies reported that individual characteristics were included in the segmentation models, and 30% reported that post-estimation analyses were conducted to examine class characteristics. While a higher percentage of studies discussed clinical implications of the segmentation results, an increasing number of studies proposed policy recommendations based on segmentation results since 2010.

CONCLUSIONS

LCA is increasingly used to study preference heterogeneity in health and support decision-making. However, there is little consensus on best practices as its application in health is relatively new. With an increasing demand to study preference heterogeneity, guidance is needed to improve the quality of applications of segmentation methods in health to support policy development and clinical practice.

German travelers' preferences for travel vaccines assessed by a discrete choice experiment

BACKGROUND

Many travelers to regions with endemic infectious diseases do not follow health authorities' recommendations regarding vaccination against vaccine-preventable infectious diseases, before traveling. The determinants of individual travelers' decisions to vaccinate before traveling are largely unknown. This study aimed to provide this information using a discrete choice experiment (DCE) administered to four types of German travelers: (1) business travelers; (2) travelers visiting friends and relatives (VFR); (3) leisure travelers; and (4) backpackers.

METHODS

A DCE survey was developed, pretested and administered online. It included a series of choice questions in which respondents chose between two hypothetical vaccines, each characterized by four disease attributes with varying levels describing the of risk, health impact, curability and transmissibility of the disease they would prevent (described with four disease attributes with varying levels of risk, health impact, curability and transmissibility), and varying levels of four vaccine attributes (duration of protection, number of doses required, time required for vaccination, and vaccine cost). A random-parameters logit model was used to estimate the importance weights each traveler type placed on the various attribute levels. These weights were used to calculate mean monetary equivalents (MMEs) of changes in each attribute (holding all others constant) and of hypothetical disease-vaccine combinations.

RESULTS

All traveler types' choices indicated that they attached the greatest importance to the risk and health impact of disease and to the vaccine cost whereas the other disease and vaccine attributes were less important for their decisions about travel vaccines. An option of not choosing any of the vaccine-pairs presented was rarely selected indicating that travelers' generally prefer to be vaccinated rather than not. The MMEs of changes in vaccine attributes indicated a very high variability between the individual travelers within each type.

CONCLUSIONS

The travelers' responses indicated strong preferences for selecting vaccination rather than opting out of vaccination, and disease risk, health impact and vaccine cost were the most important features for vaccine choice.

Adolescent values for immunisation programs in Australia: A discrete choice experiment

Objectives

The importance of adolescent engagement in health decisions and public health programs such as immunisation is becoming increasingly recognised. Understanding adolescent preferences and further identifying barriers and facilitators for immunisation acceptance is critical to the success of adolescent immunisation programs. This study applied a discrete choice experiment (DCE) to assess vaccination preferences in adolescents.

Methods

This study was conducted as a cross-sectional, national online survey in Australian adolescents. The DCE survey evaluated adolescent vaccination preferences. Six attributes were assessed including disease severity, target for protection, price, location of vaccination provision, potential side effects and vaccine delivery method. A mixed logit model was used to analyse DCE data.

Results

This survey was conducted between December 2014 and January 2015. Of 800 adolescents aged 15 to 19 years, stronger preferences were observed overall for: vaccination in the case of a life threatening illness (p<0.001), lower price vaccinations (p<0.001), mild but common side effects (p = 0.004), delivery via a skin patch (p<0.001) and being administered by a family practitioner (p<0.001). Participants suggested that they and their families would be willing to pay AU$394.28 (95%CI: AU$348.40 to AU$446.92) more for a vaccine targeting a life threatening illness than a mild-moderate illness, AU$37.94 (95%CI: AU$19.22 to AU$57.39) more for being vaccinated at a family practitioner clinic than a council immunisation clinic, AU$23.01 (95%CI: AU$7.12 to AU$39.24) more for common but mild and resolving side effects compared to rare but serious side effects, and AU$51.80 (95%CI: AU$30.42 to AU$73.70) more for delivery via a skin patch than injection.

Conclusions

Consideration of adolescent preferences may result in improved acceptance of, engagement in and uptake of immunisation programs targeted for this age group.

Variation in Treatment Priorities for Chronic Hepatitis C: A Latent Class Analysis

BACKGROUND

Data describing patients' priorities, or main concerns, are essential to inform important decisions in healthcare, including treatment planning, diagnostic testing, and the development of programs to improve access and delivery of care. To date, the majority of studies performed does not account for variability in patients' priorities, and as a consequence may not effectively inform end users. The objective of this study was to examine the value of segmentation analysis as a method to illustrate variability in priorities for treatment of chronic hepatitis C (HCV).

METHODS

We elicited patients' main concerns when considering antiviral therapy for HCV using a Best-Worst Scaling experiment (Case 1) with ten objects. Latent class analysis was used to estimate part-worth utilities and the probability that each respondent belongs to each segment.

RESULTS

In the aggregate, subjects (N = 162) had three main concerns: (1) not being cured; (2) experiencing a lot of side effects; and (3) developing viral resistance to therapy. Segmentation into two groups demonstrated that both groups prioritized the likelihood of cure and coping with side effects, but that only one group (n = 78) was concerned about developing viral resistance to therapy, while subjects in the second group (n = 84) prioritized being able to keep up with their responsibilities. Further segmentation revealed distinct clusters of patients with unique priorities.

CONCLUSIONS

Patients' priorities vary significantly. Preference studies should consider including methods to determine whether distinct clusters of priorities and/or concerns exist in order to accurately inform end users' decision making.

Who Wants Long-Term Care Insurance? A Stated Preference Survey of Attitudes, Beliefs, and Characteristics

Approximately half of people turning 65 years between 2015 and 2019 are projected to need long-term support and services. Yet the long-term care insurance (LTCI) market is depressed, with only 7.4 million people owning policies. The objective of this study was to provide an analysis of potential LTCI purchasers. We investigate (1) who wants to purchase LTCI, (2) what are the attitudes and beliefs among those who have a preference for LTCI, and (3) who would prefer a law mandating the purchase of LTCI and how that view relates to willingness to purchase LTC. We combine a discrete choice experiment with a survey on attitudes toward LTCI. We estimate odds ratio for choosing a plan based on sociodemographic characteristics, attitudes, and beliefs. Our sample consists of a population of 12 936 people who completed an Internet panel survey. Female respondents were substantially less likely to choose an LTCI plan (OR = 0.74). Income and assets over $100 000 were strong predictors of LTCI uptake (OR = 1.27 and OR = 1.48, respectively). Having adult children live close by was not associated with preference for LTCI. People who support almost any government intervention are more likely to purchase private insurance (OR = 1.12-1.33). Minorities expressed a preference for mandatory enrollment relative to whites. There is a relationship between attitudes toward long-term care financing reform and preference for LTCI, but it is not limited to supporters of private sector initiatives. While support for mandatory LTCI is low overall, it is strongest among racial/ethnic minorities and people with health problems, who potentially have the most to gain.