SF-6D health state utilities for lifestyle, sociodemographic and clinical characteristics of a large international cohort of people with multiple sclerosis

Assessing disease progression and treatment response in progressive multiple sclerosis

Progressive multiple sclerosis poses a considerable challenge in the evaluation of disease progression and treatment response owing to its multifaceted pathophysiology. Traditional clinical measures such as the Expanded Disability Status Scale are limited in capturing the full scope of disease and treatment effects. Advanced imaging techniques, including MRI and PET scans, have emerged as valuable tools for the assessment of neurodegenerative processes, including the respective role of adaptive and innate immunity, detailed insights into brain and spinal cord atrophy, lesion dynamics and grey matter damage. The potential of cerebrospinal fluid and blood biomarkers is increasingly recognized, with neurofilament light chain levels being a notable indicator of neuro-axonal damage. Moreover, patient-reported outcomes are crucial for reflecting the subjective experience of disease progression and treatment efficacy, covering aspects such as fatigue, cognitive function and overall quality of life. The future incorporation of digital technologies and wearable devices in research and clinical practice promises to enhance our understanding of functional impairments and disease progression. This Review offers a comprehensive examination of these diverse evaluation tools, highlighting their combined use in accurately assessing disease progression and treatment efficacy in progressive multiple sclerosis, thereby guiding more effective therapeutic strategies.

The subjective wellbeing of people living with Multiple Sclerosis in Australia: insights from the Personal Wellbeing Index

OBJECTIVES

Subjective wellbeing has been defined as an individual's personal appraisal of their quality of life. Subjective wellbeing is associated with positive health behaviours and improved coping abilities. This study aimed to investigate the subjective wellbeing of people living with multiple sclerosis (MS), using the novel Personal Wellbeing Index, and make comparisons with the general population.

METHODS

Cross-sectional data was obtained from the Australian Multiple Sclerosis Longitudinal Study and the How Is Your Life Australian general population study in August-October 2020. Subjective wellbeing was measured as life satisfaction using the Personal Wellbeing Index. This instrument measures life satisfaction globally and in seven life domains, allowing the importance of domain-specific life satisfaction to be explored. Descriptive and multivariable regression analyses were conducted.

RESULTS

One thousand six hundred eighty-three MS and 1,021 general population participants entered the study (mean age 52.4 and 58.6; female 79.9% and 52.4%, respectively). For people living with MS the most important life domains were standard of living and achieving in life. The domain of personal health was more influential for people living with MS (p < 0.01) than the general population. The life domains most susceptible to MS-related disability were personal health, achieving in life, and community connectedness (p < 0.01 for these domains).

CONCLUSION

Personal health and achieving in life are key domains through which the subjective wellbeing of people living with MS is modified. This study recommends the development of interventions to support healthy perceptions of illness and continued employment as paramount in improving the subjective wellbeing of people living with MS.

Cost and Quality of Life of Disability Progression in Multiple Sclerosis Beyond EDSS: Impact of Cognition, Fatigue, and Limb Impairment

BACKGROUND AND OBJECTIVE

Understanding the socioeconomic burden of multiple sclerosis (MS) is essential to inform policymakers and payers. Real-world studies have associated increasing costs and worsening quality of life (QoL) with disability progression. This study aims to further evaluate the impact of cognition, fatigue, upper and lower limb function (ULF, LLF) impairments, and disease progression per Expanded Disability Status Scale (EDSS) level, on costs and QoL.

METHODS

This was a cross-sectional cohort study including 20,988 patients from the German NeuroTransData MS registry from 2009 to 2019. QoL analyses were based on EQ-5D-5L. Cost analyses included indirect/direct medical and non-medical costs. Eight subgroups, ranging from 439 to 1812 patients were created based on presence of measures for disease progression (EDSS), cognition (Symbol Digit Modalities Test [SDMT]), fatigue (Modified Fatigue Impact 5-Item Scale [MFIS-5]), ULF (Nine-Hole Peg Test [9HPT]), and LLF (Timed 25-Foot Walk [T25FW]). Multivariable linear regression assessed the independent effect of each test's score on QoL and costs, while adjusting for EDSS and 12 other confounders.

RESULTS

Lower QoL was associated with decreasing cognition (p < 0.001), worsening ULF (p = 0.025), and increasing fatigue (p < 0.0001); however, the negative impact of LLF worsening on QoL was not statistically significant (p = 0.54). Higher costs were associated with decreasing cognition (p < 0.001), worsening of ULF (p = 0.0058) and LLF (p = 0.049), and increasing fatigue (p < 0.0001). Each 1-scale-step worsening function of SDMT, MFIS-5, 9HPT, and T25FW scores resulted in €170, €790, €330, and €520 higher costs, respectively. Modeling disability progression based on SDMT, MFIS-5, 9HPT, and T25FW scores as an interaction with EDSS strata found associations with lower QoL and higher costs at variable EDSS ranges.

CONCLUSIONS

Disease progression in MS measured by 9HPT, SDMT, and MFIS-5 had a significant negative impact on QoL and broad socioeconomic costs independent of EDSS. T25FW had a significant negative association with costs. Cognition, fatigue, ULF, and LLF have stronger impact on costs and QoL in patients with higher EDSS scores. Additional determinants of MS disability status, including SDMT, MFIS-5, 9HPT, and T25FW, should be considered for assessing cost effectiveness of novel therapeutics for MS.

Estimation of Transition Probabilities from a Large Cohort (> 6000) of Australians Living with Multiple Sclerosis (MS) for Changing Disability Severity Classifications, MS Phenotype, and Disease-Modifying Therapy Classifications

BACKGROUND

Multiple sclerosis (MS) is a chronic autoimmune/neurodegenerative disease associated with progressing disability affecting mostly women. We aim to estimate transition probabilities describing MS-related disability progression from no disability to severe disability. Transition probabilities are a vital input for health economics models. In MS, this is particularly relevant for pharmaceutical agency reimbursement decisions for disease-modifying therapies (DMTs).

METHODS

Data were obtained from Australian participants of the MSBase registry. We used a four-state continuous-time Markov model to describe how people with MS transition between disability milestones defined by the Expanded Disability Status Scale (scale 0-10): no disability (EDSS of 0.0), mild (EDSS of 1.0-3.5), moderate (EDSS of 4.0-6.0), and severe (EDSS of 6.5-9.5). Model covariates included sex, DMT usage, MS-phenotype, and disease duration, and analysis of covariate groups were also conducted. All data were recorded by the treating neurologist.

RESULTS

A total of N = 6369 participants (mean age 42.5 years, 75.00% female) with 38,837 person-years of follow-up and 54,570 clinical reviews were identified for the study. Annual transition probabilities included: remaining in the no, mild, moderate, and severe states (54.24%, 82.02%, 69.86%, 77.83% respectively) and transitioning from no to mild (42.31%), mild to moderate (11.38%), and moderate to severe (9.41%). Secondary-progressive MS was associated with a 150.9% increase in the hazard of disability progression versus relapsing-remitting MS.

CONCLUSIONS

People with MS have an approximately 45% probability of transitioning from the no disability state after one year, with people with progressive MS transitioning from this health state at a much higher rate. These transition probabilities will be applied in a publicly available health economics simulation model for Australia and similar populations, intended to support reimbursement of a plethora of existing and upcoming interventions including medications to reduce progression of MS.

Associations between diet and disease progression and symptomatology in multiple sclerosis: A systematic review of observational studies

BACKGROUND

Although many people with MS (pwMS) modify their diet after diagnosis, there is still no consensus on dietary recommendations for pwMS. A number of observational studies have explored associations of diet and MS progression, but no studies have systematically reviewed the evidence. This systematic review aimed to provide an objective synthesis of the evidence for associations between diet and MS progression, including symptoms and clinical outcomes from observational studies.

METHODS

We performed a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Electronic database searches were performed for studies completed up to 26 July 2023 using PubMed (Medline), Web of Science, CINAHL, Embase (Ovid), and Scopus, followed by citation and reference list checking. We included studies using diet quality scores or dietary indices. Studies assessing individual foods, nutrients, or dietary supplements were excluded. We used the Newcastle-Ottawa Scale to assess the risk of bias of included studies.

RESULTS

Thirty-two studies met the inclusion criteria. Of these, 20 were cross-sectional and 12 prospective. The most frequent outcomes assessed were disability (n = 19), quality of life (n = 12), fatigue (n = 12), depression (n = 9), relapse (n = 8), anxiety (n = 3), and magnetic resonance imaging (MRI) outcomes (n = 4). Based on prospective studies, this review suggests that diet might be associated with quality of life and disability. There were also potential effects of higher diet quality scores on improved fatigue, disability, depression, anxiety, and MRI outcomes but more evidence is needed from prospective studies.

CONCLUSIONS

Observational studies show some evidence for an association between diet and MS symptoms, particularly quality of life and disability. However, the impact of diet on other MS outcomes remains inconclusive. Ultimately, our findings suggest more evidence is needed from prospective studies and well-designed tailored intervention studies to confirm associations.

Higher diet quality is associated with short and long-term benefits on SF-6D health state utilities: a 5-year cohort study in an international sample of people with multiple sclerosis

BACKGROUND/PURPOSE

Health state utilities (HSU) are a subjective measure of an individual's health-related quality of life (HRQoL), adjusted by societal or patient relative preference weights for living in different states of health-related quality of life (HRQoL), derived from patient-reported responses to multi-attribute utility instrument (MAUI), and can be used as inputs for cost-utility analyses and in clinical assessment. This research assessed associations of diet with subsequent HSU in a large international cohort of people living with multiple sclerosis (MS), a progressive autoimmune condition of the central nervous system.

METHODS

HSUs were generated from responses to Short-Form Six-Dimension (SF-6D) MAUI, and quality-of-the-diet by Diet Habits Questionnaire (DHQ). Cross-sectional, and short- and long-term prospective associations of DHQ with HSU evaluated by linear regression at 2.5- and 5-years. Pooled prospective associations between DHQ and HSU evaluated using linear and quantile regression. Analyses adjusted for relevant demographic and clinical covariates.

RESULTS

Among 839 participants, baseline DHQ scores showed short- and long-term associations with subsequent HSU, each 10-unit increase in total DHQ score associated with 0.008-0.012 higher HSU (out of 1.00). These associations were dose-dependent, those in the top two quartiles of baseline DHQ scores having 0.01-0.03 higher HSU at follow-up, 0.03 being the threshold for a minimally clinically important difference. Fat, fiber, and fruit/vegetable DHQ subscores were most strongly and consistently associated with better HSU outcomes. However, baseline meat and dairy consumption were associated with 0.01-0.02 lower HSU at subsequent follow-up.

CONCLUSIONS

A higher quality-of-the-diet showed robust prospective relationships with higher HSUs 2.5- and 5-years later, substantiating previous cross-sectional relationships in this cohort. Subject to replication, these results suggest interventions to improve the quality-of-the-diet may be effective to improve HRQoL in people living with MS.

Health utility in community-dwelling adults with dysvascular lower limb loss

PURPOSE

Adults with dysvascular lower extremity amputation (LEA) experience a large number of secondary health conditions yet there is a gap in the literature on health utility scores for this population. A health utility score relates to a person's state of well-being, and is a single metric anchored at 0 (death) and 1 (perfect health). This study aimed to provide a descriptive account of health utility scores in community-dwelling adults with dysvascular LEA.

METHODS

Participants were adults with dysvascular LEA who were 3 months post-amputation. Data collected included socio-demographic characteristics, the Special Interest Group in Amputee Medicine (SIGAM) grades, the dysvascular conditions scale (DCS), which is a scale developed for this study, and the Short Form-36 (SF-36). SF-6D health utility scores were derived from the SF-36 using a software algorithm. Participants were grouped into low-impact and high-impact groups based on self-reported severity of symptoms using the DCS. Health utility scores were compared between the low-impact and high-impact groups using independent t-tests.

RESULTS

A total of 231 participants were enrolled in the study. The mean SF-6D health utility score was 0.689 (0.127). A significant association was found between health utility score and SIGAM grade (p < 0.001, η2 = .09). Health utility was positively associated with age (r = 0.137, p = 0.037) and months post-amputation (r = 0.141, p = 0.032), and negatively associated with DCS severity (r = -0.526, p < 0.001). Health utility scores were lower for participants in the DCS high-impact groups for conditions such as diabetes mellitus, phantom limb pain, musculoskeletal pain, back pain, psychological distress, depression, vision problems, and other pain.

CONCLUSION

Cost-utility analyses rely on health utility estimates and our findings provide data for future economic evaluations that may assist policy makers in evidence informed allocation of healthcare resources for this population.

Validation of the EQ-5D-5L and psychosocial bolt-ons in a large cohort of people living with multiple sclerosis in Australia

BACKGROUND

Multiple sclerosis (MS) is an inflammatory, neurodegenerative disease of the central nervous system which results in disability over time and reduced quality of life. To increase the sensitivity of the EQ-5D-5L for psychosocial health, four bolt-on items from the AQoL-8D were used to create the nine-item EQ-5D-5L-Psychosocial. We aimed to externally validate the EQ-5D-5L-Psychosocial in a large cohort of people with MS (pwMS) and explore the discriminatory power of the new instrument with EQ-5D-5L/AQoL-8D.

METHODS

A large representative sample from the Australian MS Longitudinal Study completed the AQoL-8D and EQ-5D-5L (including EQ VAS) and both instruments health state utilities (HSUs) were scored using Australian tariffs. Sociodemographic/clinical data were also collected. External validity of EQ-5D-5L-Psychosocial scoring algorithm was assessed with mean absolute errors (MAE) and Spearman's correlation coefficient. Discriminatory sensitivity was assessed with an examination of ceiling/floor effects, and disability severity classifications.

RESULTS

Among 1683 participants (mean age: 58.6 years; 80% female), over half (55%) had moderate or severe disability. MAE (0.063) and the distribution of the prediction error were similar to the original development study. Mean (± standard deviation) HSUs were EQ-5D-5L: 0.58 ± 0.32, EQ-5D-5L-Psychosocial 0.62 ± 0.29, and AQoL-8D: 0.63 ± 0.20. N = 157 (10%) scored perfect health (i.e. HSU = 1.0) on the EQ-5D-5L, but reported a mean HSU of 0.90 on the alternative instruments. The Sleep bolt-on dimension was particularly important for pwMS.

CONCLUSIONS

The EQ-5D-5L-Psychosocial is more sensitive than the EQ-5D-5L in pwMS whose HSUs approach those reflecting full health. When respondent burden is taken into account, the EQ-5D-5L-Psychosocial is preferential to the AQoL-8D. We suggest a larger confirmatory study comparing all prevalent multi-attribute utility instruments for pwMS.

Using the EQ-5D-5L to investigate quality-of-life impacts of disease-modifying therapy policies for people with multiple sclerosis (MS) in New Zealand

BACKGROUND

Health state utilities (HSU) are a health-related quality-of-life (HRQoL) input for cost-utility analyses used for resource allocation decisions, including medication reimbursement. New Zealand (NZ) guidelines recommend the EQ-5D instruments; however, the EQ-5D-5L may not sufficiently capture psychosocial health. We evaluated HRQoL among people with multiple sclerosis (MS) in NZ using the EQ-5D-5L and assessed the instrument's discriminatory sensitivity for a NZ MS cohort.

METHODS

Participants were recruited from the NZ MS Prevalence Study. Participants self-completed a 45-min online survey that included the EQ-5D-5L/EQ-VAS. Disability severity was classified using the Expanded Disability Status Scale (EDSS) to categorise participant disability as mild (EDSS: 0-3.5), moderate (EDSS: 4.0-6.0) and severe (EDSS: 6.5-9.5). Anxiety/depression were also measured using the Hospital Anxiety and Depression Score (HADS). In the absence of an EQ-5D-5L NZ tariff, HSUs were derived using an Australian tariff. We evaluated associations between HSUs and participant characteristics with linear regression models.

RESULTS

254 participants entered the study. Mean age was 55.2 years, 79.5% were female. Mean (SD) EQ-5D-5L HSU was 0.58 (0.33). Mean (SD) HSUs for disability categories were: mild 0.80 ± 0.17, moderate 0.57 ± 0.21 and severe 0.14 ± 0.32. Twelve percent reported HSU = 1.0 (i.e., no problems in any domain). Participants who had never used a disease-modifying therapy reported a lower mean HSU. Multivariable modelling found that the HADS anxiety score was not associated with EQ-5D-5L.

CONCLUSIONS

HRQoL for people with MS in NZ was lower than comparable countries, including Australia. We suggest a comparison with other generic tools that may have improved sensitivity to mental health.

Population norms for quality adjusted life years for the United States of America, China, the United Kingdom and Australia

Health economics uses quality adjusted life years (QALYs) to help healthcare decision makers. However, unlike life expectancy for which age- and sex-dependent national life tables are available, no general population norms exist to use as a benchmark against which to compare observed or modeled projections of QALYs in sub-populations or patients. We developed a 2-state Markov model to generate QALY population norms for the USA, UK, China and Australia. Annual age- and sex-specific probabilities of all-cause mortality were taken from life tables combined with general population country-specific age- and sex-specific health state utilities for the EQ-5D-3L (all countries); and SF-6D (Australia) multi-attribute utility instruments (MAUI). To validate our QALY benchmark model we found that the model closely predicted population life expectancies. Using EQ-5D-3L, undiscounted QALYs for males/females aged 18 years ranged 54.62/58.90 (USA), 55.55/60.21 (China), 57.11/60.16 (Australia), and 58.01/61.43 (UK) years. SF-6D benchmark QALYs for Australia were consistently lower than those generated from the EQ-5D-3L. The gap in undiscounted QALYs between the UK (highest) and the USA (lowest) was 2.53 QALYs in women and 3.39 QALYs in men aged 18 years. Our model's QALY population norms can be used for internal validation of future health economic models for the country-specific value sets for the instruments that we adopted, and when quantifying burden of disease in terms of QALYs lost due to illness compared to the general population. We have created a publicly available repository to continuously include QALY benchmarks that use country-specific value sets for other MAUIs and life expectancies.

Factors that influence quality of life in patients with multiple sclerosis in Saudi Arabia

PURPOSE

To study the factors which may contribute to quality of life (QOL) in patients with multiple sclerosis (pwMS) in Saudi Arabia.

METHODS

175 pwMS and 71 age-, gender-, and BMI-matched healthy subjects participated in this cross-sectional study. QOL was studied by the multiple sclerosis quality of life-54 (MSQOL-54) while depression, disability, and fatigue were measured by the beck depression inventory-II (BDI-II), the expanded disability status scale (EDSS), and the modified fatigue impact scale (MFIS), respectively. The effects of demographic and clinical characteristics on MSQOL-54 were studied.

RESULTS

QOL was worse in pwMS. A better QOL in pwMS was linked to being male, having relapsing-remitting MS, having lower BMI, being employed, having a low disability, having no or minimal depression, and not fatigued. Age, disease duration, marital status, living status, and level of education did not affect the QOL. QOL showed a moderate to strong correlation with depression and fatigue and a weak correlation with EDSS. Depression and fatigue were the strongest predictors of QOL. Other predictors included gender and BMI but not EDSS.

CONCLUSIONS

Many of the factors which seem to influence QOL in pwMS are modifiable. Evaluation and management of such factors may improve QOL in pwMS.Implications for rehabilitationAssessment of QOL (using a proper tool) should be part of every pwMS evaluation.Depression and fatigue are the main predictors of QOL in pwMs, therefore, attention should be paid for their evaluation and management.Sexual dysfunction and pain should be assessed and managed early in the course of the disease.

Association between knee symptoms, change in knee symptoms over 6-9 years, and SF-6D health state utility among middle-aged Australians

OBJECTIVES

Health state utilities (HSUs) are an input metric for estimating quality-adjusted life-years (QALY) in cost-utility analyses. Currently, there is a paucity of data on association of knee symptoms with HSUs for middle-aged populations. We aimed to describe the association of knee symptoms and change in knee symptoms with SF-6D HSUs and described the distribution of HSUs against knee symptoms' severity.

METHODS

Participants (36-49-years) were selected from the third follow-up (completed 2019) of Australian Childhood Determinants of Adult Health study. SF-6D HSUs were generated from the participant-reported SF-12. Association between participant-reported WOMAC knee symptoms' severity, change in knee symptoms over 6-9 years, and HSUs were evaluated using linear regression models.

RESULTS

For the cross-sectional analysis, 1,567 participants were included; mean age 43.5 years, female 54%, BMI ± SD 27.18 ± 5.31 kg/m². Mean ± SD HSUs for normal, moderate, and severe WOMAC scores were 0.820 ± 0.120, 0.800 ± 0.120, and 0.740 ± 0.130, respectively. A significant association was observed between worsening knee symptoms and HSUs in univariable and multivariable analyses after adjustment (age and sex). HSU decrement for normal-to-severe total-WOMAC and WOMAC-pain was - 0.080 (95% CI - 0.100 to - 0.060, p < 0.01) and - 0.067 (- 0.085 to - 0.048, p < 0.01), exceeding the mean minimal clinically important difference (0.04). Increase in knee pain over 6-9 years was associated with a significant reduction in HSU.

CONCLUSION

In a middle-aged population-based sample, there was an independent negative association between worse knee symptoms and SF-6D HSUs. Our findings may be used by decision-makers to define more realistic and conservative baseline and ongoing HSU values when assessing QALY changes associated with osteoarthritis interventions.