Preferences and Utilities for Treatment Attributes in Type 2 and Non-ambulatory Type 3 Spinal Muscular Atrophy in the United Kingdom

Disutilities of treatment-related attributes for type 2 diabetes mellitus: a systematic review

OBJECTIVES

To synthesize the literature on eliciting disutilities associated with treatment-related attributes in type 2 diabetes (T2DM).

METHODS

We searched Medline, Embase, Cochrane Library, PsycINFO, EconLit and CINAHL databases from inception to December, 2024. This systematic review followed PRISMA guidelines, quality and risk of bias of the included studies were assessed using the NICE and ROBINS-I checklist.

RESULTS

Nine studies involving 59 to 4060 participants were included and most studies (n=6) were conducted in the UK. The perspective of preference included T2DM patients (n=7) and the general public (n=3), with one study included both. Elicitation approaches used were time trade-off (n=5) and standard gamble (n=4). Eight treatment-related attributes were identified, including weight change (n=5), dosing frequency (n=4), gastrointestinal side effects (n=2), flexible dosing (n=2), administration requirement (i.e., reconstitution, waiting, and needle handling) (n=2), injection site reaction (n=1), fear of hypoglycemia (n=1), and HbA1c levels (n=1). For the attribute of weight change, the (dis)utility value ranged from -0.106 to 0.047. Respondents showed a preference for weekly over daily administration (range: 0.023 to 0.095), once-daily over multiple-daily (range: 0.015 to 0.123). The (dis)utility values for the rest of six attributes ranged from -0.04 to 0.034.

CONCLUSIONS

This review provides evidence synthesize of published disutilities related to T2DM treatment-related attributes which have a nonnegligible effect. Weight change and dosing frequency were the most reported with the largest impact. Given the considerable heterogeneity in current studies, care should be taken in selecting appropriate estimates between different elicitation methods, populations and countries.

Estimating health state utilities for aromatic L-amino acid decarboxylase deficiency (AADCd) in the United States

BACKGROUND

AADCd is a rare neurometabolic disorder presenting in infancy. Children with AADCd have motor dysfunction and development delays that result in the need for lifelong care; quality of life is greatly impacted. Current characterizations of health-related quality of life and associated health state utilities (HSUs) may be underestimated in AADCd. Accurate characterization of AADCd burden is important when evaluating the benefits of treatment, especially the improvements observed with the recently approved disease-modifying therapy eladocagene exuparvovec. Time-trade-off (TTO) vignette methods may be used to elicit HSUs in AADCd for assessing the value of new treatments. This study aimed to first update previously published health state vignettes, then estimate AADCd HSUs in the United States (US).

METHODS

Existing vignettes for five AADCd health states were updated based on the review of published literature and clinician/caregiver input. Health states included: "bedridden/no motor function," "head control," "sitting unassisted," "standing with support," "walking with assistance." Online composite TTO interviews were conducted 1:1 with adults from the US general public. Participants ranked health states in order of preference using a visual analog scale, then were presented with health state vignettes to elicit utilities using TTO. Mean TTO scores were calculated for each health state, and regression models were used to estimate disutility associated with use of feeding tube.

RESULTS

Following revision of the vignettes, 120 participants completed the TTO task (mean age: 47 years; 50% female; 70% White); characteristics were not significantly different from US population norms in terms of age, sex, race or ethnicity. Six participants who appeared to misunderstand the exercise were excluded. Mean (SD) HSUs were: -0.258 (0.534) for bedridden state, -0.155 (0.569) for head control, 0.452 (0.523) for sitting unassisted, 0.775 (0.242) for standing with support, and 0.796 (0.235) for walking with assistance. The need for a feeding tube was associated with a disutility of 0.07.

CONCLUSIONS

This study implemented TTO methods to estimate utilities for five health states which reflect the burden and impact of AADCd. The range in values from the most to least severe health state suggests that there is potential for effective treatments to substantially improve quality of life in these patients.

Adherence and Persistence to Nusinersen for Spinal Muscular Atrophy: A US Claims-Based Analysis

INTRODUCTION

Spinal muscular atrophy (SMA) is a genetic, neuromuscular disease caused by deletions and/or mutations in the survival of motor neuron 1 (SMN1) gene leading to reduced SMN protein levels. Nusinersen, an intrathecally administered antisense oligonucleotide therapy that increases SMN protein levels, is approved for use in adult and pediatric patients with SMA. Data to inform real-world patient adherence and persistence to nusinersen are limited, with disparities in the population with SMA, study design, and results. The objective of this study is to characterize real-world nusinersen adherence and persistence in patients with SMA.

METHODS

This retrospective study examined nusinersen adherence and persistence over a 2-year period in patients with SMA in the USA from the IQVIA PharMetrics Plus claims database. Patients were followed from the date of first evidence of nusinersen treatment (occurring after 1 July 2017) until the end of the study period (31 December 2019) or end of continuous pharmacy and medical benefit enrollment, whichever came first. Subgroup analyses for nusinersen adherence and persistence were performed on the basis of age and presence or absence of spinal complications.

RESULTS

The final cohort consisted of 179 patients with SMA treated with nusinersen. Adherence to nusinersen treatment was 41% at 56 weeks and 39% at 104 weeks. In the base-case persistence analysis, there was a decrease in persistence before 6 months (67%) and further decline at 1 (57%) and 2 years (55%). Patients with spinal complication versus without had numerically higher persistence with nusinersen.

CONCLUSIONS

The findings suggest that adherence and persistence to nusinersen treatment appear low. Demographic (age ≥ 18 years) and clinical factors (no spinal complications) may contribute to nusinersen treatment discontinuation. Future research should explore possible reasons for low adherence and persistence to nusinersen treatment, such as clinical or logistical factors, patient preferences, and payer restrictions.

Utility estimations of different health states of patients with type I, II, and III spinal muscular atrophy in China: A mixed approach study with patient and proxy-reported data

Introduction

Spinal muscular atrophy (SMA) is a rare autosomal-recessive neuromuscular disease. Health state utility values (HSUV) are used in health economic evaluation regarding the desirability of health outcomes such as a certain health state or change in health states over time. There is no utility data of Chinese patients with SMA.

Materials and methods

Vignettes were developed for 10 pediatric neurologists to value the utility of Chinese patients with Type I SMA. A mixed patient/proxy derived approach using EQ-5D-Y-3L, EQ-5D-3L, and CHU9D was adopted to estimate the HSUV data of patients with Type II and III SMA, including 112 patients and 301 caregivers.

Result

The utility of Type I SMA patients ranged from 0.19 to 0.72 with the health state improved from "permanent ventilation" to "walking". The utility of children patients with Type II and III SMA derived from EQ-5D-Y-3L ranged from 0.33 to 0.82 while that derived from CHU9D ranged from 0.46 to 0.75. The utility of adult patients with Type II and III SMA measured by EQ-5D-3L ranged from 0.30 to 0.83.

Conclusion

The better health states the patients with SMA were in, the higher were the HSUV. The utilities derived from population with different age and disease subtypes were not statistically different when patients with SMA were in the same health states. We recommend further studies on the Chinese specific value set for EQ-5D-Y-3L and other PBMs for children to derive more robust utility data.