Valuation of Treatments for Rare Diseases: A Systematic Literature Review of Societal Preference Studies

INTRODUCTION

We sought to synthesize published empirical studies that elicited and characterized societal valuations of orphan drugs and the attributes that may drive different valuations for orphan drugs versus other treatments.

METHODS

We conducted a systematic literature review (SLR) in MEDLINE and EMBASE databases up to November 2, 2020. Search terms covered societal preferences and attributes of orphan drugs (e.g., disease prevalence, severity, burden, unmet needs, and benefits).

RESULTS

We identified 38 eligible publications: 33 societal preference studies and 5 reviews discussing societal valuations and attributes of orphan drugs. Most publications suggested that a majority of respondents favored allocating funds to more prevalent diseases. However, trade-off studies and discrete-choice experiments found that survey participants chose to allocate resources to orphan drugs even when the cost per unit of health benefit was greater than for therapies for more prevalent diseases. Overall, 19 of 27 studies assessing severity in treatment valuation revealed that respondents prioritized patients with severe diseases over those with milder ones for equal health benefits. Members of the general public tended to prefer treatments for diseases with no alternative or when existing alternatives had limited efficacy over diseases with clear therapeutic alternatives. There was evidence that individuals preferred sharing resources, so no patient was left without treatment.

CONCLUSIONS

Our SLR indicates the general public typically attaches greater value to orphan drugs than to other treatments for common diseases. This is not because of rarity per se, but primarily because of disease severity and lack of therapeutic alternatives typically associated with rare diseases.

Measuring the acceptability of EQ-5D-3L health states for different ages: a new adaptive survey methodology

BACKGROUND

Acceptable health and sufficientarianism are emerging concepts in health resource allocation. We defined acceptability as the proportion of the general population who consider a health state acceptable for a given age. Previous studies surveyed the acceptability of health problems separately per EQ-5D-3L domain, while the acceptability of health states with co-occurring problems was barely explored.

OBJECTIVE

To quantify the acceptability of 243 EQ-5D-3L health states for six ages from 30 to 80 years: 1458 health state-age combinations (HAcs), denoted as the acceptability set of EQ-5D-3L.

METHODS

In 2019, an online representative survey was conducted in the Hungarian general population. We developed a novel adaptive survey algorithm and a matching statistical measurement model. The acceptability of problems was evaluated separately per EQ-5D-3L domain, followed by joint evaluation of up to 15 HAcs. The selection of HAcs depended on respondents' previous responses. We used an empirical Bayes measurement model to estimate the full acceptability set.

RESULTS

1375 respondents (female: 50.7%) were included with mean (SD) age of 46.7 (14.6) years. We demonstrated that single problems that were acceptable separately for a given age were less acceptable when co-occurring jointly (p < 0.001). For 30 years of age, EQ-5D-3L health states of '11112' (11.9%) and '33333' (1%), while for 80 years of age '21111' (93.3%) and '33333' (7.4%) had highest and lowest acceptability (% of population), respectively.

CONCLUSION

The acceptability set of EQ-5D-3L quantifies societal preferences concerning age and disease severity. Its measurement profiles and potential role in health resource allocation needs further exploration.

Are some QALYs more equal than others?

Including societal preferences in allocation decisions is an important challenge for the health care sector. Here, we present results of a phased discrete choice experiment investigating the impact of various attributes on respondents' preferences for distribution of health and health care. In addition to the renowned equity principles severity of illness (operationalized as initial health) and fair innings (operationalized as age), some characteristics of beneficiaries (culpability and having dependents) and the disease (rarity) were included in the choice experiment. We used a nested logit model to analyse the data. We found that all selected attributes significantly influenced respondents' choices. The phased inclusion showed that additional attributes affected respondents' preferences for previously-included attributes and reduced unobserved variance. Although not all these attributes may be considered relevant for decision making from a normative perspective, including them in choice experiments contributes to our understanding of societal preferences for each single attribute.

Prioritizing treatment of rare diseases: a survey of preferences of Norwegian doctors

Understanding doctors' preferences for prioritizing treatment of rare diseases can provide an important context for policy makers who must decide whether to exempt rare disease treatments, which are often quite expensive, from standard cost-effectiveness criteria. We surveyed a random sample of 551 Norwegian doctors in November 2011 and compared results to a similar survey of the Norwegian population. Respondents chose whether to prioritize treatment of patients with rare versus common diseases and then decided how to allocate funds between the two groups for each of two scenarios: (1) equal costs per person and (2) higher costs for the rare disease. Respondents were randomized to treatment costs for the rare disease in the second scenario that were either 8 or 25 times higher than treating the common disease. Except for different prevalence, the diseases were described identically. Doctors displayed no general preference for prioritizing treatment of rare diseases, but a large number favored the principle of reserving a small share of funds for rare disease patients. Doctors' responses differed significantly from those of the general population when the rare disease was more costly to treat. A larger share of doctors prioritized the common disease group for treatment while a smaller share expressed indifference. When dividing funds between the two patient groups, doctors allocated a smaller share of funds to the rare disease. Doctors were much less likely than the general population to divide funds equally between the groups. This study indicates that there is little support among Norwegian doctors for prioritizing the treatment of rare diseases.