Estimating health state utilities in primary hyperoxaluria type 1: a valuation study.

AIMS: Quantitative data on health state utilities in primary hyperoxaluria type 1 (PH1) are lacking. This study was conducted to estimate utility values in PH1 using 3 standard valuation techniques. MATERIALS AND METHODS: Health state vignettes were developed with input from expert clinicians to describe different stages of chronic kidney disease (CKD) within the setting of PH1, along with a post-combined liver and kidney transplant (CLKT) health state ≥12 months following transplantation. The utility associated with living in each PH1 health state, as described by the vignettes, was evaluated by members of the UK general public using standard utility assessment techniques, including EQ-5D-5L, Visual Analog Scale, and Time Trade-Off. RESULTS: A similar pattern across the three valuation methods was observed. Utility values were roughly constant from CKD stage 1-3b and then dropped sharply from these states to CKD stage 4. Decreases in utility in the later stages of CKD (stages 4-5) were followed by a recovery in quality of life in the post-CLKT health state. LIMITATIONS: Vignettes may not fully capture the burden of living with PH1. CONCLUSIONS: This study serves as an informative source of data on how the burden of PH1 varies across disease stages of CKD and post-CLKT in patients with PH1. The study findings highlight the unique clinical features of PH1 compared with non-PH1-related CKD, such as the need for earlier and more intensive hemodialysis, the risk of systemic oxalosis, and the potential need for CLKT (as opposed to kidney-only transplant). The impact of PH1 on health-related quality of life, which worsens once hemodialysis is required and systemic disease manifestations occur, is captured in this study using quantitative health state utilities. These data provide an understanding of the impact of PH1 on health-related quality of life and will facilitate health economic evaluation of future treatments.

Primary hyperoxaluria type 1 (PH1) is a rare genetic disease in which the body produces too much oxalate, leading to kidney damage. Over time it can affect other organs such as the bones, the heart, and the eyes. As kidney damage progresses, patients with PH1 eventually need to receive kidney dialysis. New and emerging treatments aim to reduce oxalate production. To assess the economic value of treatments, data are needed on the quality of life of patients in different stages of PH1. This study collected these data using standard valuation methods. First, we developed written descriptions of different stages of PH1 using expert clinical input and information from published studies. Then, members of the UK general public valued the descriptions in three ways: via a survey called EQ-5D-5L (which asks participants about their mobility, self-care, usual activities, pain/discomfort, and anxiety/depression), via EQ-VAS (a visual scale, resembling a ruler, used to rate quality of life), and via time trade-off (in which participants were asked how many years of perfect health they would give up to avoid living in each disease stage described). The results show that PH1 is likely to have a considerable impact on patients' quality of life, especially in advanced stages, when dialysis is needed and multiple organs are impacted. The study provides measurable estimates of quality of life in people with PH1, which helps healthcare providers, policy makers, and payers understand the disease burden of PH1. The results can also be used in economic evaluation of new treatments.

Quantifying the impact of symptomatic acute hepatic porphyria on well-being via patient-reported outcomes: Results from the Porphyria Worldwide Patient Experience Research (POWER) study.

Acute hepatic porphyria (AHP) is a group of rare genetic diseases of heme biosynthesis resulting in severe neurovisceral attacks and chronic complications that negatively impact patients' well-being. This study evaluated the impacts of AHP on patients' physical and emotional health from a global perspective. Adult patients from the United States, Italy, Spain, Australia, Mexico, and Brazil with AHP with >1 porphyria attack within the past 2 years or receiving intravenous hemin and/or glucose for attack prevention completed an online survey assessing demographics, health characteristics, and patient-reported outcomes. Results were analyzed collectively and by patient subgroups. Ninety-two patients with AHP across the six countries completed the survey. More than 70% of patients reported that their physical, emotional, and financial health was fair or poor. Among patients who reported pain, fatigue, and muscle weakness, 94.3%, 95.6%, and 91.4%, respectively, reported that these symptoms limited daily activities. Moderate to severe depression was present in 58.7% of patients, and moderate to severe anxiety in 48.9% of patients. Of the 47% of patients who were employed, 36.8% reported loss in productivity while at work. Among patients, 85.9% reported that they had to change or modify goals that were important to them because of AHP. Aside from differences in healthcare utilization and pain severity, scores did not significantly vary with attack rate or use of hemin or glucose prophylactic treatments. AHP substantially impacts patients' physical and emotional well-being, regardless of hemin or glucose prophylactic treatment or frequency of attacks. This multinational study demonstrates that there is substantial disease burden for patients with AHP, even among those experiencing sporadic attacks or using prophylactic treatment.

Patient Perspective on Acute Hepatic Porphyria with Sporadic Attacks: A Chronic Disease with Substantial Health-Related Quality of Life Impacts.

INTRODUCTION: Acute hepatic porphyria (AHP) is a family of rare metabolic diseases characterized by potentially life-threatening acute attacks and, in some patients, chronic debilitating symptoms. While patients with frequent or recurrent attacks (three or more attacks annually) are known to have reduced health-related quality of life (HRQoL) as most aspects of daily living are impacted, limited data exist in patients with sporadic attacks. This research aims to identify porphyria-related symptoms between attacks, characterize the frequency, severity, and bothersomeness of these symptoms, and more generally understand the burden of this disease in patients who experience attacks sporadically. METHODS: Patients with AHP with sporadic attacks (AHP-SA) (at least one porphyria attack in the past 2 years, but no more than two attacks per year in the previous 2 years) were recruited, via outreach performed by patient advocacy groups, for participation in qualitative telephone interviews. Interviews were conducted using a semi-structured guide and were audio-recorded, transcribed, anonymized, coded, and analyzed to determine if saturation was reached. RESULTS: A total of 14 participants with AHP-SA were interviewed (mean age 45 years, 100% female). The most frequently reported chronic symptoms were fatigue, pain, heartburn, and constipation. The most frequently experienced chronic impacts were difficulty performing daily activities, difficulty exercising, negative impact on work, need for a special diet, anxiety, and depression. Beyond these chronic symptoms and impacts, participants also frequently described flares in their porphyria that were severe, did not qualify in their minds as an acute attack, but were nonetheless more severe than their typical chronic experience. CONCLUSION: Patients with acute hepatic porphyria who experience sporadic attacks face significant chronic symptoms and impacts that frequently require significant pharmacological and clinical treatment. The reported severity of these symptoms and impacts suggests that the humanistic burden of AHP-SA is substantial and may lead to a significant decrease in health-related quality of life in these patients between acute attacks. The presence of flares that do not reach the level of what is considered an acute attack by patients is a unique finding of this study not reported elsewhere and requires additional investigation.

Patient and caregiver experiences of living with acute hepatic porphyria in the UK: a mixed-methods study.

BACKGROUND: This study used quantitative and qualitative research methods to analyze how acute hepatic porphyria (AHP) affects patients with varying annualized porphyria attack rates. The overall impact of AHP on patients and caregivers, including their quality of life, was explored. The nature and treatment of acute attacks, experiences of long-term heme arginate treatment and access to other appropriate treatment, and the extent of and treatment for chronic symptoms were also investigated within this study. METHODS: Patient and caregiver data were collected via an online survey of members of the British Porphyria Association, followed by an optional 1-h telephone interview. RESULTS: Thirty-eight patients and 10 caregivers responded to the survey. Of those, 10 patients and three caregivers completed follow-up interviews. Overall, 19 patients (50%) had experienced an acute attack within the previous 2 years, and the severity and types of symptoms experienced during or between acute attacks varied considerably. There were no clear definitions among patients for 'mild' or 'severe' attacks. Treatments and treatment settings used to manage attacks also varied. Following unsatisfactory care experiences at hospitals, some patients reported avoiding further hospital services for later attacks. Therefore, using settings of care as a measure of attack severity should be avoided. Ninety-four percent of patients also experienced chronic symptoms, which were as varied as acute attacks. Pain was the predominant chronic symptom and was managed with opioids in severe cases. Regardless of AAR, porphyria heavily impacted the daily lives of patients and caregivers. Although patients experiencing frequent attacks generally endured a greater impact on their daily life, patients with less frequent attacks also experienced impacts on all domains (social, leisure activities, relationship with family, relationships, psychological wellbeing, finances, employment, and study). Caregivers were most affected in the finance, relationships with family, and employment domains, and just over half of the caregivers reported a moderate impact on their psychological wellbeing. CONCLUSIONS/IMPLICATIONS: The burden of illness with AHP is high across all patients, regardless of frequency of attacks, and AHP negatively affects patients and caregivers alike.