Stubbing out hypothetical bias: improving tobacco market predictions by combining stated and revealed preference data

Exploring the Factors that Drive Clinical Negligence Claims: Stated Preferences of Those Who Have Experienced Unintended Harm

BACKGROUND

Better understanding of the factors that influence patients to make a financial claim for compensation is required to inform policy decisions. This study aimed to assess the relative importance of factors that influence those who have experienced a patient safety incident (PSI) to make a claim for compensation.

METHOD

Participants completed an online discrete choice experiment (DCE) involving 10 single profile tasks where they chose whether or not to file a claim. DCE data were modelled using logistic, mixed logit and latent class regressions; scenario analyses, external validity, and willingness to accept were also conducted.

RESULTS

A total of 1029 participants in the United Kingdom responded to the survey. An appropriate apology and a satisfactory investigation reduced the likelihood of claiming. Respondents were more likely to claim if they could hold those responsible accountable, if the process was simple and straightforward, if the compensation amount was higher, if the likelihood of compensation was high or uncertain, if the time to receive a decision was quicker, and if they used the government compensation scheme. Men are more likely to claim for low impact PSIs.

DISCUSSION AND CONCLUSIONS

The actions taken by the health service after a PSI, and people's perceptions about the probability of success and the size of potential reward, can influence whether a claim is made. Results show the importance of giving an appropriate apology and conducting a satisfactory investigation. This stresses the importance around how patients are treated after a PSI in influencing the clinical negligence claims that are made.

Identifying Preferred Features of Weight Loss Programs for Adults With or at Risk of Type 2 Diabetes: A Discrete Choice Experiment With 3,960 Adults in the U.K

OBJECTIVE

To understand preferences for features of weight loss programs among adults with or at risk of type 2 diabetes in the U.K.

RESEARCH DESIGN AND METHODS

We conducted a discrete choice experiment with 3,960 U.K. adults living with overweight (n = 675 with type 2 diabetes). Preferences for seven characteristics of weight loss programs were analyzed. Simulations from choice models using the experimental data predicted uptake of available weight loss programs. Patient groups comprising those who have experience with weight loss programs, including from minority communities, informed the experimental design.

RESULTS

Preferences did not differ between individuals with and without type 2 diabetes. Preferences were strongest for type of diet. Healthy eating was most preferred relative to total diet replacement (odds ratio [OR] 2.24; 95% CI 2.04-2.44). Individual interventions were more popular than group interventions (OR 1.40; 95% CI 1.34-1.47). Participants preferred programs offering weight loss of 10-15 kg (OR 1.37; 95% CI 1.28-1.47) to those offering loss of 2-4 kg. Online content was preferred over in-person contact (OR 1.24; 95% CI 1.18-1.30). There were few differences in preferences by gender or ethnicity, although weight loss was more important to women than to men, and individuals from ethnic minority populations identified more with programs where others shared their characteristics. Modeling suggested that tailoring programs to individual preferences could increase participation by ∼17 percentage points (68% in relative terms).

CONCLUSIONS

Offering a range of weight loss programs targeting the preferred attributes of different patient groups could potentially encourage more people to participate in weight loss programs and support those living with overweight to reduce their weight.

Economic research in waterpipe tobacco smoking: reflections on data, demand, taxes, equity and health modelling

Economic evaluation of tobacco control policies is common in high-income settings and mainly focuses on cigarette smoking. Evidence suggests that increasing the excise tax of tobacco products is a consistently effective tool for reducing tobacco use and is an efficient mechanism for increasing government revenues. However, less research has been conducted in low/middle-income countries where other tobacco forms are common. This paper presents insights from our work on the economics of waterpipe tobacco smoking conducted in the Eastern Mediterranean Region where waterpipe smoking originated and is highly prevalent. The specific areas related to economics of waterpipe smoking considered herein are: price elasticity, taxation, government revenue, expenditure and healthcare costs. This paper aims to provide practical guidance for researchers investigating the economics of waterpipe tobacco with potential implications for other novel tobacco products. We present lessons learnt across five thematic areas: data, demand, taxes, equity and health modelling. We also highlight knowledge gaps to be addressed in future research. Research implications include designing comprehensive assessment tools that investigate heterogeneity in waterpipe smoking patterns; accounting for cross-price elasticity of demand with other tobacco products; exploring the change in waterpipe tobacco smoking in response to a tax increase and analysing the equity impact of waterpipe tobacco control interventions.

Harm reduction for smokers with little to no quit interest: can tobacco policies encourage switching to e-cigarettes?

OBJECTIVE

A pressing tobacco policy concern is how to help smokers who have little interest in quitting cigarettes, a group that often suffers severe health consequences. By switching from cigarettes to e-cigarettes, they could obtain nicotine, potentially with less harm. We examined if policy-relevant attributes of cigarettes/e-cigarettes might encourage these smokers to switch to e-cigarettes.

METHODS

An online survey and discrete choice experiment on a nationally-representative sample of adult smokers in the US who reported low interest in quitting (n=2000). We modelled preference heterogeneity using a latent class, latent variable model. We simulated policies that could encourage switching to e-cigarettes.

RESULTS

Participants formed two latent classes: (1) those with very strong preferences for their own cigarettes; and (2) those whose choices were more responsive to policies. The latter group's choices were only somewhat responsive to menthol cigarette bans and taxes; the former group's choices were unresponsive.

CONCLUSIONS

The policies studied seem unlikely to encourage harm reduction for individuals with little interest in quitting smoking.

Can decision field theory enhance our understanding of health-based choices? Evidence from risky health behaviors

Discrete choice models are almost exclusively estimated assuming random utility maximization (RUM) is the decision rule applied by individuals. Recent studies indicate alternative behavioral assumptions may be more appropriate in health. Decision field theory (DFT) is a psychological theory of decision-making, which has shown promise in transport research. This study introduces DFT to health economics, empirically comparing it to RUM and random regret minimization (RRM) in risky health settings, namely tobacco and vaccine choices. Model fit, parameter ratios, choice shares, and elasticities are compared between RUM, RRM and DFT. Test statistics for model differences are derived using bootstrap methods. Decision rule heterogeneity is investigated using latent class models, including novel latent class DFT models. Tobacco and vaccine choice data are better explained with DFT than with RUM or RRM. Parameter ratios, choice shares and elasticities differ significantly between models. Mixed results are found for the presence of decision rule heterogeneity. We conclude that DFT shows promise as a behavioral assumption that underpins the estimation of discrete choice models in health economics. The significant differences demonstrate that care should be taken when choosing a decision rule, but further evidence is needed for generalizability beyond risky health choices.

Can healthcare choice be predicted using stated preference data? The role of model complexity in a discrete choice experiment about colorectal cancer screening

INTRODUCTION

The validity of discrete choice experiments (DCEs) is crucial to its usage in healthcare decision-making, but there is only a limited number of health contexts in which external validity is demonstrated. This study aims to assess the internal and external validity of the DCE in the context of colorectal cancer (CRC) screening, and gather insights into the discrepancy between stated and revealed preferences.

METHODS

Stated and revealed preferences were elicited on an individual level from Dutch residents eligible for CRC screening in a DCE and a field experiment, respectively (N = 568). To identify the determinants of CRC screening participation and their relative importance, five random utility maximisation models that varied in complexity were used. We assessed the accuracy with which the models based on stated preferences predict individual-level screening choice in a holdout task (internal validity) and in the actual screening choice (external validity). Insights into the discrepancy between stated and revealed preferences were gathered by comparing groups of respondents.

RESULTS

Our findings show high internal and external validity. Choices could be accurately predicted for 95% of the respondents in the holdout task, and 90% in the actual screening choice. When scale and preference heterogeneity were taken into account model fit improved; individual-level prediction accuracy slightly increased for the holdout task but not for the actual screening choice. Respondents for whom stated preferences matched revealed preferences were generally in better health and found the GP's support for their screening decision more important.

DISCUSSION

Evidence was found that revealed preferences can be predicted accurately on an individual level. Incorporating heterogeneity improved internal validity but not external validity. Differences between stated and revealed preferences can be attributed to respondents' health and the support of their GP. We suggest researchers to continue investigating the internal and external validity of discrete choice experiments, and the role of model complexity.

The Economics of Tobacco Regulation: A Comprehensive Review

Tobacco regulation has been a major component of health policy in the developed world since the UK Royal College of Physicians' and the US Surgeon General's reports in the 1960s. Such regulation, which has intensified in the past two decades, includes cigarette taxation, place-based smoking bans in areas ranging from bars and restaurants to workplaces, and regulations designed to make tobacco products less desirable. More recently, the availability of alternative products, most notably e-cigarettes, has increased dramatically, and these products are just starting to be regulated. Despite an extensive body of research on tobacco regulations, there remains substantial debate regarding their effectiveness, and ultimately, their impact on economic welfare. We provide the first comprehensive review of the state of research in the economics of tobacco regulation in two decades.

The demand for a COVID-19 vaccine

Taking willingness to pay as primitive, this paper establishes an analytical framework for demand estimation, where the estimator is robust to endogeneity of price. Applying the framework, this paper then estimates demand functions for a COVID-19 vaccine and compute the consumer surplus in both China and the UAE. We find that the price elasticities of demand are mostly greater than one in both countries. An elastic demand suggests subsidy is likely to be successful in promoting vaccination. The consumer surplus is sizeable, around 58 billion US$ in China and 646 million US$ in the UAE. The figures can inform policymakers in assessing their vaccine programs.

Utility maximization versus regret minimization in health choice behavior: Evidence from four datasets

Choice models in health are almost exclusively based on the neoclassical economic paradigm of utility maximization. Recently developed choice models have captured and shown empirical support for regret minimization as an alternative decision rule. In health economics, recent applications of RRM models indicate that individuals making health-based choices may exhibit regret minimization-type behavior. In this paper, we build on this research using a more flexible model that allows for heterogeneous decision rules, separately from preference heterogeneity, and comparing it to models that assume single decision rules. We use four datasets from diverse settings in which individuals make health choices: tobacco markets, genomic testing, and HIV prevention. We found that, if a one-size-fits-all rule is applied, then utility maximization was preferable to regret minimization for these datasets. However, we also find that individuals apply varying decision rules in similar proportions in these health settings, suggesting that models for heterogeneous decision rules were needed to capture these behaviors in these settings.

Strategies to increase downloads of COVID-19 exposure notification apps: A discrete choice experiment

Exposure notification apps have been developed to assist in notifying individuals of recent exposures to SARS-CoV-2. However, in several countries, such apps have had limited uptake. We assessed whether strategies to increase downloads of exposure notification apps should emphasize improving the accuracy of the apps in recording contacts and exposures, strengthening privacy protections and/or offering financial incentives to potential users. In a discrete choice experiment with potential app users in the US, financial incentives were more than twice as important in decision-making about app downloads, than privacy protections, and app accuracy. The probability that a potential user would download an exposure notification app increased by 40% when offered a $100 reward to download (relative to a reference scenario in which the app is free). Financial incentives might help exposure notification apps reach uptake levels that improve the effectiveness of contact tracing programs and ultimately enhance efforts to control SARS-CoV-2. Rapid, pragmatic trials of financial incentives for app downloads in real-life settings are warranted.

Impact of Little Cigars and Cigarillos Packaging Features on Product Preference

Background: We conducted a discrete choice experiment (DCE) among young adult cigarette smokers in the period July–August 2018 to examine their preference for cigarillos in response to various packaging-related attributes, including flavor, flavor description, quality descriptors, pack size, and prices. Methods: A convenience sample of 566 US young adult cigarette smokers aged 18–34, among whom 296 were current little cigar and cigarillo (LCC) smokers, were recruited using Facebook ads and invited to participate in an online (Qualtrics) tobacco survey containing DCE and tobacco use questions. In the experiment, participants chose among two cigarillo products or “neither” (opt-out). Results: We analyzed preferences for LCCs using multinomial, nested, random parameter logit models. Results showed that young adult cigarette smokers preferred grape over menthol, tobacco/regular, and wine flavors; “color only” and “color and text” flavor depictions over text only; “smooth” and “sweet” quality descriptors over “satisfying”; and larger pack sizes and lower prices. Conclusions: Regulating packaging-related features will impact LCC choices among US young adult smokers. FDA regulation over these packaging-related features may impact LCC use among young adult smokers.

The Impact of Environmental Sustainability Labels on Willingness-to-Pay for Foods: A Systematic Review and Meta-Analysis of Discrete Choice Experiments

Food production is a major contributor to environmental damage. More environmentally sustainable foods could incur higher costs for consumers. In this review, we explore whether consumers are willing to pay (WTP) more for foods with environmental sustainability labels ('ecolabels'). Six electronic databases were searched for experiments on consumers' willingness to pay for ecolabelled food. Monetary values were converted to Purchasing Power Parity dollars and adjusted for country-specific inflation. Studies were meta-analysed and effect sizes with confidence intervals were calculated for the whole sample and for pre-specified subgroups defined as meat-dairy, seafood, and fruits-vegetables-nuts. Meta-regressions tested the role of label attributes and demographic characteristics on participants' WTP. Forty-three discrete choice experiments (DCEs) with 41,777 participants were eligible for inclusion. Thirty-five DCEs (n = 35,725) had usable data for the meta-analysis. Participants were willing to pay a premium of 3.79 PPP$/kg (95%CI 2.7, 4.89, p ≤ 0.001) for ecolabelled foods. WTP was higher for organic labels compared to other labels. Women and people with lower levels of education expressed higher WTP. Ecolabels may increase consumers' willingness to pay more for environmentally sustainable products and could be part of a strategy to encourage a transition to more sustainable diets.

Stated versus revealed preferences: An approach to reduce bias

Stated preference (SP) survey responses may not predict actual behavior, leading to hypothetical bias. We developed an approach that harnesses large-scale routine data to help SP surveys provide more accurate estimates of revealed preferences (RPs), within a study which elicited preferences for alternative changes to the blood service in England. The SP survey responses were used to predict the mean number of annual whole blood donations. Ex ante, the iterative survey design estimated hypothetical bias by contrasting pilot SP survey responses (N = 1254), with individually linked data on RPs, to inform the main SP survey design (N = 25,187). Ex post, the analysis recognized mediation of the relationship between SP and RP when blood donation is deferred. The pilot survey reported that donors' intended donation frequency of 3.2 (men) and 2.6 (women) times per year, exceeded their actual frequency by 41% and 30% respectively. Choice scenario attributes for the main SP survey were then modified, and over-prediction subsequently decreased to 34% for men and 16% for women. The mediating effect of deferrals explained 29% (men) and 86% (women) of the residual discrepancy between SP and RP. Future studies can use this approach to reduce hypothetical bias, and provide more accurate predictions for decision-making.

Kicking the habit is hard: A hybrid choice model investigation into the role of addiction in smoking behavior

Use of choice models is growing rapidly in tobacco research. These models are being used to answer key policy questions. However, certain aspects of smokers' choice behavior are not well understood. One such feature is addiction. Here, we address this issue by modeling data from a choice experiment on the US smokers. We model addiction using a latent variable. We use this latent variable to understand the relationship between choices and addiction, giving attention to nicotine levels. We find that more addicted smokers have stronger preferences for cigarettes and are unwilling to switch to e-cigarettes. Addicted smokers value nicotine in tobacco products to a much greater extent than those that are less addicted. Lastly, we forecast short-term responses to lowering nicotine levels in cigarettes. The results suggest that current nicotine-focused policies could be effective at encouraging addicted smokers to less harmful products and lead to substantial public health gains.

Mostly harmless regulation? Electronic cigarettes, public policy, and consumer welfare

Electronic cigarettes are a less harmful alternative to combustible cigarettes. We analyze data on e-cigarette choices in an online experimental market. Our data and mixed logit model capture two sources of consumer optimization errors: overestimates of the relative risks of e-cigarettes and present bias. Our novel data and policy analysis make three contributions. First, our predictions about e-cigarette use under counterfactual policy scenarios provide new information about current regulatory tradeoffs. Second, we provide empirical evidence about the role consumer optimization errors play in tobacco product choices. Third, we contribute to behavioral welfare analysis of policies that address individual optimization errors. Compared with standard cost-benefit analysis, our behavioral welfare economics analysis leads to much larger estimates of the costs of policies that discourage e-cigarette use or the benefits of policies that encourage e-cigarette use.

Measuring commissioners' willingness-to-pay for community based childhood obesity prevention programmes using a discrete choice experiment

Background

In the UK, rates of childhood obesity remain high. Community based programmes for child obesity prevention are available to be commissioned by local authorities. However, there is a lack of evidence regarding how programmes are commissioned and which attributes of programmes are valued most by commissioners. The aim of this study was to determine the factors that decision-makers prioritise when commissioning programmes that target childhood obesity prevention.

Methods

An online discrete choice experiment (DCE) was used to survey commissioners and decision makers in the UK to assess their willingness-to-pay for childhood obesity programmes.

Results

A total of 64 commissioners and other decision makers completed the DCE. The impact of programmes on behavioural outcomes was prioritised, with participants willing to pay an extra £16,600/year if average daily fruit and vegetable intake increased for each child by one additional portion. Participants also prioritised programmes that had greater number of parents fully completing them, and were willing to pay an extra £4810/year for every additional parent completing a programme. The number of parents enrolling in a programme (holding the number completing fixed) and hours of staff time required did not significantly influence choices.

Conclusions

Emphasis on high programme completion rates and success increasing children’s fruit and vegetable intake has potential to increase commissioning of community based obesity prevention programmes.