Quantifying the Altruism Value for a Rare Pediatric Disease: Duchenne Muscular Dystrophy

ABSTRACT

Objectives: To quantify the magnitude of altruism value as applied to a hypothetical new treatment for a rare, severe pediatric disease: Duchenne muscular dystrophy (DMD).

Study Design: Prospective survey of individuals not planning to have children in the future.

Methods: A survey was administered to US adults (aged ≥ 21 years) not intending to have a child in the future to elicit willingness to pay (WTP) for government insurance coverage for a new hypothetical DMD treatment that improves mortality and morbidity relative to the current standard of care. A multiple random staircase design was used to identify an indifference point between status quo government insurance coverage and coverage with additional cost in taxes that would cover the treatment if unrelated individuals had a child with DMD. Altruism value was calculated as respondents’ mean WTP.

Results: Among 215 respondents, 54.9% (n = 118) were aged 25 to 44 years and 80.0% (n = 172) were women. Mean WTP for insurance coverage of the hypothetical DMD treatment for others was $80.01 (95% CI, $41.64-$118.37) annually, or $6.67 monthly, after adjustment to account for disease probability overestimation. The adjusted altruism value was higher than the ex ante per-person value using traditional cost-effectiveness approaches ($45.30/year). Without adjusting, individuals were willing to pay $799.11 annually ($66.59 monthly).

Conclusions: Despite no possibility of accruing health benefits directly for themselves or their children, individuals had a high WTP for government insurance coverage of a novel treatment for this rare, severe pediatric disease.

Am J Manag Care. 2025;31(5):In Press

Takeaway Points

The degree to which novel value elements such as altruism value impact estimated treatment value for rare, severe genetic diseases such as Duchenne muscular dystrophy (DMD) is unclear. This study estimated the altruism value of a novel DMD treatment from a survey of individuals not planning to have children.

• Individuals placed a high level of altruism value (approximately $80 annually) on having novel DMD treatments available for future children who may or may not have DMD.
• The public demonstrated a high willingness to pay for rare, severe diseases that impact children.

Orphan drug policies that incentivize development of drugs to treat rare diseases are widespread across the developed world. For example, one study found that 27 of 35 countries evaluated had orphan drug legislation in place,¹ such as the Orphan Drug Act in the US.² Additionally, some policy makers and payers have special payment and reimbursement criteria for orphan drugs, although there is wide variability across countries.¹ These special considerations may reflect society’s willingness to pay (WTP) for orphan drugs, even if those drugs do not meet standard cost-effectiveness WTP thresholds.³

One rationale for a higher WTP for orphan drugs is altruism. Altruism value occurs when individuals place a value on helping others even if they themselves—or their direct family members—do not benefit from improved treatment options. Some studies have quantified the altruism values for the treatment of widespread diseases (eg, COVID-19,⁴ Alzheimer disease⁵). However, there is limited literature that empirically quantifies the altruism value for rare, severe pediatric diseases.⁶

Duchenne muscular dystrophy (DMD) is a rare genetic pediatric disease. Patients with DMD follow a progressive, severe disease course with loss of ambulation in the teen years, followed by upper body, respiratory, and cardiac weakness and eventual death typically in their 20s.^7-10

This study aimed to quantify the value of altruism for a hypothetical novel treatment for DMD and compare the altruism value with the value measured using traditional cost-effectiveness approaches.

METHODS

Overview of Study Design

This study used a web-based, cross-sectional survey to estimate the altruism value of a novel treatment for DMD that improved survival and slowed disease progression. To ensure that respondents themselves would have no direct benefit from the treatment of this pediatric genetic condition, respondents were limited to those who did not intend to have children (or did not intend to have more children among those already with children). Altruism value was estimated based on respondent’s WTP an additional monthly tax for coverage of a novel DMD treatment, which would be given to children outside their immediate family.

Study Population

The survey was administered to members of the general public who were 21 years and older, were US residents, and completed an informed consent form. Participants who indicated that they do not intend to have a child in the future (or to have more children in the future if they already had children) were included in the analysis. The cohort in this study was drawn from the global community panel (Sago).⁷

Survey Design

To measure the amount that a respondent was willing to pay to have a novel DMD treatment available for other children, respondents were presented with 6 questions involving binary choice pairs of different insurance plans. Respondents were required to repeatedly choose between 2 government insurance benefit designs that were identical in terms of pharmaceutical out-of-pocket costs and cost sharing for provider (eg, physician, hospital) services but differed in terms of the additional tax payments individuals would have to make. Insurance plan 1 required individuals to contribute no additional tax payments ($0) but covered only a conventional treatment for patients with DMD in the US; insurance plan 2 covered a novel treatment that improved morbidity and mortality for patients with DMD over and above a conventional treatment, but respondents would have to pay additional taxes each month (Figure 1). The respondent was informed that if they chose the conventional treatment option (insurance plan 1), the newer DMD treatment would not be available to other children in the US, nor could these children receive the newer DMD treatment outside the health insurance system. Conversely, if the respondent chose the alternative plan that covered the newer DMD treatment (insurance plan 2), patients with DMD would receive the newer, more effective treatment with no additional out-of-pocket cost. Coverage of all other treatments was the same in both plans.

This study used a multiple random staircase approach^8-10 to reduce the probability of protest responses and manipulation bias. Individuals were first presented with a choice of a standard health plan at no additional cost (insurance plan 1) or an additional $30 per month for the health plan that would cover the novel treatment for DMD (insurance plan 2). The $30 figure was selected as an amount approximately two-thirds of the ex ante treatment value (see eAppendix Table 1 and Shafrin et al¹¹ for derivation [eAppendix available at ajmc.com]). If the individual selected the generous health plan (insurance plan 2), the question was repeated with a higher monthly tax amount for the generous plan; conversely, if the individual selected the standard health plan (insurance plan 1), the question was repeated with a lower tax amount for the generous health plan. This process was repeated 6 times, and the monthly WTP for insurance plan 2 was constrained between $0 and $90 (selected based on pilot testing of the survey) (see eAppendix for more details).

Survey Administration

To verify intelligibility, we conducted 3 pilot tests between June and July 2022. The survey was adjusted to be conducted only on a desktop, laptop, or tablet rather than a mobile phone due to difficulty in viewing the survey graphics on mobile devices. Respondents were remunerated for completing the survey. All individuals were required to complete an informed consent form prior to initiating the survey. The study received institutional review board (IRB) exemption from Advarra IRB.

Statistical Analysis

WTP was estimated based on their responses to the survey in terms of an incremental additional monthly tax to be paid for government coverage of a novel DMD treatment. The self-reported monthly WTP was converted to an annual payment to determine the per-person altruism value of a novel DMD treatment.

To account for the potential for respondents to overestimate the disease probability for rare conditions, estimates were adjusted using decision weights. The estimated disease incidence of 1 in 10,000 births was used in constructing the treatment valuation.¹² Cumulative prospect theory decision weights, using the functionderived by Takemura and Murakami¹³ with the value of γ = 0.75, were used to adjust the altruism value by incorporating that respondents could overestimate the risk of the low-probability event that other families’ children would have DMD. The value of γ was chosen by using the approximate midpoint of the range found by Stott in a review paper¹⁴ on probability weighting between 0.5 and 0.96 and is more conservative than a γ of 0.8 used by Takemura and Murakami.¹³

Sensitivity Analysis

To evaluate the robustness of the results, we conducted 3 sensitivity analyses. First, respondent characteristics (age, gender, annual income, employment status, and education) were explored to determine whether they affected the altruism value estimate. Second, the survey population was reweighted to match the US national population by demographics and income. Third, estimates were reported not accounting for prospect theory decision weights.

RESULTS

Study Population

Of the 422 adult respondents, 215 did not intend to have children in the future and were included in the altruism value analysis. Approximately 54.9% (n = 118) of these respondents were aged 25 to 44 years, 80.0% (n = 172) were women, 17.7% (n = 38) were men, and 2.3% (n = 5) identified as nonbinary. Further, 55.3% (n = 119) of respondents reported an annual income between $10,000 and $74,999 (eAppendix Table 2).

Willingness to Pay

A majority of individuals were willing to pay nontrivial amounts of taxes to have the government provide insurance coverage for a hypothetical novel DMD treatment. The distribution of stated (unadjusted) WTP for each respondent was bimodal around the minimum and maximum values possible in the survey, with 58.1% (n = 125) of individuals having an altruism value between $80 and $90 per month and 14.0% (n = 30) of individuals willing to pay less than $10 per month (Figure 2). After adjusting using decision weights, respondents had a mean WTP of $80.01 (95% CI, $41.64-$118.37) per year ($6.67 monthly) in additional taxes for the government to provide the novel DMD treatment to others.

Sensitivity Analyses

The robustness of the altruism value results was largely consistent across the sensitivity analyses performed. First, although age, gender, employment status, and education level did not result in differences in altruism value estimates, respondent income did have an impact on the calculated altruism value (eAppendix Table 3). Second, altruism valuations were largely insensitive when the survey population was reweighted to match the US national population by age and gender ($78.53 annually, $6.54 monthly) and by age and income ($82.38 annually, $6.87 monthly) (eAppendix Table 4). Weights for both scenarios are presented in eAppendix Table 5 and eAppendix Table 6. Third, when decision weights were removed from the calculation (ie, the stated WTP in the survey), the altruism value was much larger at $799.11 per year ($66.59 monthly).

DISCUSSION

This study found a high level of altruism value—a decision weight–adjusted WTP near $80 in additional taxes per person per year—for providing access to a novel DMD treatment. This study’s annual altruism value estimates are similar to those found by Carlsson et al in a survey of altruism value for patients in Sweden with hemophilia (€65 [study conducted in 2000]).⁶ Whereas the Carlsson study utilized a single annual income deduction range from less than €1 to €130 to elicit altruistic WTP, this study is based on a representative US population and explored additional monthly tax payments to elicit per-person annual altruism values. This study’s large altruism value shows that individuals are willing to contribute substantially for DMD coverage, despite no direct benefit for themselves or their immediate family.¹⁵ These findings add to the body of the existing literature indicating that individuals are willing to prioritize severe pediatric diseases and support the funding of their treatments.¹⁶

Limitations

This study has several limitations. First, this was a stated preference survey and respondents did not actually have to pay money in increased taxes; stated preferences may differ from real-world actions. Second, because this was a voluntary survey conducted online, it could have been biased toward people who are more educated and biased away from older individuals or those who are less comfortable with computers. The sample size was modest, and extrapolation to the entire US population is speculative. However, in the sensitivity analysis, reweighting by age and income did not impact the results materially. Third, prospect theory indicates that respondents may have problems comprehending very small probabilities.^17,18 The results were highly sensitive to the decision weights used; decision-weighted WTP results ($66.59/month) were approximately 10 times as large as the baseline adjusted results ($6.67/month). Fourth, respondent WTP could vary depending on the survey’s initial reference value; nevertheless, most respondents had much higher WTP than the initial reference value—and many respondents’ values were top coded—so the initial reference point value was unlikely to have impacted this study’s qualitative and quantitative conclusions. Fifth, this study—as is the case for any stated preference WTP study—may be susceptible to a variety of biases including hypothetical bias,^19,20 anchoring bias,²¹ information bias,²² opportunity cost bias,²⁰ and payment vehicle bias,²³ among others.

CONCLUSIONS

This study found that the altruism value for a novel, hypothetical DMD treatment was high, with a decision weight–adjusted WTP of $80.01 per year (unadjusted, $799.11 per year) in additional taxes to cover the treatment. The respondents demonstrated a high WTP for a treatment for this rare, severe disease that impacts children, despite receiving no benefit directly for themselves or their families. This underscores the immense compassion that society has for children with DMD and emphasizes the critical role of societal support and empathy in advancing health care management and improving the lives of those living with DMD.

Acknowledgments

Sensitivity analyses and manuscript writing for this study were provided by Khounish Sharma, BA, BS. Rucha Kulkarni, MS, assisted with the design of the survey.

Author Affiliations: Center for Healthcare Economics and Policy, FTI Consulting, Inc, Los Angeles, CA (JS), and Washington, DC (ST); Economics and Reimbursement Access (ACK), Patient-Centered Outcomes (IA), and Global Market Access (IA, LES), Sarepta Therapeutics, Inc, Cambridge, MA; Sol Price School of Public Policy, University of Southern California (JAR), Los Angeles, CA.

Source of Funding: This study was funded by Sarepta Therapeutics. Employees of the funder were involved in the design of the study, the review or approval of the manuscript, and the decision to submit the manuscript for publication.

Author Disclosures: Dr Shafrin is employed by FTI Consulting and has received honoraria as a guest lecturer at the University of Southern California; FTI Consulting received payment for involvement in the preparation of this manuscript from Sarepta Therapeutics. Mr Thahir is employed by FTI Consulting. Ms Klimchak, Ms Audhya, and Ms Sedita are employed by and own stock in Sarepta Therapeutics, which develops therapies for Duchenne muscular dystrophy. Dr Romley reports no relationship or financial interest with any entity that would pose a conflict of interest with the subject matter of this article.

Authorship Information: Concept and design (JS, ST, ACK, IA, LES, JAR); acquisition of data (JS, ST); analysis and interpretation of data (JS, ST, JAR); drafting of the manuscript (JS, ST); critical revision of the manuscript for important intellectual content (JS, ACK, IA, LES, JAR); statistical analysis (JS, ST); obtaining funding (ACK, IA, LES); administrative, technical, or logistic support (ST); and supervision (JS).

Address Correspondence to: Jason Shafrin, PhD, Center for Healthcare Economics and Policy, FTI Consulting, 350 S Grand Ave, Ste 3000, Los Angeles, CA 90071. Email: jason.shafrin@fticonsulting.com.

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