Preferences for hospital quality in Zambia: results from a discrete choice experiment

This study reports on the results of a discrete choice experiment undertaken in Zambia to assess the factors influencing the demand for hospital care in Zambia, in particular the role of (perceived) quality and trade-offs between price and quality. Valuations of quality were evaluated for the treatment of two acute medical conditions, cerebral malaria in adults and acute pneumonia in children. Marginal utilities and willingness-to-pay for attributes of quality of hospital care were estimated, together with the influence of socioeconomic characteristics on these valuations and the extent of non-linearities in valuations of time and money. We find the technical quality of care, as represented by the thoroughness of examination, to be the most important quality attribute, followed by staff attitudes and drug availability. Valuations of examination thoroughness increase with increasing socioeconomic status. The disutility of cost was found to decrease with higher socioeconomic status, as was the value of drug availability. The implications of the findings for Zambian hospital sector reforms are discussed.     

Choosing vs. allocating: discrete choice experiments and constant‐sum paired comparisons for the elicitation of societal preferences

Background

There is growing evidence of a reluctance to allocate health care solely on the basis of maximizing quality‐adjusted life years (QALYs). Stated preference methods can be used to elicit preferences for efficiency vs. equity in the allocation of health‐care resources.

Objective

To compare discrete choice experiment (DCE) and constant‐sum paired comparison (CSPC) methods for eliciting societal preferences.

Methods

Over a series of choice pairs, DCE respondents allocated a fixed budget to one preferred group and CSPC respondents allocated budget percentages between the groups. Questionnaires were compared in terms of completion rates, preference consistency, dominant preferences and derived attribute importance.

Results

There was no significant difference in the proportions that rated the questionnaires somewhat or extremely difficult, but a significantly greater proportion completed the DCE compared to the CSPC. Preference consistency was also higher in the DCE. The incidence of dominant preferences, including for aggregate QALYs, was low and not significantly different between questionnaires. Similarly, no CSCP respondents equalized budgets or outcomes in every task. Final health state was the most important attribute in both questionnaires, but the rankings diverged for the other attributes. Notably, the total patients'' treated attribute was important in the CSPC but insignificant in the DCE, perhaps reflecting a ‘prominence effect’.

Conclusions

Despite lower completion rates and preference consistency, CSPC may offer advantages over DCE in eliciting preferences over the distribution of resources and/or outcomes as well as attribute levels, avoiding extreme ‘all‐or‐nothing’ distributions and possibly aligning respondent attention more closely with a societal perspective.     

Preferences for physician services in Ukraine: a discrete choice experiment

Evidence on preferences of Ukrainian consumers for healthcare improvements can help to design reforms that correspond to societal priorities. This study aims to elicit and to place monetary values on public preferences for out‐patient physician services in Ukraine. The method of discrete choice experiment is used on a sample of 303 respondents, representative of the adult Ukrainian population. The random effect logit model with interactions provides the best fit for the data and is used to calculate the marginal willingness to pay (MWTP) for quality and access improvements. At a sample level, there is no clear preference to pay formally rather than informally or vice versa. We also do not find that visiting a general practitioner is preferred over direct access to a medical specialist. However, there are differences between population groups. Quality‐related attributes of physician services appear important to respondents, especially the attitude of medical staff. Thus, interpersonal aspects of out‐patient care should be given priority in decisions about investments in quality improvements. Other aspects, that is social quality and access, are important as well but their improvement brings fewer social gains. Measures should be taken to eradicate the informal payment channels and to strengthen the gate‐keeping role of primary care. Copyright © 2014 John Wiley & Sons, Ltd.     

Eliciting the demand for long-term care coverage: a discrete choice modelling analysis

We evaluate the demand for long-term care (LTC) insurance prospects in a stated preference context, by means of the results of a choice experiment carried out on a representative sample of the Emilia-Romagna population. In this paper, these methods are first of all used in order to assess the relative importance of the characteristics that define hypothetical insurance programmes and to elicit the willingness to pay for some LTC coverage prospects. Moreover, thanks to the application of a nested logit specification with 'partial degeneracy', we are able to model the determinants of the preference for status quo situations where no systematic cover for LTC exists. On the basis of this empirical model, we test for the effects of a series of socio-demographic variables as well as personal and household health-state indicators.     

Testing the External Validity of a Discrete Choice Experiment Method: An Application to Latent Tuberculosis Infection Treatment

Objectives

To explore the external validity and predictive power of stated preferences obtained from a discrete choice experiment (DCE) by comparing the predicted behavior of respondents to their actual choices at an individual level.

Parental preferences for rotavirus vaccination in young children: A discrete choice experiment

Objective

This study aimed to identify characteristics that affect parental decisions about rotavirus vaccination, to determine the relative importance of those characteristics and subsequently to estimate vaccination coverage for different implementation strategies.

Methods

A Discrete choice experiment (DCE) questionnaire was sent to the parents of 1250 newborns aged 6 weeks (response rate 37.3%). Mixed-logit models were used to estimate the relative importance of the five included rotavirus vaccine and implementation characteristics; vaccine effectiveness, frequency of severe side effects, protection duration, the healthcare facility that administrates vaccination and out-of-pocket costs. Based on the utility functions of the mixed-logit model, the potential vaccination coverage was estimated for different vaccine scenarios and implementation strategies.

Results

All characteristics, except for healthcare facility that administrates vaccination, influenced parental willingness to vaccinate their newborn against rotavirus. Parents were willing to trade 20.2 percentage points vaccine effectiveness for the lowest frequency of severe side effects (i.e., 1 in 1,000,000) or 20.8 percentage points for a higher protection duration. Potential vaccination coverage ranged between 22.7 and 86.2%, depending on vaccine scenario (i.e., vaccine effectiveness and protection duration) and implementation strategy (i.e., out-of-pocket costs and healthcare facility that administrates vaccination).

Conclusions

When deciding about vaccination against rotavirus, parents are mostly driven by the out-of-pocket costs, vaccine effectiveness, protection duration, and frequency of severe side effects. The highest vaccination coverage is expected for a vaccine with high effectiveness and protection duration that is implemented within the current National Immunization Program context. Implementation of the same rotavirus vaccine in the free market will result in lowest coverage.     

Exploring the social value of health‐care interventions: a stated preference discrete choice experiment

Much of the literature on distributive preferences covers specific considerations in isolation, and recent reviews have suggested that research is required to inform on the relative importance of various key considerations. Responding to this research recommendation, we explore the distributive preferences of the general public using a set of generic social value judgments. We report on a discrete choice experiment (DCE) survey, using face‐to‐face interviews, in a sample of the general population (n=259). The context for the survey was resource allocation decisions in the UK National Health Service, using the process of health technology appraisal as an example. The attributes used covered health improvement, value for money, severity of health, and availability of other treatments, and it is the first such survey to use cost‐effectiveness in scenarios described to the general public. Results support the feasibility and acceptability of the DCE approach for the elicitation of public preferences. Choice data are used to consider the relative importance of changes across attribute levels, and to model utility scores and relative probabilities for the full set of combinations of attributes and levels in the experimental design used (n=64). Results allow the relative social value of health technology scenarios to be explored. Findings add to a sparse literature on ‘social’ preferences, and show that DCE data can be used to consider the strength of preference over alternative scenarios in a priority‐setting context. Copyright © 2008 John Wiley & Sons, Ltd.     

Measuring Patient Preferences for Colorectal Cancer Screening Using a Choice-Format Survey

OBJECTIVE: Colorectal cancer (CRC) screening uptake remains poor. Until we understand patient motivation and preferences for undertaking screening, it is unlikely the uptake will be optimal. Our objective is to examine patient preferences for CRC screening modalities and uptake rates using utility-based methods. METHODS: The preference survey was mailed to a random sample of Canadian subjects aged 40 to 60 years from a primary care network. A fractional factorial experimental design maximized D-efficiency and included four blocks with 12 choice tasks in a conditional two-step design, two-alternative discrete choice format with five screening attributes (process, pain, preparation, sensitivity, and specificity). Bivariate probit regression analysis was used to estimate patient preferences for attributes, choice probabilities for alternative modalities and expected rates of uptake. RESULTS: Five hundred forty-seven of 1047 surveys were returned. Almost 30% of respondents preferred no screening. The most preferred test attribute levels were noninvasive process (e.g., CT), no preparation, no pain, 100% specificity, and 90% sensitivity. Accuracy-related attributes were more important than test process-related attributes. Virtual colonoscopy was the most preferred, followed by colonoscopy, barium enema, sigmoidoscopy, and fecal DNA testing, based on simulated choice probability estimates. Fecal occult blood testing (FOBT) was least preferred. Adjusted screening uptake rate estimates showed the greatest impact (42% increase) would be achieved if all CRC screening modalities were available rather than FOBT alone. CONCLUSIONS: Our findings emphasize the important role of patient preferences for no screening and in selecting alternative CRC screening modalities. CRC screening implementation in Canada should consider patient preferences to optimize uptake.     

Using stated preference discrete choice modelling to evaluate the introduction of varicella vaccination

Applications of stated preference discrete choice modelling (SPDCM) in health economics have been used to estimate consumer willingness to pay and to broaden the range of consequences considered in economic evaluation. This paper demonstrates how SPDCM can be used to predict participation rates, using the case of varicella (chickenpox) vaccination. Varicella vaccination may be cost effective compared to other public health programs, but this conclusion is sensitive to the proportion of the target population immunised. A choice experiment was conducted on a sample of Australian parents to predict uptake across a range of hypothetical programs. Immunisation rates would be increased by providing immunisation at no cost, by requiring it for school entry, by increasing immunisation rates in the community and decreasing the incidence of mild and severe side effects. There were two significant interactions; price modified the effect of both support from authorities and severe side effects. Country of birth was the only significant demographic characteristic. Depending on aspects of the immunisation program, the immunisation rates of children with Australian-born parents varied from 9% to 99% while for the children with parents born outside Australia they varied from 40% to 99%. This demonstrates how SPDCM can be used to understand the levels of attributes that will induce a change in the decision to immunise, the modification of the effect of one attribute by another, and subgroups in the population. Such insights can contribute to the optimal design and targeting of health programs.     

Preferences for a third‐trimester ultrasound scan in a low‐risk obstetric population: a discrete choice experiment

Objective

Establish maternal preferences for a third‐trimester ultrasound scan in a healthy, low‐risk pregnant population.

Design

Cross‐sectional study incorporating a discrete choice experiment.

Setting

A large, urban maternity hospital in Northern Ireland.

Participants

One hundred and forty‐six women in their second trimester of pregnancy.

Methods

A discrete choice experiment was designed to elicit preferences for four attributes of a third‐trimester ultrasound scan: health‐care professional conducting the scan, detection rate for abnormal foetal growth, provision of non‐medical information, cost. Additional data collected included age, marital status, socio‐economic status, obstetric history, pregnancy‐specific stress levels, perceived health and whether pregnancy was planned. Analysis was undertaken using a mixed logit model with interaction effects.

Main outcome measures

Women's preferences for, and trade‐offs between, the attributes of a hypothetical scan and indirect willingness‐to‐pay estimates.

Results

Women had significant positive preference for higher rate of detection, lower cost and provision of non‐medical information, with no significant value placed on scan operator. Interaction effects revealed subgroups that valued the scan most: women experiencing their first pregnancy, women reporting higher levels of stress, an adverse obstetric history and older women.

Conclusions

Women were able to trade on aspects of care and place relative importance on clinical, non‐clinical outcomes and processes of service delivery, thus highlighting the potential of using health utilities in the development of services from a clinical, economic and social perspective. Specifically, maternal preferences exhibited provide valuable information for designing a randomized trial of effectiveness and insight for clinical and policy decision makers to inform woman‐centred care.     

The introduction of integrated out-of-hours arrangements in England: a discrete choice experiment of public preferences for alternative models of care

OBJECTIVE: To establish which generic attributes of general practice out-of-hours health services are important to the public. METHODS: A discrete choice experiment postal survey conducted in three English general practitioner (GP) co-operatives. A total of 871 individuals aged 20-70 years registered with a GP. Outcomes were preferences for, and trade-offs between: time to making initial contact, time waiting for advice/treatment, informed of expected waiting time, type of contact, professional providing advice, chance contact relieves anxiety, and utility estimates for valuing current models of care. RESULTS: Response rate was 37%. Respondents valued out-of-hours contact for services for reducing anxiety but this was not the only attribute of importance. They had preferences for the way in which services were organized and valued information about expected waiting time, supporting findings from elsewhere. Participants were most willing to make trade-offs between waiting time and professional person. Of the predicted utility for three models of care utility was higher for fully integrated call management. CONCLUSIONS: Greater utility might be achieved if existing services are re-configured more in line with the government's fully integrated call management model. Because the attributes were described in generic terms, the findings can be applied more generally to the plethora of models that exist (and many that might exist in the future). The approach used is important for achieving greater public involvement in how health services develop. Few experiments have elicited public preferences for health services in the UK to date. This study showed valid preferences were expressed but there were problems obtaining representative views from the public.     

Girls’ preferences for HPV vaccination: A discrete choice experiment

A discrete choice experiment was developed to investigate if girls aged 12–16 years make trade-offs between various aspects of human papillomavirus (HPV) vaccination, and to elicit the relative weight that girls’ place on these characteristics. Degree of protection against cervical cancer, protection duration, risk of side-effects, and age of vaccination, all proved to influence girls’ preferences for HPV vaccination. We found that girls were willing to trade-off 38% protection against cervical cancer to obtain a lifetime protection instead of a protection duration of 6 years, or 17% to obtain an HPV vaccination with a 1 per 750,000 instead of 1 per 150,000 risk of serious side-effects. We conclude that girls indeed made a trade-off between degree of protection and other vaccine characteristics, and that uptake of HPV vaccination may change considerably if girls are supplied with new evidence-based information about the degree of protection against cervical cancer, the protection duration, and the risk of serious side-effects.     

Comparing welfare estimates from payment card contingent valuation and discrete choice experiments

This study presents the first comparison of willingness to pay estimates derived from the payment card (PC) contingent valuation and discrete choice experiment (DCE) methods. A within-sample experiment was used to elicit women's preferences for Chlamydia screening. The willingness to pay estimate derived from the DCE was larger than that derived from the PC. To investigate why the willingness to pay estimates were different, a range of validity tests were conducted. Both methods produced theoretically valid results, and there was no difference in the reported difficulty of completing the tasks. Evidence of a prominence effect was found in the PC responses. Responses to the DCE satisfied tests of non-satiation. Responses to both methods were compared with revealed preference data. There were significant differences between stated screening intention in both methods and actual screening uptake. Future work should address the external validity of stated preference methods.     

How to make rural jobs more attractive to health workers. Findings from a discrete choice experiment in Tanzania

The geographical imbalance of the health workforce in Tanzania represents a serious problem when it comes to delivering crucial health services to a large share of the population. This study provides new quantitative information about how to make jobs in rural areas more attractive to newly educated clinical officers (COs). A unique data set stemming from a discrete choice experiment with CO finalists in Tanzania is applied. The results show that offering continuing education after a certain period of service is one of the most powerful recruitment instruments the authorities have available. Increased salaries and hardship allowances will also substantially increase recruitment in rural areas. Offers of decent housing and good infrastructure, including the provision of equipment, will increase recruitment to rural remote areas but not as much as higher wages and offers of education. Women are less responsive to pecuniary incentives and are more concerned with factors that directly allow them to do a good job, while those with parents living in a remote rural area are generally less responsive to the proposed policies. When the willingness to help other people is a strong motivating force, policies that improve the conditions for helping people appear particularly effective. Copyright © 2010 John Wiley & Sons, Ltd.     

Empirical investigation of experimental design properties of discrete choice experiments in health care

Experimental design is critical to valid inference from the results of discrete choice experiments (DCEs). In health economics, DCEs have placed limited emphasis on experimental design, typically employing relatively small fractional factorial designs, which allow only strictly linear additive utility functions to be estimated. The extensive literature on optimal experimental design outside health economics has proposed potentially desirable design properties, such as orthogonality, utility balance and level balance. However, there are trade-offs between these properties and emphasis on some properties may increase the random variability in responses, potentially biasing parameter estimates.This study investigates empirically the design properties of DCEs, in particular, the optimal method of combining alternatives in the choice set. The study involves a forced choice between two alternatives (treatment and non-treatment for a hypothetical health care condition), each with three, four-level, alternative-specific attributes. Three experimental design approaches are investigated: a standard six-attribute, orthogonal main effects design; a design that combines alternatives to achieve utility balance, ensuring no alternatives are dominated; and a design that combines alternatives randomly. The different experimental designs did not impact on the underlying parameter estimates, but imposing utility balance increases the random variability of responses.     

Eliciting preferences for medical devices in South Korea: A discrete choice experiment

This study aims to identify the attributes that contribute to the value of medical devices and quantify the relative importance of them using a discrete choice experiment. Based on a literature review and expert consultation, seven attributes and their levels were identified—severity of disease (2), availability of substitutes (2), improvement in procedure (3), improvement in clinical outcomes (2), increase in survival (2), improvement in quality of life (3), and cost (4). Among 576 hypothetical profiles, optimal choice sets with 20 choices were developed and experts experienced in health technology assessment and reimbursement decision making in South Korea were surveyed. A total of 102 respondents participated in the survey. The results of the random-effect probit model showed that among the seven attributes, six, except for improvement in procedure, had a significant impact on respondents’ choices on medical devices. Respondents were willing to pay the highest amount for devices that provided substantial improvements in quality of life, followed by increased survival, improved clinical outcome, treatment without substitutes, and technology for treating severe diseases. The findings of this experiment will inform decision-makers of the relative importance of the criteria and help them in reimbursement decision making of medical devices.     

'Irrational' stated preferences: a quantitative and qualitative investigation

Individuals' rationality has been a key issue long debated in Economics. While normative theories establish the way 'rational' consumers should behave, many empirical studies have documented numerous systematic violations of normative principles. This has led some to question the validity of classic economic models as an adequate approximation of individuals' real decision-making. This paper aims to shed more light on this debate. A stated preference choice experiment was set up to test rational choice properties. Attention was given to the extent to which satisfaction of such tests is related to both the complexity of the design, and subject characteristics. Quantitative and qualitative methods are applied. The majority of respondents passed the rationality tests. Satisfaction of the tests was sensitive to normatively irrelevant factors such as the complexity of the task and demographic characteristics. A significant proportion of those individuals who 'failed' seem to have reformulated the experiment in some way in their mental process. Implications for the design and analyses of future DCEs are discussed.     

Using discrete choice experiments to understand preferences for quality of life. Variance-scale heterogeneity matters

Health services researchers are increasingly using discrete choice experiments (DCEs) to model a latent variable, be it health, health-related quality of life or utility. Unfortunately it is not widely recognised that failure to model variance heterogeneity correctly leads to bias in the point estimates. This paper compares variance heterogeneity latent class models with traditional multinomial logistic (MNL) regression models. Using the ICECAP-O quality of life instrument which was designed to provide a set of preference-based general quality of life tariffs for the UK population aged 65+, it demonstrates that there is both mean and variance heterogeneity in preferences for quality of life, which covariate-adjusted MNL is incapable of separating. Two policy-relevant mean groups were found: one group that particularly disliked impairments to independence was dominated by females living alone (typically widows). Males who live alone (often widowers) did not display a preference for independence, but instead showed a strong aversion to social isolation, as did older people (of either sex) who lived with a spouse. Approximately 6–10% of respondents can be classified into a third group that often misunderstood the task. Having a qualification of any type and higher quality of life was associated with smaller random component variances. This illustrates how better understanding of random utility theory enables richer inferences to be drawn from discrete choice experiments. The methods have relevance for all health studies using discrete choice tasks to make inferences about a latent scale, particular QALY valuation exercises that use DCEs, best-worst scaling and ranking tasks.