Parents' preferences and willingness-to-pay for human papilloma virus vaccines in Thailand

Investigating preferences of the covid-19 vaccine among individuals in Iran: Discrete choice experiment analysis

Background and Aims

This study aimed to estimate the preferences for COVID-19 vaccines among a sample of Iranian adults and to understand the sources of preference heterogeneity.

Methods

A web-based survey was conducted from April to July 2021; out of 1747 participants, 678 completed the survey. Seven key attributes were selected, namely effectiveness, risk of severe side effects, risk of mild side effects, number of doses, duration of protection, location of manufacture, and price. Additionally, conditional logit and mixed logit models were used to analyze the data.

Results

The results of this study indicate that vaccine effectiveness, protective duration, the risk of side effects, and price are the most important factors that influence vaccine preferences. Furthermore, we identified heterogeneity in preferences, indicating that not all individuals respond in the same way to vaccine attributes.

Conclusion

The majority of Iranians prefer to get the Covid-19 vaccine. Policymakers should consider these findings when implementing successful programs. This study contributes to the literature by estimating Iranian respondents' preferences for the Covid-19 vaccine and identifying the heterogeneity in their preferences for vaccine attributes. The findings may also inform future research and policies related to Covid-19 vaccination programs in Iran.

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.

Stated preferences for human papillomavirus vaccination for adolescents in selected communities in Ibadan, Southwest Nigeria: A discrete choice experiment

Administration of the human papillomavirus (HPV) vaccine in early adolescence is effective in preventing cervical cancer, a common cancer in sub-Saharan Africa. Nigeria is in the pre-introduction era of the HPV vaccine. Understanding the preferences of the population for the vaccine can help design the HPV immunization program to ensure high uptake of the vaccine. This study explored the preferences for the HPV vaccine among stakeholders in selected communities in Ibadan, Nigeria. A discrete choice experiment survey based on six attributes of the HPV vaccine (which were the number of doses, the efficacy of the vaccine, cost of the vaccine, location of the service point, other benefits of the vaccine apart from prevention of cervical cancer and the odds of a side effect from the vaccine) was carried out in five communities. Data were analyzed using conditional and mixed logit models. Seven hundred community members were recruited, 144 (20.7%) were adolescents and 248 (35.4%) were males. In line with expectations, respondents preferred vaccines with higher efficacy, less severe side effects and lower costs. Preference heterogeneity was identified for adolescents that were less price-sensitive and other community members who were less likely to prefer using schools as the service point. The high socioeconomic class preferred a vaccine that also prevents genital warts. There were variabilities in the preferences for the attributes of the HPV vaccine in the study communities. These variabilities need to be considered in the introduction of the HPV vaccine to ensure high uptake of the vaccine.

Willingness-to-pay for a booster dose of inactivated SARS-CoV-2 vaccine in Taizhou, China

This study was conducted to ascertain whether people in China would be willing to pay for an inactivated COVID-19 vaccine booster dose. An online survey estimating participants' willingness to pay (WTP) for a booster dose of COVID-19 vaccine was conducted in Taizhou, China. The participants received ane-mail or e-poster on WeChat. A total of 1576 subjects participated the survey. A total of 66.4% (1046/1576) of the respondents were willing to pay for a booster dose of COVID-19 vaccine for themselves. Using binary logistic regression analysis, the following factors were significantly related to a WTP for a booster dose of COVID-19 vaccine: 1) confidence in the safety of the COVID-19 vaccines (high vs. low, OR: 4.30, 95%CI: 1.61-11.43), 2) confidence in the preventive effectiveness of the COVID-19 vaccines against SARS-CoV-2 virus (moderate vs. little, OR: 1.76, 95%CI: 1.30-2.38; great vs. little, OR: 2.244, 95%CI: 1.62-3.12), and 3) COVID-19 vaccine hesitancy (unhesitant vs. very unhesitant, OR: 0.67, 95%CI: 0.45-1.02; hesitant vs. very unhesitant, OR: 0.29, 95%CI: 0.19-0.44; very hesitant vs. very unhesitant, OR: 0.09, 95%CI: 0.03-0.27). This study revealed that a moderate proportion of participants responded that they would be willing to pay for a booster dose of COVID-19 vaccine. These findings suggest the importance of a detailed assessment and a health education plan that better understands the population's risk perception as well as the potential health risks in China.

Parental intention to vaccinate adolescents with HPV vaccine in selected communities in Ibadan, Southwest Nigeria: an application of Integrated Behavioral Model

Parents have important roles to play for adolescents to get the human papillomavirus (HPV) vaccine, an effective measure in the prevention of cervical and other HPV-related cancers. It is important to understand the intention of parents to have their adolescents vaccinated for optimal uptake of the vaccine in Nigeria. This study investigated the intention of parents in five selected communities to get their adolescents vaccinated with HPV vaccine in Ibadan, Nigeria using the Integrated Behavioral Model (IBM). Cross sectional study design was employed and 678 parents were interviewed. Pearson correlation, chi-square test and multiple regression were used for data analysis at α = 0.05. Mean age of the parents was 42.5 ± 10.0 years and 230(33.9%) were males. Almost all of the parents (96.8%) had the intention to vaccinate their adolescents with HPV vaccine. This intention was significantly correlated with experiential attitude (r = 0.74, p = <.01), instrumental attitude (r = 0.33, p = <.01), injunctive norm (r = 0.39, p = <.01), descriptive norm (r = 0.32, p = <.01), perceived control (r = 0.32, p = <.01) and self-efficacy (r = 0.46, p ≤ .01). A higher proportion of parents older than 65 years significantly had no intention to vaccinate their adolescents with HPV vaccine. Intention to vaccinate adolescents with HPV vaccine was predicted by experiential attitude (OR = 0.88, 95% CI: 0.80-0.95), personal agency (OR = 0.22, 95% CI: 0.15-0.29) and injunctive norm (OR = 0.08, 95% CI: 0.02-0.13). Parental intention to vaccinate adolescents with HPV vaccine was high among the parents in this study. The reluctance of older parents about HPV vaccine for adolescents requires further investigation.

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.

Willingness and influential factors of parents of 3-6-year-old children to vaccinate their children with the COVID-19 vaccine in China

The impact of Coronavirus disease 2019 (COVID-19) on children aged 3-6 can be severe. Vaccination for COVID-19 is one of the most important primary preventative measures to reduce disease transmission. Parents are hesitant to vaccinate their children against COVID-19 because it was reported in the news that some adults have had adverse reactions to the vaccine. This study aims to investigate the willingness of Chinese parents of 3-6 year old children to vaccinate them with the COVID-19 vaccine and identify what factors influence their decisions. A survey was conducted using a two-stage stratified random sampling method from December 2020 to February 2021. We used univariate analysis and multivariate binary logistic analysis to explore potential factors that may determine the acceptance of the COVID-19 vaccine. Of the 468 parents who participated, 86.75% were willing to vaccinate their children with the COVID-19 vaccine. Parents who were female (OR = 2.591; 95% CI: 0.432-4.689), recognized their children in the high-risk category (OR = 2.494; 95% CI:1.244-5.002), often followed-up with COVID-19 vaccine-related information (OR = 9.065; 95% CI: 3.220-28.654), believed in the safety of the COVID-19 vaccine (OR = 3.068; 95% CI: 1.313-7.168), or thought the COVID-19 vaccine could prevent COVID-19 (OR = 13.750; 95% CI: 2.516-75.140) were more willing to vaccinate their children. To ease parents' hesitation about vaccines, the authority organization should release updated information on the safety and reliability of vaccines, target gender-specific health education for parents, and ask the media to report scientifically support information.

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.

Preference of influenza vaccination among the elderly population in Shaanxi province, China

The influenza vaccination uptake rate is low in China. In the current study, we aimed to explore the preferences of influenza vaccination among the Chinese elderly. A discrete choice experiment design was performed to assess their preferences toward five influenza vaccination attributes, including vaccine effectiveness, duration of protection, severe adverse effects, vaccination cost, and vaccination recommendation source. A total of 144 participants aged over 60 years from three cities of Shaanxi province in China were surveyed. A mixed logit model was employed to analyze the data. The elderly population were found to prefer influenza vaccination with a longer duration of protection, followed by lower severe adverse effects, higher vaccine effectiveness, and recommended by healthcare providers. The vaccination cost was the least important attribute. The most considerable marginal willingness to pay for vaccination (CNY220.90) and the highest vaccination choice probability (83.70%) occurred when the duration of protection extended from 3 to 12 months. The present study's findings would inform decision-makers on implementing appropriate interventions for the increase of influenza vaccination coverage among the elderly in China.

The epidemiologic and economic impact of a quadrivalent human papillomavirus vaccine in Thailand

BACKGROUND

The human papillomavirus (HPV) vaccine was introduced into Thailand's national immunization program in 2017 for 11-12 year old school girls. The objectives of this study were to examine the epidemiological consequences and cost-effectiveness of a routine quadrivalent HPV (4vHPV) vaccination and the routine 4vHPV vaccination plus 5-year catch-up vaccination by comparing with cervical cancer screening only (no vaccination) in Thailand.

METHOD

A transmission dynamic model was used to assess the cost-effectiveness of the routine 4vHPV vaccination and the routine 4vHPV vaccination plus catch-up vaccination, compared with no vaccination (screening only) in Thai population. The vaccination coverage rate assumptions were 95% in 11-12-year-old girls for the routine vaccination and 70% in 13-24 year-old females for the 5-year catch-up vaccination. Vaccination costs, direct medical costs of HPV-related diseases, and the number of quality of life years (QALYs) gained were calculated for over a 100-year time horizon with discount rate of 3%.

RESULT

The model indicated that the routine 4vHPV vaccination and the routine plus catch-up 4vHPV vaccination strategies could prevent approximately 434,130 and 472,502 cumulative cases of cervical cancer, 182,234 and 199,068 cumulative deaths from cervical cancer and 12,708,349 and 13,641,398 cumulative cases of HPV 6/11 related genital warts, respectively, when compared with no vaccination over 100 years. The estimated cost per QALY gained (ICER) when compared to no vaccination in Thailand was 8,370 THB/QALY for the routine vaccination and 9,650 THB/QALY for the routine with catch-up vaccination strategy.

CONCLUSION

Considering the recommended threshold of 160,000 THB/QALY for Thailand, the implementation of the routine 4vHPV vaccination either alone or plus the catch-up vaccination was cost-effective as compared to the cervical cancer screening only.

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.

Vaccine Prices: A Systematic Review of Literature

Vaccines are among the most vital interventions to control and reduce the morbidity and mortality worldwide. In accessing vaccines, pricing is usually the single most important deciding element. However, there is a scarcity of the literature on the vaccines pricing. The current study aims to review vaccine prices from the published literature and to evaluate factors that impact the pricing of vaccines. The literature (from 2015–2020) was reviewed to identify the original research articles. Systematic searches were conducted across the five databases including, Google Scholar, PubMed, Science Direct, Scopus and Springer Link. Literature search yielded 23,626 articles, of which 7351 were screened and 7310 articles were excluded based on title and abstracts relevance. The 41 studies were selected for full text review and 4 studies were found to meet the inclusion criteria. The included studies discussed vaccine prices for childhood vaccines, for Human Papilloma Virus (HPV) in US, China and in Europe. One study detailed the various scenarios of the HPV vaccines pricing. It was found that recently introduced vaccines have higher prices owing to the involvement of technology and research for their manufacture. However, prices tended to decrease over some maturation in price and by the involvement of Global Alliance for Vaccine Initiative (GAVI) and other allies. The prices of vaccines in China were much lower than the other high-income countries and the prices offered through United Nations Children’s Fund (UNICEF), mainly due to the large scale of demand in China. The affordable prices of vaccines were related to delicate procedures involving multiple stakeholders and a shorter duration of contract. This review systematically evaluated the literature and identified key factors that could impact vaccines pricing. The prices were higher for the newly introduced vaccines into the market. However, with the price maturation, there was a decline in the pricing and affordable prices could be achieved through tender pricing and involvement of GAVI and other allies.

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.

Knowledge of Human Papillomavirus, Risk of Anogenital Cancers, and Benefits of Vaccination: A Medical Student Survey in Saudi Arabia

Background Human papillomavirus (HPV) is one of the most common sexually transmitted infections and plays a significant role in the development of anogenital cancer. However, there is a lack of awareness on the subject in Saudi Arabia and very few documented studies on the knowledge and awareness of medical students regarding HPV. Methods A cross-sectional study utilizing a survey distributed to 306 medical students of both genders was utilized. A self-administrated questionnaire was distributed to all participants to assess their knowledge of HPV and their attitude towards HPV vaccination. Data analysis was performed using SPSS v 24 (IBM Corp., Armonk, NY, US) and RStudio v 1.14 (Boston, US). Results Most of the respondents (72.2%) had a high level of knowledge regarding HPV, with 47.84% of the respondents being aware of the risks associated with HPV and having a positive attitude towards HPV. Female respondents had better awareness and knowledge as compared to male students. However, there was a lack of knowledge regarding the duration and frequency of HPV infection, which could have an effect on the attitude of medical students towards vaccination. The results obtained by using Pearson's correlation coefficient showed a statistically significant correlation between the attitude towards HPV and the knowledge regarding HPV (p-value < 0.05). Conclusion Better awareness and knowledge regarding HPV and its risks correlate with a better attitude towards HPV. The medical school curriculum was found to be a primary source of information for students on the awareness of HPV. Therefore, more about HPV and the benefits associated with vaccination against HPV should be included in the curriculum in all years of medical school.

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.

Assessing Rationality in Discrete Choice Experiments in Health: An Investigation into the Use of Dominance Tests

BACKGROUND

Dominance tests are often applied to test for the rationality in the choice behavior of participants in discrete choice experiments (DCEs).

OBJECTIVES

To examine how dominance tests have been implemented in recent DCE applications in health and discuss their theoretical and empirical interpretation.

METHODS

Health-related DCEs published in 2015 were reviewed for the inclusion of tests on choice behavior. For studies that implemented a dominance test, information on application and interpretation of the test was extracted. Authors were contacted for test choice sets and observed proportions of subjects who chose the dominated option. Coefficients corresponding to the choice set were extracted to estimate the expected probability of choosing the dominated option with a logistic model and compared with the observed proportion. The theoretical range of expected probabilities of possible dominance tests was calculated.

RESULTS

Of 112 health-related DCEs, 49% included at least one test for choice behavior; 28 studies (25%) included a dominance test. The proportion of subjects in each study who chose the dominated option ranged from 0% to 21%. In 46% of the studies, the dominance test led to the exclusion of participants. In the 15 choice sets that were analyzed, 2 had larger proportions of participants choosing the dominated option than expected (P < 0.05).

CONCLUSIONS

Although dominance tests are frequently applied in DCEs, there is no consensus on how to account for them in data analysis and interpretation. Comparison of expected and observed proportions of participants failing the test might be indicative of DCE quality.

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.

Mothers' Preferences and Willingness to Pay for Human Papillomavirus Vaccination for Their Daughters: A Discrete Choice Experiment in Hong Kong

OBJECTIVES

To determine the preference of mothers in Hong Kong and their willingness to pay (WTP) for human papillomavirus (HPV) vaccination for their daughters.

METHOD

A discrete choice experiment survey with a two-alternative study design was developed. Data were collected from pediatric specialist outpatient clinics from 482 mothers with daughters aged between 8 and 17 years. Preferences of the four attributes of HPV vaccines (protection against cervical cancer, protection duration, side effects, and out-of-pocket costs) were evaluated. The marginal and overall WTP were estimated using multinomial logistic regression. A subgroup analysis was conducted to explore the impact of socioeconomic factors on mothers' WTP.

RESULTS

Side effects, protection against cervical cancer, protection duration, and out-of-pocket cost determined the decision to receive or not receive the vaccine. All attributes had a statistically significant effect on the preference of and the WTP for the vaccine. Maximum WTP for ideal vaccines (i.e., 100% protection, lifetime protection duration, and 0% side effects) was HK$8976 (US $1129). The estimated WTP for vaccines currently available was HK$1620 (US $208), lower than the current market price. Among those who had a monthly household income of more than HK$100,000 (US $12,821), the WTP for vaccines currently offered was higher than the market price.

CONCLUSIONS

This study provides new data on how features of the HPV vaccine are viewed and valued by mothers by determining their perception of ideal or improved and current vaccine technologies. These findings could contribute to future policies on the improvement of HPV vaccine and be useful for the immunization service in Hong Kong.

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.

Knowledge about Human Papillomavirus and Cervical Cancer: Predictors of HPV Vaccination among Dental Students

Background: The objective of this study is to determine the influence of dental students’ knowledge and attitude regarding human papillomavirus infection of cervical cancer on willingness to pay for vaccination. Basic research design: A convenience sampling method was used. The minimal sample size of 136 was calculated using the Raosoft calculator with a 5 % margin of error and 95% confidence level. Participants: The study population were all final year dental students from the School of Dentistry. Methods: A self-administered questionnaire was used to measure knowledge levels and attitudes regarding human papillomavirus vaccination. Contingent valuation was conducted for willingness to pay for vaccination. Main outcome measures: The Center for Disease Control and Prevention has stated that human papillomavirus are associated with oropharynx cancer and the American Dental Association insist on expanding public awareness of the oncogenic potential of some HPV infections. Thus, as future dental practitioners, dental students should be aware of human papillomavirus and their links with cancer and the benefits of vaccination. Results: Knowledge on HPV and cervical cancer did not impact on attitudes towards vaccines. However, significant correlation existed between knowledge and willingness to pay for vaccination. Conclusions: Dental students’ knowledge on HPV and cervical cancer has no influence on their attitude towards HPV vaccines. However, their willingness to pay for HPV vaccination is influenced by their knowledge of cervical cancer and HPV vaccination.