Quality-Adjusted Life Years in Erythropoietic Protoporphyria and Other Rare Diseases: A Patient-Initiated EQ-5D Feasibility Study

Erythropoietic protoporphyrias: updates and advances

Protoporphyrias are caused by pathogenic variants in genes encoding enzymes involved in heme biosynthesis. They induce the accumulation of a hydrophobic phototoxic compound, protoporphyrin (PPIX), in red blood cells (RBCs). PPIX is responsible for painful cutaneous photosensitivity, which severely impairs quality of life. Hepatic elimination of PPIX increases the risk of cholestatic liver disease, requiring lifelong monitoring. Treatment options are scarce and mainly limited to supportive care such as protection from visible light. Here, we review the pathophysiology of protoporphyrias, their diagnosis, and current recommendations for medical care. We discuss new therapeutic strategies, some of which are currently undergoing clinical trials and are likely to radically alter the severity of the disease in the years to come.

Comparison of the measurement properties and consistency between the EQ-5D-3L and EQ-5D-Y-3L in adolescents aged 15-17 in China

OBJECTIVE

To evaluate and compare the measurement properties and consistency between the Chinese versions of EQ-5D-3L and EQ-5D-Y-3L among Chinese adolescent populations aged 15-17 years.

METHODS

Chinese adolescents aged 15-17 studying in high school were recruited through online survey. Social-demographic characteristics and self-reported EQ-5D-3L and EQ-5D-Y-3L responses were collected in the survey. The consistency of responses between the two measures was assessed using redistribution property, and the consistency of utility values was assessed by intraclass correlation coefficients (ICC). Convergent validity and known-group validity were examined using Spearman's rank correlation, F-test and effect sizes, respectively. Sensitivity was compared using relative efficiency (RE).

RESULTS

762 respondents (48.8% male; age 15-17 years;) were recruited. The EQ-5D-3L showed a more severe ceiling effect than EQ-5D-Y-3L (78.2% vs. 66.0%). Respondents reported higher proportions of having problems in four dimensions using the EQ-5D-Y-3L than using the EQ-5D-3L. The consistency of corresponding dimensions between the two measures was relatively good, while non-negligible proportions of inconsistency were observed in "pain/discomfort" (11.4%) and "anxiety/depression" (15.7%) dimensions. The ICC of the utility values between the EQ-5D-3L and EQ-5D-Y-3L was 0.852 (p < 0.001). The Spearman's rank correlation (range: 0.385-0.620) indicated an acceptable convergent validity between the correlative dimensions of the EQ-5D-3L and EQ-5D-Y-3L. The EQ-5D-Y-3L had a higher efficiency than the EQ-5D-3L at detecting differences across EQ VAS subgroups (ES = 1.793 for EQ-5D-3L, ES = 1.920 for EQ-5D-Y-3L). Mixed results were observed in sensitivity.

CONCLUSIONS

Both the EQ-5D-3L and EQ-5D-Y-3L are demonstrated to be valid and generally consistent for measuring HRQoL among adolescents aged 15-17 years in China. Respondents reported higher proportions of having problems using the EQ-5D-Y-3L than using the EQ-5D-3L. More research is warranted to compare the discriminant validity and test-retest reliability between the two measures.

Fair Funding Decisions: Consistency of the Time Horizons Used in the Calculation of Quality-Adjusted Life Years for Therapies for Very Rare Diseases by the National Institute for Health and Care Excellence in England

The National Institute for Health and Care Excellence (NICE) in England uses quality-adjusted life years (QALYs) to assess the cost-effectiveness of treatments. A QALY is a measure that combines the size of the clinical benefit of a treatment with the time the patient benefits from it, i.e., the time horizon. We wanted to know how consistently QALY gains are calculated at NICE. Therefore, we have analysed information on the time horizons used for the QALY calculations of the concluded evaluations conducted under the Highly Specialised Technologies programme for treatments of very rare diseases at NICE. For treatments with final guidance published by December 2023 (n = 29), a time horizon of median 97.5 years (range: 35 to 125 years) was used to calculate the QALY gains. For most QALY calculations, the accepted time horizon was longer than either the expected treatment duration or the estimated life expectancy. In contrast, for the only technology with a final negative funding decision, i.e., afamelanotide for treating the lifelong chronic disease erythropoietic protoporphyria, a time horizon that was shorter than the expected treatment duration was used. The fairness and consistency of the evaluation process of treatments for very rare diseases at NICE should be reviewed.

Development and Content Validation of Novel Patient-Reported Outcome Measures to Assess Disease Severity and Change in Patients with Erythropoietic Protoporphyria: The EPP Impact Questionnaire (EPIQ)

Purpose

Erythropoietic protoporphyria (EPP), a rare inherited disorder, presents in early childhood with severe, painful phototoxicity, with significant impacts on health-related quality of life (HRQoL). Previous studies have not captured all concepts important to patients. Therefore, this study sought to develop a novel, comprehensive, and content valid patient-reported outcome (PRO) measure to assess the efficacy of new therapies.

Patients and Methods

Qualitative interviews were conducted with EPP participants and clinical experts to obtain views on concepts relevant to patients. Results informed the development of novel PROs, which were debriefed during subsequent combined concept elicitation and cognitive debriefing interviews.

Results

Twenty-three interviews were conducted with 17 adults and 6 adolescents with EPP. Concept elicitation revealed that participants experienced many symptoms with significant variability. The most common were burning, pain, swelling, and tingling. Tingling was the most common prodromal symptom, while burning was the most bothersome, and pain was the worst full reaction symptom. Participants reported being negatively impacted in their ability to do daily activities, and social and emotional functioning. Many reported impacted ability to work and be productive at their job. Participants reviewed and completed the newly developed PRO measures assessing full reactions and ability to do activities, as well as items to assess severity and change in severity of prodromal symptoms, full reactions, and EPP overall. All measures were found to be comprehensive, clear, and relevant.

Conclusion

PRO measures are needed to assess important aspects of HRQoL and evaluate therapeutic response. These PRO measures are unique in assessing overall severity and change in EPP.

Erythropoietic protoporphyria and afamelanotide: a patient's perspective

The patient explores the profound impact of erythropoietic protoporphyria (EPP) on her life to date. The clinician’s comment reviews the symptoms and diagnostic criteria for EPP, as well as the novel treatment afamelanotide for EPP.