The FACT-8D, a new cancer-specific utility algorithm based on the Functional Assessment of Cancer Therapies-General (FACT-G): a Canadian valuation study

Comparing the measurement properties of the EQ-5D-5 L, SF-6Dv2, QLU-C10D and FACT-8D among survivors of classical Hodgkin's lymphoma

OBJECTIVE

This study aimed to evaluate the measurement properties of EQ-5D-5 L, SF-6Dv2, QLU-C10D, and FACT-8D in survivors of Classical Hodgkin's Lymphoma (CHL).

METHODS

A cross-sectional, web-based survey was conducted from May to August 2022 to collect data. Chinese value sets were used to estimate the utility scores for EQ-5D-5 L, SF-6Dv2, and QLU-C10D, while the Australian value set was used for FACT-8D. The measurement properties assessed included ceiling and floor effects, convergent validity (assessing associations between similar dimensions/utility scores using Spearman's rank correlation and intraclass correlation coefficient), and known-group validity (measures could differentiate health-related quality of life (HRQoL) between risk groups).

RESULTS

A total of 534 CHL survivors participated in the survey and completed the questionnaire. All dimensions of EQ-5D-5 L, SF-6D (except for vitality), QLU-C10D, and FACT-8D showed ceiling effects, ranging from 18 to 91.6%. The EQ-5D-5 L demonstrated the higher ceiling effects compared to other measures, with 33% of patients reporting full health on this scale. All 30 pairs of associations between similar dimensions from the four measures were statistically significant, with correlation coefficients ranging from 0.29 to 0.77. Regarding utility scores, the EQ-5D-5 L utility score showed a stronger correlation with SF-6Dv2 than with the other two measures. Statistically significant correlations of utility scores between the four measures were observed. EQ-5D-5 L can significantly differentiate HRQoL among all known-groups, while SF-6Dv2, QLU-C10D, and FACT-8D showed a less strong discriminant ability.

CONCLUSIONS

EQ-5D-5 L outperformed SF-6Dv2 in terms of agreement with cancer-specific PRMs and discriminant ability. However, SF-6Dv2 showed stronger associations with similar dimensions of QLU-C10D and FACT-8D, indicating high convergent validity. The generic PBMs are sensitive enough to measure HRQoL in survivors of CHL.

The Evolving Landscape of Discrete Choice Experiments in Health Economics: A Systematic Review

INTRODUCTION

Stakeholder preference evaluations are increasingly emphasized in healthcare policy and health technology assessment. Discrete choice experiments (DCEs) are the most common method for quantifying preferences among patients, the public, and healthcare professionals. While prior reviews (1990-2017) have examined DCE trends, no comprehensive synthesis exists for studies published since 2018. This updated review (2018-2023) provides critical insights into evolving methodologies and global trends in health-related DCEs.

METHODS

A systematic search (2018-2023) of Medline, Embase, and Web of Science identified relevant studies. Studies were screened for inclusion and data were extracted, including details on DCE design and analysis. To enable trend comparisons, the search strategy and extraction items aligned with previous reviews.

RESULTS

Of 2663 identified papers, 1279 met the inclusion criteria, reflecting a significant rise in published DCEs over time. DCEs were conducted globally, with a remarkable increase in publications from Asia and Africa compared with previous reviews. Experimental designs and econometric models have advanced, continuing prior trends. Notably, most recent DCEs were administered online.

DISCUSSION

The rapid growth of DCE applications underscores their importance in health research. While the methodology is advancing rapidly, it is crucial that researchers provide full transparency in reporting their methods, particularly in detailing experimental designs and validity tests, which are too often overlooked. Key recommendations include improving reporting of experimental designs, applying validity tests, following good practices for presenting benefit-risk attributes, and adopting open science practices. Ensuring methodological rigor will maximize the impact and reproducibility of DCE research in health economics.

Validation of the Cancer-Specific Preference-Based Measure EORTC QLU-C10D against the Generic Instruments EQ-5D-5L and SF-6Dv2 in a Prospectively Collected Sample of Patients with Cancer in Austria and France

BACKGROUND

The Quality of Life Utility - Core 10 Dimensions (QLU-C10D) is a disease-specific preference-based measure (PBM) designed to obtain health state utility values from patients with cancer. Previously, satisfactory psychometric properties were established from retrospective trial analyses using clinical anchors. This study aimed to validate the QLU-C10D against two generic PBMs in a prospective sample of Austrian and French patients with cancer using patient-reported anchors.

METHODS

Patients completed the European Organisation of Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire - Core 30 (QLQ-C30), EQ-5D-5L and Short Form 36 (SF-36) at study baseline (any time during anti-cancer treatment) plus a follow-up assessment 3-6 months later. Sociodemographic and clinical characteristics were assessed. QLU-C10D and SF-6Dv2 utilities were calculated from QLQ-C30 and SF-36 data, respectively. German, French and UK value sets were applied for all three PBMs. Floor and ceiling effects were assessed. Known-group validity (independent t-test) and responsiveness (paired t-tests) were assessed respectively by ability to detect health status differences and changes over time according to patient-rated overall quality of life/health perception assessed by the QLQ-C30 Global Health Status scale, the EQ-5D-5L VAS and the SF-36 General Health scale.

RESULTS

A total of 465 patients were included in the analysis. QLU-C10D index scores (intra-class correlation) and domains (Pearson) were correlated with EQ-5D-5L and Short-Form Six Dimensions (SF-6Dv2) conceptual counterparts. Correlation coefficients for the index scores of QLU-C10D and the generic PBMs ranged from 0.63 to 0.81. The QLU-C10D detected statistically significant differences between groups at baseline in 100% of tests performed (n = 27). For changes over time, QLU-C10D detected expected effects in 68% of cases (n = 29). In comparison with the generic PBMs, QLU-C10D detected differences and changes with a higher statistical efficiency in 76% of cases (77 of 102).

CONCLUSIONS

The QLU-C10D is a fit-for-purpose ready-to-use PBM to estimate health state utilities of patients with cancer. This study adds to evidence that QLU-C10D has appropriate psychometric properties and appears to have higher statistical efficiency than generic PBMs in cancer.

Developing a utility value set for the Gambling Quality of Life Scale-Brief (GQoLS-Brief) using a discrete choice experiment

OBJECTIVES

The Gambling Quality of Life Scale -brief (GQoLS-Brief) assesses the impact of gambling disorder (GD) on quality of life (QoL). Preference-based measures are essential for obtaining the quality adjustment weight (i.e. utility score) needed to calculate quality-adjusted life years (QALYs) in economic evaluations. We aimed to derive a value set for the GQoLS-Brief.

METHODS

We employed a discrete choice experiment for preference elicitation. An online survey was administered (n = 928). Respondents completed 10 choice tasks, each presenting two GQoLS-Brief health states alongside life expectancy. Conditional logit regression, parameterized to fit the QALY framework, was used for data analysis. QALY weights for each health state defined by the GQoLS-Brief were calculated.

RESULTS

The estimated coefficients from the conditional logit models aligned with expectations: utility increased with survival time and decreased with QoL impairment. Utility values for health states ranged from - 1.48 (worse than death) to 1.0. "Financial difficulties" exhibited the highest utility decrement, followed by "Sleep disturbance related to financial difficulties."

CONCLUSIONS

This reference set facilitates the calculation of QALYs for economic evaluations of GD interventions. The weight of subjective financial difficulties underscores the need for therapeutic interventions to target this aspect.

Assessing the reliability of a novel cancer-specific multi-attribute utility instrument (FACT-8D) and comparing its validity to EQ-5D-5L in colorectal cancer patients

OBJECTIVE

To examine the test-retest reliability of the Functional Assessment of Cancer Therapy - 8 Dimension (FACT-8D) for the first time, and to conduct a head-to-head comparison of the distribution properties and validity between the FACT-8D and EQ-5D-5L in Colorectal Cancer (CRC) Patients.

METHODS

We conducted a longitudinal study on Chinese CRC patients, employing Functional Assessment of Cancer Therapy-General (FACT-G) and EQ-5D-5L at baseline, and FACT-G during follow-up (2-7 days from baseline). Utility scores for FACT-8D were derived from all available value sets (Australia, Canada and USA), while EQ-5D-5L scores were obtained from corresponding value sets for various countries. We assessed convergent validity using pairwise polychoric correlations between the FACT-8D and EQ-5D-5L; known-groups validity by discriminating participants' clinical characteristics, and effect size (ES) was tested; test-retest reliability for FACT-8D using kappa and weighted Kappa for choice consistency, and intraclass correlation coefficient (ICC) and Bland-Altman method for utility consistency.

RESULTS

Among the 287 patients with CRC at baseline, 131 were included in the retest analysis. The utility scores of FACT-8D were highly positively correlated with EQ-5D-5L across various country value sets (r = 0.65-0.77), and most of the dimensions of FACT-8D and EQ-5D-5L were positively correlated. EQ-5D-5L failed to discriminate known-groups in cancer stage across all value sets, whereas both were significant in FACT-8D (ES = 0.35-0.48, ES = 0.38-0.52). FACT-8D showed good test-retest reliability (Cohen's weighted Kappa = 0.494-0.722, ICC = 0.748-0.786).

CONCLUSION

The FACT-8D can be used as a valid and reliable instrument for clinical evaluation of patients with CRC, outperforming EQ-5D-5L in differentiating clinical subgroups and showing promise for cancer practice and research.

Valuing quality of life for economic evaluations in cancer: navigating multiple methods

INTRODUCTION

Utility values offer a quantitative means to evaluate the impact of novel cancer treatments on patients' quality of life (QoL). However, the multiple methods available for valuing QoL present challenges in selecting the most appropriate method across different contexts.

AREAS COVERED

This review provides cancer clinicians and researchers with an overview of methods to value QoL for economic evaluations, including standalone and derived preference-based measures (PBMs) and direct preference elicitation methods. Recent developments are described, including the comparative performance of cancer-specific PBMs versus generic PBMs, measurement of outcomes beyond health-related QoL, and increased use of discrete choice experiments to elicit preferences. Recommendations and considerations are provided to guide the choice of method for cancer research.

EXPERT OPINION

We foresee continued adoption of the QLU-C10D and FACT-8D in cancer clinical trials given the extensive use of the EORTC QLQ-C30 and FACT-G in cancer research. While these cancer-specific PBMs offer the convenience of eliciting utility values without needing a standalone PBM, researchers should consider potential limitations if they intend to substitute them for generic PBMs. As the field advances, there is a greater need for consensus on the approach to selection and integration of various methods in cancer clinical trials.

A comparison of measurement properties between EORTC QLU-C10D and FACT-8D in patients with hematological malignances

OBJECTIVE

To perform a comparison of the measurement properties of two cancer-specific Multi-Attribute Utility Instruments (MAUIs), EORTC QLU-C10D and FACT-8D, in Chinese patients with hematologic malignancies (HM).

METHODS

We conducted a longitudinal study on patients with HM in China, using QLU-C10D and FACT-8D at baseline and follow-up (3-4 months from baseline). We assessed: (i) convergent validity using Spearman's rank correlation test (r) with EQ-5D-5L; (ii) clinical-groups validity by differentiating cancer stages, overall health assessment (OHA), Eastern Cancer Oncology Group (ECOG) performance status, and mental health status. We also examined clinical validity with effect size (ES) and relative efficiency (RE); (iii) responsiveness to changes in patient self-perception using receiver operating characteristics (ROC) curves and area under the curves (AUC); and (iv) agreement using intraclass correlation coefficients (ICC) and visualized with Bland-Altman plot.

RESULTS

Among the 308 patients with HM at baseline, 131 completed the follow-up survey. Agreement between the two measures was high (ICC = 0.76). Both measures were highly correlated with EQ-5D-5 L and significantly differentiated (p < 0.001) among groups categorized by cancer stage, OHA performance status, and mental health. ESs for QLU-C10D were numerically higher for cancer stage, OHA, and performance status (ES = 0.53-1.49), whereas ES was higher for FACT-8D and mental health status (ES = 1.35). Responsiveness was higher for QLU-C10D (AUC = 0.84) compared to FACT-8D (AUC = 0.78).

CONCLUSION

Both QLU-C10D and FACT-8D are valid cancer-specific MAUIs for evaluating patients with HM. However, scholars should consider their slight differences in focus when choosing between the two measures.

United States Value Set for the Functional Assessment of Cancer Therapy-General Eight Dimensions (FACT-8D), a Cancer-Specific Preference-Based Quality of Life Instrument

OBJECTIVES

To develop a value set reflecting the United States (US) general population's preferences for health states described by the Functional Assessment of Cancer Therapy (FACT) eight-dimensions preference-based multi-attribute utility instrument (FACT-8D), derived from the FACT-General cancer-specific health-related quality-of-life (HRQL) questionnaire.

METHODS

A US online panel was quota-sampled to achieve a general population sample representative by sex, age (≥ 18 years), race and ethnicity. A discrete choice experiment (DCE) was used to value health states. The valuation task involved choosing between pairs of health states (choice-sets) described by varying levels of the FACT-8D HRQL dimensions and survival (life-years). The DCE included 100 choice-sets; each respondent was randomly allocated 16 choice-sets. Data were analysed using conditional logit regression parameterized to fit the quality-adjusted life-year framework, weighted for sociodemographic variables that were non-representative of the US general population. Preference weights were calculated as the ratio of HRQL-level coefficients to the survival coefficient.

RESULTS

2562 panel members opted in, 2462 (96%) completed at least one choice-set and 2357 (92%) completed 16 choice-sets. Pain and nausea were associated with the largest utility weights, work and sleep had more moderate utility weights, and sadness, worry and support had the smallest utility weights. Within dimensions, more severe HRQL levels were generally associated with larger weights. A preference-weighting algorithm to estimate US utilities from responses to the FACT-General questionnaire was generated. The worst health state's value was -0.33.

CONCLUSIONS

This value set provides US population utilities for health states defined by the FACT-8D for use in evaluating oncology treatments.

Psychometric validation of the French Multidimensional Chronic Asthenia Scale (MCAS) in a sample of 621 patients with chronic fatigue

BACKGROUND

Psychometric validation of the Multidimensional Chronic Asthenia Scale (MCAS) was conducted in order to provide an effective tool for assessing the health-related quality of life of French-speaking patients with chronic asthenia (CA).

METHODS

Items resulting from the initial formulation of the self-reported MCAS (along with other materials) were completed by French-speaking volunteers with inactive or active inflammatory bowel disease (IBD-I vs. IBD-A) or chronic fatigue syndrome (CFS). Responses from 621 participants (180 patients with IBD-A, 172 with IBD-I, 269 with CFS) collected in a single online survey were divided into three subsamples to test the construct validity of the MCAS (Step 1, N = 240), to confirm its factorial structure (Step 2, N = 204) and to explore its convergent-discriminant validity with the Fatigue Symptoms Inventory (FSI) and revised Piper Fatigue Scale (r-PFS, Step 3, N = 177).

RESULTS

Steps 1 and 2 showed that, as expected, MCAS has four dimensions: feeling of constraint (FoC), physical (PC), life (LC) and interpersonal consequences (IC), which are also related to the duration of CA (i.e., the longer it lasts, the more the dimensions are impacted). The results further showed that the MCAS is sensitive enough to capture between-group differences, with the CFS group being the most impaired, followed by IBD-A and IBD-I. While convergent-discriminant validity between the 4 factors of MCAS and FSI and r-PFS, respectively, was satisfactory overall, Step 3 also pointed to some limitations that call for future research (e.g., shared variances between the PC and IC dimensions of MCAS and behavioral dimension of r-PFS).

CONCLUSION

Despite these limitations, the MCAS clearly constitutes a promising tool for measuring quantitative differences (i.e., severity/intensity) in CA associated with various diseases, but also, and importantly, the clinically important differences in domains of its expression (i.e., qualitative differences).