iSAY (incentives for South African youth): Stated preferences of young people living with HIV

Attribute Development in Health-Related Discrete Choice Experiments: A Systematic Review of Qualitative Methods and Techniques to Inform Quantitative Instruments

OBJECTIVES

This review sought to identify the qualitative methods and techniques that researchers have used in the past decade to develop attributes and inform health-related discrete choice experiments (DCEs) surveys from a patient perspective.

METHODS

The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for reporting systematic reviews. An adapted appraisal tool following guidelines for reporting qualitative research for quantitative instruments and criteria for attribute development in DCEs was applied for quality assessment and data extraction. A narrative approach was used to synthesize data. This examination included consideration of issues pertaining to sampling, data collection, data analysis, attribute list reduction, wording, methodological adaptations to capture patient preferences, and testing the pre-experimental design decisions of the DCE survey.

RESULTS

Of 8505 articles identified for abstract screening, 680 were included for full-text screening, 36 of which met the inclusion criteria. Practices to improve methodological robustness included pre-data collection materials to inform instruments, data collection methods specific for decision-making scenarios, purposeful selection of data analysis methods to address the research question, and participants' involvement in reducing the list of attributes. Examples of methodological adaptations for patients were noted.

CONCLUSIONS

DCEs have the potential to become a mixed-method approach in which the qualitative phase informs a reduced list of attributes for a survey, serves the predesign decisions of the experiment by testing trade-offs, overlapping, understandability, face, and content validity and provides explanations of the quantitative results. Establishing guidelines for using qualitative methods for DCE attribute development may help to broadly enhance the methodological robustness of DCEs.

Results From a Pilot Study of an Automated Directly Observed Therapy Intervention Using Artificial Intelligence With Conditional Economic Incentives Among Young Adults With HIV

BACKGROUND

Despite improvements in antiretroviral therapy (ART) availability, suboptimal adherence is common among youth with HIV (YWH) and can increase drug resistance and poor clinical outcomes. Our study examined an innovative mobile app-based intervention that used automated directly observed therapy (aDOT) using artificial intelligence, along with conditional economic incentives (CEIs) to improve ART adherence and enhance viral suppression among YWH.

SETTING

We conducted a pilot study of the aDOT-CEI intervention, informed by the operant framework of Key Principles in Contingency Management Implementation, to improve ART adherence among YWH (18-29) in California and Florida who had an unsuppressed HIV viral load.

METHODS

We recruited 28 virally unsuppressed YWH from AIDS Healthcare Foundation clinics, who used the aDOT platform for 3 months. Study outcomes included feasibility and acceptability, self-reported ART adherence, and HIV viral load.

RESULTS

Participants reported high satisfaction with the app (91%), and 82% said that it helped them take their medication. Comfort with the security and privacy of the app was moderate (55%), and 59% indicated the incentives helped improve daily adherence.

CONCLUSIONS

Acceptability and feasibility of the aDOT-CEI intervention were high with potential to improve viral suppression, although some a priori metrics were not met. Pilot results suggest refinements which may improve intervention outcomes, including increased incentive amounts, provision of additional information, and reassurance about app privacy and security. Additional research is recommended to test the efficacy of the aDOT-CEI intervention to improve viral suppression in a larger sample.

Identifying patient preferences for diabetes care: A protocol for implementing a discrete choice experiment in Samoa

In Samoa, adult Type 2 diabetes prevalence has increased within the past 30 years. Patient preferences for care are factors known to influence treatment adherence and are associated with reduced disease progression and severity. However, patient preferences for diabetes care, generally, are understudied, and other patient-centered factors such as willingness-to-pay (WTP) for diabetes treatment have never been explored in this setting. Discrete Choice Experiments (DCE) are useful tools to elicit preferences and WTP for healthcare. DCEs present patients with hypothetical scenarios composed of a series of multi-alternative choice profiles made up of attributes and levels. Patients choose a profile based on which attributes and levels may be preferable for them, thereby quantifying and identifying locally relevant patient-centered preferences. This paper presents the protocol for the design, piloting, and implementation of a DCE identifying patient preferences for diabetes care, in Samoa. Using an exploratory sequential mixed methods design, formative data from a literature review and semi-structured interviews with n = 20 Samoan adults living with Type 2 diabetes was used to design a Best-Best DCE instrument. Experimental design procedures were used to reduce the number of choice-sets and balance the instrument. Following pilot testing, the DCE is being administered to n = 450 Samoan adults living with diabetes, along with associated questionnaires, and anthropometrics. Subsequently, we will also be assessing longitudinally how preferences for care change over time. Data will be analyzed using progressive mixed Rank Order Logit models. The results will identify which diabetes care attributes are important to patients (p < 0.05), examine associations between participant characteristics and preference, illuminate the trade-offs participants are willing to make, and the probability of uptake, and WTP for specific attributes and levels. The results from this study will provide integral data useful for designing and adapting efficacious diabetes intervention and treatment approaches in this setting.

Experiences of conditional and unconditional cash transfers intended for improving health outcomes and health service use: a qualitative evidence synthesis

BACKGROUND

It is well known that poverty is associated with ill health and that ill health can result in direct and indirect costs that can perpetuate poverty. Social protection, which includes policies and programmes intended to prevent and reduce poverty in times of ill health, could be one way to break this vicious cycle. Social protection, particularly cash transfers, also has the potential to promote healthier behaviours, including healthcare seeking. Although social protection, particularly conditional and unconditional cash transfers, has been widely studied, it is not well known how recipients experience social protection interventions, and what unintended effects such interventions can cause.   OBJECTIVES: The aim of this review was to explore how conditional and unconditional cash transfer social protection interventions with a health outcome are experienced and perceived by their recipients.  SEARCH METHODS: We searched Epistemonikos, MEDLINE, CINAHL, Social Services Abstracts, Global Index Medicus, Scopus, AnthroSource and EconLit from the start of the database to 5 June 2020. We combined this with reference checking, citation searching, grey literature and contact with authors to identify additional studies. We reran all strategies in July 2022, and the new studies are awaiting classification.

SELECTION CRITERIA

We included primary studies, using qualitative methods or mixed-methods studies with qualitative research reporting on recipients' experiences of cash transfer interventions where health outcomes were evaluated. Recipients could be adult patients of healthcare services, the general adult population as recipients of cash targeted at themselves or directed at children. Studies could be evaluated on any mental or physical health condition or cash transfer mechanism. Studies could come from any country and be in any language. Two authors independently selected studies.  DATA COLLECTION AND ANALYSIS: We used a multi-step purposive sampling framework for selecting studies, starting with geographical representation, followed by health condition, and richness of data. Key data were extracted by the authors into Excel. Methodological limitations were assessed independently using the Critical Appraisal Skills Programme (CASP) criteria by two authors. Data were synthesised using meta-ethnography, and confidence in findings was assessed using the Confidence in the Evidence from Reviews of Qualitative research (GRADE-CERQual) approach.  MAIN RESULTS: We included 127 studies in the review and sampled 41 of these studies for our analysis. Thirty-two further studies were found after the updated search on 5 July 2022 and are awaiting classification. The sampled studies were from 24 different countries: 17 studies were from the African region, seven were from the region of the Americas, seven were from the European region, six were from the South-East Asian region, three from the Western Pacific region and one study was multiregional, covering both the African and the Eastern Mediterranean regions. These studies primarily explored the views and experiences of cash transfer recipients with different health conditions, such as infectious diseases, disabilities and long-term illnesses, sexual and reproductive health, and maternal and child health. Our GRADE-CERQual assessment indicated we had mainly moderate- and high-confidence findings. We found that recipients perceived the cash transfers as necessary and helpful for immediate needs and, in some cases, helpful for longer-term benefits. However, across conditional and unconditional programmes, recipients often felt that the amount given was too little in relation to their total needs. They also felt that the cash alone was not enough to change their behaviour and, to change behaviour, additional types of support would be required. The cash transfer was reported to have important effects on empowerment, autonomy and agency, but also in some settings, recipients experienced pressure from family or programme staff on cash usage. The cash transfer was reported to improve social cohesion and reduce intrahousehold tension. However, in settings where some received the cash and others did not, the lack of an equal approach caused tension, suspicion and conflict. Recipients also reported stigma in terms of cash transfer programme assessment processes and eligibility, as well as inappropriate eligibility processes. Across settings, recipients experienced barriers in accessing the cash transfer programme, and some refused or were hesitant to receive the cash. Some recipients found cash transfer programmes more acceptable when they agreed with the programme's goals and processes.   AUTHORS' CONCLUSIONS: Our findings highlight the impact of the sociocultural context on the functioning and interaction between the individual, family and cash transfer programmes. Even where the goals of a cash transfer programme are explicitly health-related, the outcomes may be far broader than health alone and may include, for example, reduced stigma, empowerment and increased agency of the individual. When measuring programme outcomes, therefore, these broader impacts could be considered for understanding the health and well-being benefits of cash transfers.

Use of Stated Preference Methods in HIV Treatment and Prevention Research in the United States: A Systematic Review

Stated preference (SP) methods are increasingly being applied to HIV-related research and continuously provide researchers with health utility scores of select healthcare products or services that populations consider important. Following PRISMA guidelines, we sought to understand how SP methods have been applied in HIV-related research. We conducted a systematic review to identify studies meeting the following criteria: SP method is clearly stated, conducted in the United States, was published between 01/01/2012 and 02/12/2022, and included adults aged 18 and over. Study design and SP method application were also examined. We identified six SP methods (e.g., Conjoint Analysis, Discrete Choice Experiment) across 18 studies, which were categorized into one of two groups: HIV prevention and HIV treatment-care. Categories of attributes used in SP methods largely focused on: administration, physical/health effects, financial, location, access, and external influences. SP methods are innovative tools capable of informing researchers on what populations consider most beneficial when deciding on treatment, care, or prevention options for HIV.

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.

Adolescent and young adult preferences for financial incentives to support adherence to antiretroviral therapy in Kenya: a mixed methods study

INTRODUCTION

To develop a patient-centred financial incentive delivery strategy to improve antiretroviral treatment adherence in adolescents and young adults (AYA) living with HIV in Kisumu, Kenya, we conducted a mixed methods study exploring preferences.

METHODS

A discrete choice experiment (DCE) and focus group discussion (FGD) were conducted simultaneously to identify preferences for five incentive delivery strategy features: value, eligibility, recipient, format and disbursement frequency. We used consecutive sampling to recruit AYA (14-24 years) living with HIV attending three health facilities in Kisumu, Kenya. We calculated mean preferences, willingness to trade, latent class membership and predictors of latent class membership. The FGD explored preferred incentive features, and, after deductive and inductive coding, qualitative findings were triangulated with DCE results.

RESULTS

Two hundred and seven AYA living with HIV (46% 14-17 years, 54% 18-24 years; 33% male sex, 89% viral load <50 copies/ml) were recruited to the study (28 October-16 November 2020). Two distinct preference phenotypes emerged from the DCE analysis (N = 199), 44.8% of the population fell into an "immediate reward" group, who wanted higher value cash or mobile money distributed at each clinic visit, and 55.2% fell into a "moderate spender" group, who were willing to accept lower value incentives in the form of cash or shopping vouchers, and accrued payments. The immediate reward group were willing to trade up to 200 Kenyan Shillings (KSH)-approximately 2 US dollars (USD)-of their 500 KSH (∼5 USD) incentive to get monthly as opposed to accrued yearly payments. The strongest predictor of latent class membership was age (RR 1.45; 95% CI: 1.08-1.95; p = 0.006). Qualitative data highlighted the unique needs of those attending boarding school and confirmed an overwhelming preference for cash incentives which appeared to provide the greatest versatility for use.

CONCLUSIONS

Providing small financial incentives as cash was well-aligned with AYA preferences in this setting. AYA should additionally be offered a choice of other incentive delivery features (such as mobile money, recipient and disbursement frequency) to optimally align with the specific needs of their age group and life stage.

How Do Psychosocial Interventions for Adolescents and Young People Living With HIV Improve Adherence and Viral Load? A Realist Review

PURPOSE

Psychosocial interventions have the potential to support adolescents and young people living with HIV (AYPLHIV) to achieve better HIV outcomes. However, more evidence is needed to understand which interventions are most effective, and the mechanisms driving how they work in practice.

METHODS

We used realist methodologies to generate statements based on evidence from intervention studies and linked evidence included in a systematic review of psychosocial interventions for AYPLHIV. Key data were extracted from available sources to generate cases, including context-mechanism-outcome pathways. Higher level themes were refined iteratively to create a mid-range theory of how these interventions may work.

RESULTS

From 26 resulting cases, 8 statements were crafted, grouped into 3 overarching categories, to describe how these interventions worked. Interventions were overall found to set off mechanisms to improve adherence when (1) responding to individual-level factors to support AYPLHIV (via incorporating agency and empowerment, personalized and/or contextualized approaches, and self-care skills); (2) tailoring delivery strategies to address specific needs (via diverse strategies, longer duration, and digital delivery); and (3) providing supportive resources (via peer and broader support, and structural support and integration into existing services).

DISCUSSION

A collection of diverse mechanisms may individually or collectively drive improved outcomes for AYPLHIV engaged in psychosocial interventions. Recommendations for integrating our findings into practice are discussed.

Conditional Economic Incentives for HIV Treatment Adherence: Aligning Adolescent Developmental Hallmarks with Behavioral Economic Theory to Improve HIV Treatment Adherence

Adolescent-tailored antiretroviral therapy (ART) adherence interventions take place within the context of unique developmental stage. Suboptimal ART adherence among adolescents living with HIV in South Africa underscores that interventions are urgently needed to improve adherence. We conducted semistructured in-depth interviews with 35 adolescents aged 10-19 years living with HIV. In addition, 14 clinicians and 35 caregivers were interviewed to provide a diverse perspective on barriers and facilitators of medication adherence for adolescents living with HIV (ALWH). Thematic coding was utilized for this analysis. Our main findings were organized by following a priori themes: (1) acceptability of conditional economic incentives (CEIs) as an adherence intervention strategy for adolescents, (2) predicted behavioral impacts, and the (3) durability of CEIs to ensure medication adherence for adolescents in the long term. Subthemes that emerged included CEIs as tool to overcome competing demands, increasing intrinsic motivation and orientation toward the future, and optimal timing of the intervention. Exposure to a CEI intervention during early adolescence (ages 10-13) may be a particularly helpful intervention as CEIs may have long-lasting effects given that habit-formation behavior is developed during early adolescence. There is little consensus on effect duration from the perspective of adolescents, clinicians, and caregivers. Future studies should continue to explore the impact of CEIs for long-term ART adherence.

Interventions to Improve Treatment Outcomes among Adolescents on Antiretroviral Therapy with Unsuppressed Viral Loads: A Systematic Review

Adolescents living with HIV (ALHIV) face unique developmental challenges that increase the risk of unsuppressed viral loads. Current reviews present a need for proven interventions to improve viral suppression among ALHIV on ART, who have a history of unsuppressed viral loads. This systematic review aims to synthesize and appraise evidence of the effectiveness of interventions to improve treatment outcomes among ALHIV with unsuppressed viral loads. Six bibliographic databases were searched for published studies and gray literature from 2010 to 2021. The risk of bias and certainty of evidence was assessed using the ROBINS-I tool, CASP checklists and GRADE. A total of 28 studies were eligible for full-text screening; and only three were included in the qualitative synthesis. In addition, two studies were included from website searches. Four types of interventions to improve viral suppression were identified, namely: intensive adherence counselling; community- and facility-based peer-led differentiated service delivery (DSD); family based economic empowerment; and conditional economic incentives and motivational interviewing. We strongly recommend peer-led community-based DSD interventions, intensive adherence counselling, and family-based economic empowerment as potential interventions to improve viral suppression among ALHIV.

Preferences for Conditional Economic Incentives to Improve Pre-exposure Prophylaxis Adherence: A Discrete Choice Experiment Among Male Sex Workers in Mexico

Pre-exposure prophylaxis (PrEP) is highly effective in preventing HIV but requires sustained adherence. Conditional economic incentives (CEIs) can improve medication-taking behaviors, yet preferences for programs that employ CEIs to increase PrEP use among male sex workers (MSWs) have not been investigated. We conducted a discrete choice experiment in Mexico City to elicit stated preferences for a CEI-based PrEP adherence program among MSWs. Respondents expressed their preferences for different program characteristics: incentive amount; incentive format; incentive type; and adherence-verification method. We used a random utility logit model to estimate the relative importance of each attribute and estimated willingness-to-pay. MSWs preferred a higher, fixed incentive, with PrEP adherence measured via hair sampling. MSWs were willing to forego up to 21% of their potential maximum CEI amount to ensure receipt of a fixed payment. MSWs are highly willing to accept a CEI-based intervention for PrEP adherence, if offered along with fixed payments.

Incorporating respondent-driven sampling into web-based discrete choice experiments: preferences for COVID-19 mitigation measures

To slow the spread of COVID-19, most countries implemented stay-at-home orders, social distancing, and other nonpharmaceutical mitigation strategies. To understand individual preferences for mitigation strategies, we piloted a web-based Respondent Driven Sampling (RDS) approach to recruit participants from four universities in three countries to complete a computer-based Discrete Choice Experiment (DCE). Use of these methods, in combination, can serve to increase the external validity of a study by enabling recruitment of populations underrepresented in sampling frames, thus allowing preference results to be more generalizable to targeted subpopulations. A total of 99 students or staff members were invited to complete the survey, of which 72% started the survey (n = 71). Sixty-three participants (89% of starters) completed all tasks in the DCE. A rank-ordered mixed logit model was used to estimate preferences for COVID-19 nonpharmaceutical mitigation strategies. The model estimates indicated that participants preferred mitigation strategies that resulted in lower COVID-19 risk (i.e. sheltering-in-place more days a week), financial compensation from the government, fewer health (mental and physical) problems, and fewer financial problems. The high response rate and survey engagement provide proof of concept that RDS and DCE can be implemented as web-based applications, with the potential for scale up to produce nationally-representative preference estimates.

"The Money, It's OK but It's not OK": Patients' and Providers' Perceptions of the Acceptability of Cash Incentives for HIV Treatment Initiation in Cape Town, South Africa

Incentive-based interventions are used to encourage HIV testing, linkage to HIV care, and antiretroviral therapy (ART) adherence. Studies assessing efficacy of cash incentives have raised questions about the perceived ethicality of and attitudes towards incentives. Here we explore patients' and health providers' perspectives of the acceptability of a conditional cash transfer for ART initiation after receiving a positive HIV test through community-based services in resource-poor communities in Cape Town, South Africa. Drawing on in-depth interviews with patients and health care workers (HCWs), we find that, despite the perception that cash incentives are effective in promoting ART initiation, significant ambivalence surrounds the acceptability of such incentives. The receipt of a financial incentive was highly moralized, and fraught with challenges. Increasing the acceptability of cash incentives through careful design and delivery of interventions is central to the potential of this type of intervention for improving outcomes along the HIV care continuum.

Behavioral Theories and Motivational Features Underlying eHealth Interventions for Adolescent Antiretroviral Adherence: Systematic Review

Background

eHealth systems provide new opportunities for the delivery of antiretroviral therapy (ART) adherence interventions for adolescents. They may be more effective if grounded in health behavior theories and behavior change techniques (BCTs). Prior reviews have examined the effectiveness, feasibility, and acceptability of these eHealth systems. However, studies have not systematically explored the use of health behavior theories and BCTs in the design of these applications.

Objective

The purpose of this review was to explore whether health behavior theories and BCTs were considered to ground designs of eHealth systems supporting adolescents’ (10-24 years) ART adherence. More specifically, we examined which specific theories and BCTs were applied, and how these BCTs were implemented as design features. Additionally, we investigated the quality and effect of eHealth systems.

Methods

A systematic search was performed on IEEE Xplore, ACM, ScienceDirect, PubMed, Scopus, and Web of Science databases from 2000 to 2020. Theory use and BCTs were coded using the Theory Coding Scheme and the Behavior Change Technique Taxonomy version 1 (BCTTv1), respectively. Design features were identified using the lenses of motivational design for mobile health (mHealth). The number of BCTs and design features for each eHealth system and their prevalence across all systems were assessed.

Results

This review identified 16 eHealth systems aiming to support ART adherence among adolescents. System types include SMS text message reminders (n=6), phone call reminders (n=3), combined SMS text message and phone call reminders (n=1), electronic adherence monitoring devices (n=3), smartphone apps (n=1), smartphone serious games (n=1), gamified smartphone apps (n=1), leveraging existing social media (n=2), web-based applications (n=1), videoconferencing (n=1), and desktop applications (n=1). Nine were grounded in theory, of which 3 used theories extensively. The impact of adolescent developmental changes on ART adherence was not made explicit. A total of 42 different BCTs and 24 motivational design features were used across systems. Ten systems reported positive effects on 1 or more outcomes; however, of these ten systems, only 3 reported exclusively positive effects on all the outcomes they measured. As much as 6 out of 16 reported purely no effect in all the outcomes measured.

Conclusions

Basic applications (SMS text messaging and phone calls) were most frequent, although more advanced systems such as mobile apps and games are also emerging. This review indicated gaps in the use of theory and BCTs, and particularly the impact of developmental changes on ART adherence was not adequately considered. Together with adopting a developmental orientation, future eHealth systems should effectively leverage health theories and consider developing more advanced systems that open the door to using BCTs more comprehensively. Overall, the impact of eHealth systems on adolescent ART adherence and its mediators is promising, but conclusive evidence on effect still needs to be provided.

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.