EuroQol-5 dimensions utility gain according to British and Swedish preference sets in rheumatoid arthritis treated with abatacept, rituximab, tocilizumab, or tumour necrosis factor inhibitors: a prospective cohort study from southern Sweden

Enzyme-linked immunosorbent assays for monitoring TNF-alpha inhibitors and antibody levels in people with rheumatoid arthritis: a systematic review and economic evaluation

BACKGROUND

Rheumatoid arthritis is a chronic autoimmune disease that primarily causes inflammation, pain and stiffness in the joints. People with severe disease may be treated with biological disease-modifying anti-rheumatic drugs, including tumour necrosis factor-α inhibitors, but the efficacy of these drugs is hampered by the presence of anti-drug antibodies. Monitoring the response to these treatments typically involves clinical assessment using response criteria, such as Disease Activity Score in 28 joints or European League Against Rheumatism. Enzyme-linked immunosorbent assays can also be used to measure drug and antibody levels in the blood. These tests may inform whether or not adjustments to treatment are required or help clinicians to understand the reasons for treatment non-response or a loss of response.

METHODS

Systematic reviews were conducted to identify studies reporting on the clinical effectiveness and cost-effectiveness of using enzyme-linked immunosorbent assays to measure drug and anti-drug antibody levels to monitor the response to tumour necrosis factor-α inhibitors [adalimumab (Humira®; AbbVie, Inc., North Chicago, IL, USA), etanercept (Enbrel®; Pfizer, Inc., New York, NY, USA), infliximab (Remicade®, Merck Sharp & Dohme Limited, Hoddesdon, UK), certolizumab pegol (Cimzia®; UCB Pharma Limited, Slough, UK) and golimumab (Simponi®; Merck Sharp & Dohme Limited)] in people with rheumatoid arthritis who had either achieved treatment target (remission or low disease activity) or shown primary or secondary non-response to treatment. A range of bibliographic databases, including MEDLINE, EMBASE and CENTRAL (Cochrane Central Register of Controlled Trials), were searched from inception to November 2018. The risk of bias was assessed using the Cochrane ROBINS-1 (Risk Of Bias In Non-randomised Studies - of Interventions) tool for non-randomised studies, with adaptations as appropriate. Threshold and cost-utility analyses that were based on a decision tree model were conducted to estimate the economic outcomes of adding therapeutic drug monitoring to standard care. The costs and resource use were considered from the perspective of the NHS and Personal Social Services. No discounting was applied to the costs and effects owing to the short-term time horizon of 18 months that was adopted in the economic analysis. The impact on the results of variations in testing and treatment strategies was explored in numerous clinically plausible sensitivity analyses.

RESULTS

Two studies were identified: (1) a non-randomised controlled trial, INGEBIO, that compared standard care with therapeutic drug monitoring using Promonitor® assays [Progenika Biopharma SA (a Grifols-Progenika company), Derio, Spain] in Spanish patients receiving adalimumab who had achieved remission or low disease activity; and (2) a historical control study. The economic analyses were informed by INGEBIO. Different outcomes from INGEBIO produced inconsistent results in both threshold and cost-utility analyses. The cost-effectiveness of therapeutic drug monitoring varied, from the intervention being dominant to the incremental cost-effectiveness ratio of £164,009 per quality-adjusted life-year gained. However, when the frequency of testing was assumed to be once per year and the cost of phlebotomy appointments was excluded, therapeutic drug monitoring dominated standard care.

LIMITATIONS

There is limited relevant research evidence and much uncertainty about the clinical effectiveness and cost-effectiveness of using enzyme-linked immunosorbent assay-based testing for therapeutic drug monitoring in rheumatoid arthritis patients. INGEBIO had serious limitations in relation to the National Institute for Health and Care Excellence scope: only one-third of participants had rheumatoid arthritis, the analyses were mostly not by intention to treat and the follow-up was 18 months only. Moreover, the outcomes might not be generalisable to the NHS.

CONCLUSIONS

Based on the available evidence, no firm conclusions could be made about the cost-effectiveness of therapeutic drug monitoring in England and Wales.

FUTURE WORK

Further controlled trials are required to assess the impact of using enzyme-linked immunosorbent assays for monitoring the anti-tumour necrosis factors in people with rheumatoid arthritis.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42018105195.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 8. See the NIHR Journals Library website for further project information.

People in states worse than dead according to the EQ-5D UK value set: would they rather be dead?

Purpose

Quality-adjusted life years (QALYs) measure health by combining length and quality of life. QALYs constitute the effect side of incremental cost-effectiveness ratios, describing the results of health economic evaluations. The objectives of this study were to (1) investigate the prevalence of states worse than dead (SWD) when using the EuroQol-5D UK value set, and (2) to study to what extent SWDs are reasonable with a starting point in experience-based valuations of health states.

Methods

Data from a Swedish cross-sectional population survey were used. The survey was directed to 10,000 persons 65 years and older and its primary aim was to investigate the prevalence and consequences of chronic pain. The survey included questions reflecting life situation and well-being. Some of these were used in order to characterise people in SWD.

Results

SWD were found in 1.8% of the 6611 respondents. The prevalence of SWD increased with advancing age and was more common among women than men. The control questions used indicated that most of the persons being in SWD according to the EQ-5D UK value set most probably would not judge themselves to be in a SWD.

Conclusions

Though negative QALY-weights are not very common, they constitute a non-negligible part of health states in a Swedish population 65 years and older. Prevalence of SWD is higher among women than men and increases with age. From responses to other questions on well-being and life situation, there is reason to doubt the reasonableness of experience-based negative QALY-weights in many cases.

An Experience-Based Value Set for the EQ-5D-5L in Germany

OBJECTIVE

Valuation of health states provides a summary measure useful to health care decision makers. Results may depend on whether the currently experienced health state or a hypothetical health state is being evaluated. This study derives a value set for the EuroQoL Five-Dimensional Five-Level Questionnaire (EQ-5D-5L) by focusing on the individual's current experience.

DATA AND METHODS

Data include four pooled population surveys of the general German population in 2012-2015 (N = 8114). For valuation, a visual analogue scale (VAS) was used. Six specifications of a generalized linear model with binomial error distribution and constraint parameter estimation were analyzed. In each 1000 simulation runs, models were cross-validated after splitting the sample into an estimation part and a validation part. Predictive accuracy was measured by mean absolute error and sum of squared errors.

RESULTS

The models rendered a consistent set of parameters. With regard to predictive accuracy, the model considering all problem levels within the five dimensions and the highest problem level reached performed best overall.

DISCUSSION

Estimation proved to be feasible. Predictive accuracy exceeded that of a similar, experience-based value set for the EQ-5D-3L. Compared with a Dutch value set for the EQ-5D-5L derived for hypothetical health states, experienced values tended to be slightly lower for mild health states and substantially higher for severe health states. Clinical relevance and usefulness of the value set remain to be determined in future studies.

CONCLUSIONS

For decision makers who prioritize patient-relevant benefit, the experience-based value set provides a novel option to summarize health states, reflecting how health states experienced are valued in a population.

EQ-5D studies in musculoskeletal and connective tissue diseases in eight Central and Eastern European countries: a systematic literature review and meta-analysis

EQ-5D is becoming the preferred instrument to measure health-state utilities involved in health technology assessment. The objective of this study is to assess the state of EQ-5D research in musculoskeletal disorders in 8 Central and Eastern European countries and to provide a meta-analysis of EQ-5D index scores. Original research articles published in any language between Jan 2000 and Sept 2016 were included, if they reported any EQ-5D outcome from at least two musculoskeletal patients from Austria, Bulgaria, the Czech Republic, Hungary, Poland, Romania, Slovakia, or Slovenia. Risk of bias was assessed with the Cochrane Collaboration's tool. Twenty-nine articles (5992 patients) were included on rheumatoid arthritis (n = 7), osteoporosis (n = 5), chronic pain (n = 5), osteoarthritis (n = 4), ankylosing spondylitis (n = 2), psoriatic arthritis (n = 2), total hip replacement (n = 2), and scleroderma (n = 2). Low back pain was under-represented, while studies in neck pain, systemic lupus erythematosus, gout, and childhood disorders were lacking. EQ-5D index scores were reported in 24 studies, while the version of the instrument and the value-set was not specified in 41% and 46% of the articles, respectively. Meta-analysis was performed on 24 disease states involving 6876 observation points. Intervention effect was reported in 22 subgroups, out of which risk of bias was low in 41%. This review provides recommendations to improve reporting standards of EQ-5D results and highlights potential areas for future research. Coordinated research in conditions with greatest public health impact as well as a development of a regional value-set could provide locally relevant health-state utilities that are transferable among countries within the region.