Valuing Preferences for the Process and Outcomes of Clinical Genetics Services: A Pilot Study

Reporting Quality of Marginal Rates of Substitution in Discrete Choice Experiments That Elicit Patient Preferences

BACKGROUND

Discrete choice experiments (DCEs) are commonly used to elicit patient preferences as marginal rates of substitution (MRSs) between treatment or health service attributes. Because these studies are increasing in importance, it is vital that uncertainty around MRS estimates is reported.

OBJECTIVE

To review recently published DCE studies that elicit patient preferences in relation to MRS reporting and to explore the accuracy of using other reported information to estimate the uncertainty of the MRSs.

METHODS

A systematic literature review of DCEs conducted with patients between 2014 and July 2019 was performed. The number of studies reporting coefficients, MRSs, standard errors (SEs), and confidence intervals was recorded. If all information was reported, studies were included in an analysis to determine the impact of estimating the SEs of MRSs using coefficients and assuming zero covariance, to determine the impact of this assumption.

RESULTS

Two hundred and thirty-two patient DCEs were identified in the review; 34.1% (n = 79) reported 1 or more MRS and, of these, only 62.0% (n = 49) provided an estimate of the uncertainty. Of these studies, 16 contained enough information for inclusion in the analysis, providing 116 datapoints. Actual SEs were smaller than estimated SEs in 75.0% of cases (n = 87), and estimated SEs were within 25% of the actual SE in 59.5% of cases (n = 69).

CONCLUSION

Uncertainty of MRS estimates is unreported in a substantial proportion of recently published DCE studies. Estimating the SE of a MRS by solely using the SEs of the utility coefficients is likely to lead to biased estimates of the precision of patient trade-offs.

The Fold-in, Fold-out Design for DCE Choice Tasks: Application to Burden of Disease

Background In discrete-choice experiments (DCEs), choice alternatives are described by attributes. The importance of each attribute can be quantified by analyzing respondents’ choices. Estimates are valid only if alternatives are defined comprehensively, but choice tasks can become too difficult for respondents if too many attributes are included. Several solutions for this dilemma have been proposed, but these have practical or theoretical drawbacks and cannot be applied in all settings. The objective of the current article is to demonstrate an alternative solution, the fold-in, fold-out approach (FiFo). We use a motivating example, the ABC Index for burden of disease in chronic obstructive pulmonary disease (COPD). Methods Under FiFo, all attributes are part of all choice sets, but they are grouped into domains. These are either folded in (all attributes have the same level) or folded out (levels may differ). FiFo was applied to the valuation of the ABC Index, which included 15 attributes. The data were analyzed in Bayesian mixed logit regression, with additional parameters to account for increased complexity in folded-out questionnaires and potential differences in weight due to the folding status of domains. As a comparison, a model without the additional parameters was estimated. Results Folding out domains led to increased choice complexity for respondents. It also gave domains more weight than when it was folded in. The more complex regression model had a better fit to the data than the simpler model. Not accounting for choice complexity in the models resulted in a substantially different ABC Index. Conclusion Using a combination of folded-in and folded-out attributes is a feasible approach for conducting DCEs with many attributes.

Understanding Midwives' Preferences for Providing Information About Newborn Bloodspot Screening

Background: Understanding preferences for information provision in the context of health care service provision is challenging because of the number of potential attributes that may influence preferences. This study aimed to identify midwives’ preferences for the process and outcomes of information provision in an expanded national newborn bloodspot screening program. Design: A sample of practicing midwives completed a hybrid-stated preference survey including a conjoint analysis (CA) and discrete choice experiment to quantify preferences for the types of, and way in which, information should be provided in a newborn bloodspot screening program. Six conjoint analysis questions captured the impact of different types of information on parents’ ability to make a decision, and 10 discrete choice experiment questions identified preferences for four process attributes (including parents’ ability to make a decision). Results: Midwives employed by the UK National Health Service (n = 134) completed the survey. All types of information content were perceived to improve parents’ ability to make a decision except for the possibility of false-positive results. Late pregnancy was seen to be the best time to provide information, followed by day 3 postbirth. Information before 20 weeks of pregnancy was viewed as reducing parents’ ability to make a decision. Midwives preferred information to be provided by an individual discussion and did not think parents should receive information on the Internet. Conclusion: A hybrid stated preference survey design identified that a wide variety of information should be provided to maximize parents’ ability to make a decision ideally provided late in pregnancy or on day 3 postbirth.

Cost-effectiveness of Genome and Exome Sequencing in Children Diagnosed with Autism Spectrum Disorder

BACKGROUND

Genome (GS) and exome sequencing (ES) could potentially identify pathogenic variants with greater sensitivity than chromosomal microarray (CMA) in autism spectrum disorder (ASD) but are costlier and result interpretation can be uncertain. Study objective was to compare the costs and outcomes of four genetic testing strategies in children with ASD.

METHODS

A microsimulation model estimated the outcomes and costs (in societal and public payer perspectives in Ontario, Canada) of four genetic testing strategies: CMA for all, CMA for all followed by ES for those with negative CMA and syndromic features (CMA+ES), ES or GS for all.

RESULTS

Compared to CMA, the incremental cost-effectiveness ratio (ICER) per additional child identified with rare pathogenic variants within 18 months of ASD diagnosis was $CAN5997.8 for CMA+ES, $CAN13,504.2 for ES and $CAN10,784.5 for GS in the societal perspective. ICERs were sensitive to changes in ES or GS diagnostic yields, wait times for test results or pre-test genetic counselling, but were robust to changes in the ES or GS costs.

CONCLUSION

Strategic integration of ES into ASD care could be a cost-effective strategy. Long wait times for genetic services and uncertain utility, both clinical and personal, of sequencing results could limit broader clinical implementation.

Provision of information about newborn screening antenatally: a sequential exploratory mixed-methods project

BACKGROUND

Participation in the UK Newborn Bloodspot Screening Programme (NBSP) requires parental consent but concerns exist about whether or not this happens in practice and the best methods and timing to obtain consent at reasonable cost.

OBJECTIVES

To collate all possible modes of prescreening communication and consent for newborn (neonatal) screening (NBS); examine midwives', screening professionals' and users' views about the feasibility, efficiency and impact on understanding of each; measure midwives' and parents' preferences for information provision; and identify key drivers of cost-effectiveness for alternative modes of information provision.

DESIGN

Six study designs were used: (1) realist review - to generate alternative communication and consent models; (2) qualitative interviews with parents and health professionals - to examine the implications of current practice for understanding and views on alternative models; (3) survey and observation of midwives - to establish current costs; (4) stated preference surveys with midwives, parents and potential future parents - to establish preferences for information provision; (5) economic analysis - to identify cost-effectiveness drivers of alternative models; and (6) stakeholder validation focus groups and interviews - to examine the acceptability, views and broader impact of alternative communication and consent models.

SETTING

Providers and users of NBS in England.

PARTICIPANTS

Study 2: 45 parents and 37 health professionals; study 3: 22 midwives and eight observations; study 4: 705 adults aged 18-45 years and 134 midwives; and study 6: 12 health-care professionals and five parents.

RESULTS

The realist review identified low parental knowledge and evidence of coercive consent practices. Interview, focus group and stated preference data suggested a preference for full information, with some valuing this more than choice. Health professionals preferred informed choice models but parents and health professionals queried whether or not current consent was fully informed. Barriers to using leaflets effectively were highlighted. All studies indicated that a 'personalised' approach to NBS communication, allowing parents to select the mode and level of information suited to their learning needs, could have added value. A personalised approach should rely on midwife communication and should occur in the third trimester. Overall awareness was identified as requiring improvement. Starting NBS communication by alerting parents that they have a choice to make and telling them that samples could be stored are both likely to enhance engagement. The methods of information provision and maternal anxiety causing additional visits to health-care professionals were the drivers of relative cost-effectiveness. Lack of data to populate an economic analysis, confirmed by value of information analysis, indicated a need for further research.

LIMITATIONS

There are some limitations with regard to the range of participants used in studies 2 and 3 and so caution should be exercised when interpreting some of the results.

CONCLUSIONS

This project highlighted the importance of focusing on information receipt and identified key communication barriers. Health professionals strongly preferred informed consent, which parents endorsed if they were made aware of sample storage. Uniform models of information provision were perceived as ineffective. A choice of information provision was supported by health professionals and parents, which both enhances cost-effectiveness and improves engagement, understanding and the validity of consent. Remaining uncertainties suggest that more research is needed before new communication modes are introduced into practice. Future research should measure the impact of the suggested practice changes (informing in third trimester, information toolkits, changed role of midwife).

TRIAL REGISTRATION

Current Controlled Trials ISRCTN70227207.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 55. See the NIHR Journals Library website for further project information.

Rapid Identification of Pathogenic Variants in Two Cases of Charcot-Marie-Tooth Disease by Gene-Panel Sequencing

Charcot-Marie-Tooth disease (CMT) is a common inherited peripheral neuropathy affecting up to 1 in 1214 of the general population with more than 60 nuclear genes implicated in its pathogenesis. Traditional molecular diagnostic pathways based on relative prevalence and clinical phenotyping are limited by long turnaround time, population-specific prevalence of causative variants and inability to assess multiple co-existing variants. In this study, a CMT gene panel comprising 27 genes was used to uncover the pathogenic mutations in two index patients. The first patient is a 15-year-old boy, born of consanguineous parents, who has had frequent trips and falls since infancy, and was later found to have inverted champagne bottle appearance of bilateral legs and foot drop. His elder sister is similarly affected. The second patient is a 37-year-old woman referred for pre-pregnancy genetic diagnosis. During early adulthood, she developed progressive lower limb weakness, difficulties in tip-toe walking and thinning of calf muscles. Both patients are clinically compatible with CMT, have undergone multiple genetic testings and have not previously received a definitive genetic diagnosis. Patients 1 and 2 were found to have pathogenic homozygous HSPB1:NM_001540:c.250G>A (p.G84R) variant and heterozygous GDAP1:NM_018972:c.358C>T (p.R120W) variant, respectively. Advantages and limitations of the current approach are discussed.

Eliciting Preferences for Information Provision in Newborn Bloodspot Screening Programs

BACKGROUND

The national newborn bloodspot screening programs (NBSPs) are continually expanding to screen for more conditions.

OBJECTIVES

To quantify parents' preferences for information and the way in which this is provided in example NBSPs.

METHODS

A hybrid choice experiment, combining a conjoint analysis and a discrete choice experiment, was designed. A sample of current and future parents between the ages of 18 and 45 years was identified via an Internet panel. Respondents completed one of two survey versions (9 conditions and 20 conditions) comprising a validated measure of attitudes toward involvement in decision making, 6 CA questions (11 information attributes), 10 DCE questions (4 attributes: 3 process and the ability to make an informed decision), and demographic questions.

RESULTS

Of the 702 respondents who completed the survey, 58% were women, 48% were between 25 and 34 years old, and 48% were current parents. All types of information were identified to statistically significantly improve parents' ability to make a decision. Participants preferred taking an "active" role in decision making. Respondents to the 9-condition survey preferred information before 20 weeks (willingness to pay [WTP] £11.88; CI £5.56 to £19.53) and the 20-condition group after 20 weeks (WTP £15.91; CI £10.64 to £21.63). All respondents disliked receiving information 3 days after birth, with the 20-condition group also being averse to receiving it on day 5 (WTP -£11.20; CI -£18.40 to 5.72). Respondents in both groups preferred to receive their information in an individual discussion.

CONCLUSIONS

This study suggests that parents' preferences for receiving NBS information differ from how this information is given in current UK practice.

Statistical Methods for the Analysis of Discrete Choice Experiments: A Report of the ISPOR Conjoint Analysis Good Research Practices Task Force

Conjoint analysis is a stated-preference survey method that can be used to elicit responses that reveal preferences, priorities, and the relative importance of individual features associated with health care interventions or services. Conjoint analysis methods, particularly discrete choice experiments (DCEs), have been increasingly used to quantify preferences of patients, caregivers, physicians, and other stakeholders. Recent consensus-based guidance on good research practices, including two recent task force reports from the International Society for Pharmacoeconomics and Outcomes Research, has aided in improving the quality of conjoint analyses and DCEs in outcomes research. Nevertheless, uncertainty regarding good research practices for the statistical analysis of data from DCEs persists. There are multiple methods for analyzing DCE data. Understanding the characteristics and appropriate use of different analysis methods is critical to conducting a well-designed DCE study. This report will assist researchers in evaluating and selecting among alternative approaches to conducting statistical analysis of DCE data. We first present a simplistic DCE example and a simple method for using the resulting data. We then present a pedagogical example of a DCE and one of the most common approaches to analyzing data from such a question format-conditional logit. We then describe some common alternative methods for analyzing these data and the strengths and weaknesses of each alternative. We present the ESTIMATE checklist, which includes a list of questions to consider when justifying the choice of analysis method, describing the analysis, and interpreting the results.