Mapping of the DLQI scores to EQ-5D utility values using ordinal logistic regression

Alitretinoin versus phototherapy as the first-line treatment in adults with severe chronic hand eczema: the ALPHA RCT

Background

Hand eczema is common and a cause of morbidity and occupational disability. When education, irritant/contact allergen avoidance, moisturisation and topical corticosteroids are insufficient to control chronic hand eczema, ultraviolet therapy or systemic immune-modifying drugs are used. There is no treatment pathway generally accepted by UK dermatologists.

Primary objective

Compare alitretinoin and ultraviolet therapy as first-line therapy in terms of disease activity at 12 weeks post planned start of treatment.

Design

Prospective, multicentre, open-label, two-arm parallel group, adaptive randomised controlled trial with one planned interim analysis, and an economic evaluation.

Setting

UK secondary care dermatology outpatient clinics.

Participants

Patients with severe chronic hand eczema unresponsive to at least 4 weeks of treatment with potent topical corticosteroids.

Primary end point

Natural logarithm of the Hand Eczema Severity Index + 1, 12 weeks post planned start of treatment.

Randomisation

Participants randomised 1 : 1 by minimisation to alitretinoin or ultraviolet therapy for 12 to 24 weeks.

Blinding

Blinded primary end-point assessor.

Results

Intention-to-treat population: 441 (100.0%) participants; 220 (49.9%) alitretinoin and 221 (50.1%) ultraviolet therapy. At least one dose was received by 212 (96.4%) alitretinoin and 196 (88.7%) ultraviolet therapy participants.

Primary outcome

The unadjusted median (interquartile range) relative change in hand eczema severity index at 12 weeks was 30% (10-70%) of that at baseline for alitretinoin compared with 50% (20-100%) for ultraviolet therapy. There was a statistically significant benefit of alitretinoin compared with ultraviolet therapy at 12 weeks, with an estimated fold change or relative difference (95% confidence interval) = 0.66 (0.52 to 0.82), p = 0.0003 at 12 weeks. There was no evidence of a difference at 24 or 52 weeks, with the estimated fold change (95% confidence interval) equal to 0.92 (0.798 to 1.08) and 1.27 (0.97 to 1.67), respectively.

Primary analysis results were consistent for secondary end points

Fifty-nine per cent allocated to alitretinoin and 61% allocated to ultraviolet therapy achieved a clear/almost clear assessment during the trial period. Differential treatment compliance observed: 145 (65.9%) alitretinoin and 53 (24.0%) ultraviolet therapy participants confirmed compliance (≥ 80% received, no treatment breaks > 7 days during first 12 weeks). High levels of missing data were observed.

Safety

One hundred and thirty-five reportable adverse events across 79 participants, 55 (25.0%) alitretinoin and 24 (10.9%) ultraviolet therapy. Four serious adverse events (two alitretinoin, two ultraviolet therapy). Four pregnancies reported (three alitretinoin, one ultraviolet therapy). No new safety signals were detected.

Conclusion

As a first-line therapy, alitretinoin showed more rapid improvement and superiority to ultraviolet therapy at week 12. This difference was not observed at later time points. Alitretinoin is cost-effective at weeks 12 and 52. Ultraviolet therapy is cost-effective after 10 years, with a high degree of uncertainty. Hand eczema severity index may be a useful primary outcome measure for hand eczema trials; ALPHA results will inform future trials.

Limitations

Treatment compliance was poor for ultraviolet therapy. Regular twice weekly treatment was not received by most patients. Assessment of long-term effects of randomised treatments was complicated by use of second-line treatments post treatment phase.

Further work

Further analysis of substudies and pilot data will provide valuable information for future studies. A clear need for better therapeutic approaches for severe chronic hand eczema remains. Future studies will need to further address long-term benefits of treatments given.

Trial registration

This trial is registered as ISRCTN80206075.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 12/186/01) and is published in full in Health Technology Assessment; Vol. 28, No. 59. See the NIHR Funding and Awards website for further award information.

Mapping Kansas City cardiomyopathy, Seattle Angina, and minnesota living with heart failure to the MacNew-7D in patients with heart disease

INTRODUCTION

The Kansas City Cardiomyopathy Questionnaire (KCCQ), Seattle Angina Questionnaire (SAQ), and Minnesota Living with Heart Failure Questionnaire (MLHFQ) are widely used non-preference-based instruments that measure health-related quality of life (QOL) in people with heart disease. However, currently it is not possible to estimate quality-adjusted life-years (QALYs) for economic evaluation using these instruments as the summary scores produced are not preference-based. The MacNew-7D is a heart disease-specific preference-based instrument. This study provides different mapping algorithms for allocating utility scores to KCCQ, MLHFQ, and SAQ from MacNew-7D to calculate QALYs for economic evaluations.

METHODS

The study included 493 participants with heart failure or angina who completed the KCCQ, MLHFQ, SAQ, and MacNew-7D questionnaires. Regression techniques, namely, Gamma Generalized Linear Model (GLM), Bayesian GLM, Linear regression with stepwise selection and Random Forest were used to develop direct mapping algorithms. Cross-validation was employed due to the absence of an external validation dataset. The study followed the Mapping onto Preference-based measures reporting Standards checklist.

RESULTS

The best models to predict MacNew-7D utility scores were determined using KCCQ, MLHFQ, and SAQ item and domain scores. Random Forest performed well for item scores for all questionnaires and domain score for KCCQ, while Bayesian GLM and Linear Regression were best for MLHFQ and SAQ domain scores. However, models tended to over-predict severe health states.

CONCLUSION

The three cardiac-specific non-preference-based QOL instruments can be mapped onto MacNew-7D utilities with good predictive accuracy using both direct response mapping techniques. The reported mapping algorithms may facilitate estimation of health utility for economic evaluations that have used these QOL instruments.

Mapping of Family Reported Outcome Measure (FROM-16) scores to EQ-5D: algorithm to calculate utility values

OBJECTIVE

Although decision scientists and health economists encourage inclusion of family member/informal carer utility in health economic evaluation, there is a lack of suitable utility measures comparable to patient utility measures such those based on the EQ-5D. This study aims to predict EQ-5D-3L utility values from Family Reported Outcome Measure (FROM-16) scores, to allow the use of FROM-16 data in health economic evaluation when EQ-5D data is not available.

METHODS

Data from 4228 family members/partners of patients recruited to an online cross-sectional study through 58 UK-based patient support groups, three research support platforms and Welsh social services departments were randomly divided five times into two groups, to derive and test a mapping model. Split-half cross-validation was employed, resulting in a total of ten multinomial logistic regression models. The Monte Carlo simulation procedure was used to generate predicted EQ-5D-3L responses, and utility scores were calculated and compared against observed values. Mean error and mean absolute error were calculated for all ten validation models. The final model algorithm was derived using the entire sample.

RESULTS

The model was highly predictive, and its repeated fitting using multinomial logistic regression demonstrated a stable model. The mean differences between predicted and observed health utility estimates ranged from 0.005 to 0.029 across the ten modelling exercises, with an average overall difference of 0.015 (a 2.2% overestimate, not of clinical importance).

CONCLUSIONS

The algorithm developed will enable researchers and decision scientists to calculate EQ-5D health utility estimates from FROM-16 scores, thus allowing the inclusion of the family impact of disease in health economic evaluation of medical interventions when EQ-5D data is not available.

How to use the Harmonising Outcome Measures for Eczema Core Outcome Set for atopic dermatitis trials: a users' guide

BACKGROUND

The Harmonising Outcome Measures for Eczema (HOME) initiative has agreed upon the Core Outcome Set (COS) for use in atopic dermatitis (AD) clinical trials, but additional guidance is needed to maximize its uptake.

OBJECTIVES

To provide answers to some of the commonly asked questions about using the HOME COS; to provide data to help with the interpretation of trial results; and to support sample size calculations for future trials.

METHODS AND RESULTS

We provide practical guidance on the use of the HOME COS for investigators planning clinical trials in patients with AD. It answers some of the common questions about using the HOME COS, how to access the outcome measurement instruments, what training/resources are needed to use them appropriately and clarifies when the COS is applicable. We also provide exemplar data to inform sample size calculations for eczema trials and encourage standardized data collection and reporting of the COS.

CONCLUSIONS

By encouraging adoption of the COS and facilitating consistent reporting of outcome data, it is hoped that the results of eczema trials will be more comprehensive and readily combined in meta-analyses and that patient care will subsequently be improved.

Development of algorithms to estimate the EQ-5D-5L from the FACT-L in patients with lung cancer: a mapping study

OBJECTIVE

This study aimed to develop a mapping algorithm to evaluate the EQ-5D-5L according to the FACT-L when the EQ-5D-5L is not available.

METHODS

EQ-5D-5L and FACT-L data were collected from patients with lung cancer in Departments of Thoracic Surgery, Medical Oncology, Radiation Oncology, Sichuan Cancer Hospital. We used the ordinary least squares model (OLS), Tobit model (Tobit), two-part model (TPM), beta mixture regression (BM), and censored least absolute deviation model (CLAD) to map the results of the FACT-L according to EQ-5D-5L scores. To establish these models, the total score, dimension scores, squared items, and interaction items were introduced. Performance metrics including Adjusted R2, root mean square error (RMSE), and mean absolute error (MAE) were used to select the optimized model.

RESULTS

The model with the best mapping performance was the BM model (BETAMIX4) with the PWB (physical well-being) dimension, FWB (functional well-being) dimension, the squared term of the PWB dimension, and the squared term of the FWB dimension as covariates. The final prediction metrics were Adjusted R2 = 0.695, RMSE = 0.206, and MAE = 0.109. Fivefold cross-validation (CV) results also demonstrated that the BM model had the best mapping power.

CONCLUSIONS

This study developed an optimized mapping algorithm to predict the utility index from the FACT-L to the EQ-5D-5L, which provides an effective alternative reference for EQ-5D-5L estimation when the preference-based health utility values were unavailable.

A center-based, ambulatory care concept for hidradenitis suppurativa improves patient outcomes and is also cost-effectiveness

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease affecting approximately 1% of the population. The patient journey through the German health care system leads to high disease burden and substantial treatment costs. The EsmAiL study showed that an innovative, interprofessional, multimodal care-concept reduces disease activity and burden of HS compared to standard care. This paper examines the costs of treating HS in Germany and compares them with those of the innovative care concept implemented in EsmAiL.

METHODS

EsmAiL was a two-arm, multicenter, prospective randomized controlled trial including 553 adults with HS. The study was registered in the German Clinical Trials Registry (DRKS00022135). The control group (CG) remained in standard care, whereas the intervention group (IG) was referred to specialized so-called 'acne-inversa-centres (AiZ)' where patients were treated with a structured, interdisciplinary approach. The present paper analyses the treatment costs for a subpopulation based on health insurance cost data from the two largest German health insurers. Quality-Adjusted Life Years (QALY) was assessed based on Dermatology Life Quality Index (DLQI).

RESULTS

Total annual treatment costs per patient were €3,966.07 in standard care (n = 89) and €3,974.37 in the innovative care (n = 93). The costs per additional QALY amounted to €12,698.72 in the IG. Given the conventional and established threshold of €22,600 to €33,900 per QALY, the innovative treatment in AiZ proved to be cost-effective.

CONCLUSION

Treatment costs of HS are substantial and increase with disease severity. The new form of care is cost-effective and is expected to decrease costs in the long run.

Cost-Effectiveness of Secukinumab Versus Other Biologics in the Treatment of Moderate-to-Severe Plaque Psoriasis: The Chinese Healthcare System Perspective

INTRODUCTION

This study assessed the cost-effectiveness of secukinumab compared with other biologics (adalimumab, infliximab, ustekinumab, ixekizumab, guselkumab, and Yisaipu [etanercept biosimilar]) for moderate-to-severe plaque psoriasis from the Chinese healthcare system perspective.

METHODS

A decision-tree (first year)/Markov model (subsequent years), with an annual cycle, was implemented over a lifetime horizon. The Psoriasis Area and Severity Index (PASI) response rate at week 16 was used for treatment response. Efficacy inputs were obtained from a mixed-treatment comparison conducted using data from randomized controlled trials. Other clinical inputs (adverse events, dropout, and mortality rates), utility weights, and costs were derived from published literature and local Chinese sources. Both costs and outcomes were discounted at 5% per annum. Model outcomes included quality-adjusted life years (QALYs) and incremental cost-effectiveness ratio (ICER). One-way and probabilistic sensitivity analyses were conducted to test the robustness of results.

RESULTS

For patients with moderate-to-severe psoriasis, secukinumab generated the highest QALYs (12.334) against all comparators at a lifetime cost of ¥231,477. Secukinumab dominated (higher QALYs at lower costs) all other biologics except ixekizumab in this population. Compared with secukinumab, ixekizumab incurred slightly lower costs (¥228,320) but gained lesser QALYs (12.284). Thus, secukinumab was a cost-effective treatment than ixekizumab at a willingness-to-pay (WTP) threshold of ¥257,094 per QALY gained. In the one-way sensitivity analysis, base-case results were most sensitive to changes in the PASI response at 16 weeks and year 2+ dropout rates.

CONCLUSION

Secukinumab is the most cost-effective treatment option for patients with moderate-to-severe psoriasis compared with other commonly used biologics from the Chinese healthcare system perspective.

Estimating health related quality of life effects in vitiligo. Mapping EQ-5D-5 L utilities from vitiligo specific scales: VNS, VitiQoL and re-pigmentation measures using data from the HI-Light trial

BACKGROUND

Vitiligo is reported to affect 2% of the world's population and has a significant impact on health related quality of life (HRQoL). The relationship between HRQoL and clinical outcomes used in vitiligo require further examination. Mapping condition specific measures of HRQoL: vitiligo specific quality of life instrument (VitiQoL), vitiligo noticeability scale (VNS) and vitiligo re-pigmentation scores (RPS) to the EQ-5D have not yet been reported.

METHODS

Data collected from a randomised clinical trial (HI-Light) in vitiligo was used to develop mapping algorithms for the EQ-5D-5 L and the relationship between HRQoL, clinical outcomes and EQ-5D were investigated. Two EQ-5D-5 L value sets (Van Hout and Alava) using linear and non-linear models were considered. Logistic regression models were used to model the probability of vitiligo noticeability (VNS) in terms of RPS, EQ-5D and VitiQoL scores.

RESULTS

Mapping from RPS appeared to perform better followed by VNS for the Alava crosswalks using polynomial models: Mean observed vs. predicted utilities of 0.9008 (0.005) vs. 0.8984 (0.0004) were observed for RPS. For VNS, mean observed vs. predicted utilities of 0.9008 (0.005) vs. 0.8939 (0.0003) were observed. For VitiQoL, mean observed vs. predicted utilities of 0.9008 (0.005) vs. 0.8912 (0.0002) were observed. For patients with the least re-pigmentation (RPS < 25%), a Total VitiQoL score of about 20 points gives around an 18% chance of vitiligo being no longer or a lot less noticeable.

CONCLUSION

The algorithm based on RPS followed by VNS performed best. The relationship between effects from vitiligo specific HRQoL instruments and clinical RPS was established allowing for plausible clinically relevant differences to be identified, although further work is required in this area.

Mapping of disease-specific Oxford Knee Score onto EQ-5D-5L utility index in knee osteoarthritis

BACKGROUND

EQ5D is a generic measure of health. It provides a single index value for health status that can be used in the clinical and economic evaluation of healthcare. Oxford Knee Score (OKS) is a joint-specific outcome measure tool designed to assess symptoms and function in osteoarthritis patients after joint replacement surgery. Though widely used, it has the disadvantage of lacking health index value. To fill the gap between functional and generic questionnaires with economic value, we linked generic EQ-5D-5L to the specific OKS to give a single index value for health status in KOA patients.

QUESTIONS/PURPOSES

Developing and evaluating an algorithm to estimate EuroQoL generic health utility scores (EQ-5D-5L) from the disease-specific OKS using data from patients with knee osteoarthritis (KO).

PATIENTS AND METHODS

This is a cross-sectional study of 571 patients with KO. We used four distinct mapping algorithms: Cumulative Probability for Ordinal Data, Penalized Ordinal Regression, CART (Classification and Regression Trees), and Ordinal random forest. We compared the resultant models' degrees of accuracy.

RESULTS

Mobility was best predicted by penalized regression with pre-processed predictors, usual activities by random forest, pain/discomfort by cumulative probability with pre-processed predictors, self-care by random forest with RFE (recursive feature elimination) predictors, and anxiety/depression by CART with RFE predictors. Model accuracy was lowest with anxiety/depression and highest with mobility and usual activities. Using available country value sets, the average MAE was 0.098 ± 0.022, ranging from 0.063 to 0.142; and the average MSE was 0.020 ± 0.008 ranging from 0.008 to 0.042.

CONCLUSIONS

The current study derived accurate mapping techniques from OKS to the domains of EQ-5D-5L, allowing for the computation of QALYs in economic evaluations. A machine learning-based strategy offers a viable mapping alternative that merits further exploration.

Assessment of health state utilities in dermatology: an experimental time trade-off value set for the dermatology life quality index

Background

Dermatology Life Quality Index (DLQI) scores are used in many countries as access and reimbursement criteria for costly dermatological treatments. In this study we examined how time trade-off (TTO) utility valuations made by individuals from the general population are related to combinations of DLQI severity levels characterizing dermatologically relevant health states, with the ultimate purpose of developing a value set for the DLQI.

Methods

We used data from an online cross-sectional survey conducted in Hungary in 2020 (n = 842 after sample exclusions). Respondents were assigned to one of 18 random blocks and were asked to provide 10-year TTO valuations for the corresponding five hypothetical health states. To analyze the relationship between DLQI severity levels and utility valuations, we estimated linear, censored, ordinal, and beta regression models, complemented by two-part scalable models accommodating heterogeneity effects in respondents’ valuation scale usage. Successive severity levels (0–3) of each DLQI item were represented by dummy variables. We used cross-validation methods to reduce the initial set of 30 dummy variables and improve model robustness.

Results

Our final, censored linear regression model with 13 dummy variables had R² = 0.136, thus accounting for 36.9% of the incremental explanatory power of a maximal (full-information) benchmark model (R² = 0.148) over the uni-dimensional model (R² = 0.129). Each DLQI item was found to have a negative effect on the valuation of health states, yet this effect was largely heterogeneous across DLQI items, and the relative contribution of distinctive severity levels also varied substantially. Overall, we found that the social/interpersonal consequences of skin conditions (in the areas of social and leisure activities, work and school, close personal relationships, and sexuality) had roughly twice as large disutility impact as the physical/practical aspects.

Conclusions

We have developed an experimental value set for the DLQI, which could prospectively be used for quantifying the quality-adjusted life years impact of dermatological treatments and serve as a basis for cost-effectiveness analyses. We suggest that, after validation of our main results through confirmatory studies, population-specific DLQI value sets could be developed and used for conducting cost-effectiveness analyses and developing financing guidelines in dermatological care.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12955-022-01995-x.

Comparison of ALitretinoin with PUVA as the first-line treatment in patients with severe chronic HAnd eczema (ALPHA): study protocol for a randomised controlled trial

INTRODUCTION

Hand eczema (HE) is one of the most common skin disorders and an important cause for morbidity and occupational disability. The 1-year prevalence of HE is estimated to be up to 10% and it is estimated that 5%-7% of those develop severe chronic HE. However, current clinical evidence is not compelling enough to guide clinical practice. In a survey among 194 UK dermatologists the most frequent first choice approaches were psoralen combined with ultraviolet A (UVA) treatment (PUVA), oral steroids and alitretinoin (AL). When asked which strategy was most efficient for long-term outcome 20% of clinicians indicated they did not know; 43% of clinicians reported AL and 30% reported PUVA.

METHODS AND ANALYSIS

ALPHA is a multicentre, open, prospective, two-arm parallel group, randomised controlled trial comparing PUVA and AL with a planned sample size re-estimation. Between 500 and 780 participants will be randomised on a 1:1 basis. The physician's global assessment (PGA) will direct treatment after randomisation, non-responders will be treated according to usual clinical practice; providing valuable pilot data on second line therapeutic approaches to inform future trials.Assessments will be conducted up to 52 weeks post randomisation. The primary outcome measure is the Hand Eczema Severity Index at 12 weeks. Secondary outcome measures include modified Total Lesion Symptom Score, PGA, time to relapse, patient reported outcome measures and DNA extraction and assessment of genetic variants. A substudy on molecular inflammatory mediators will provide information on subgroup specific treatment responses. Photographs will be taken and HE severity assessed by a central review panel.

ETHICS AND DISSEMINATION

Ethics approval was obtained from Leeds West Research Ethics Committee (14/YH/1259).Trial results will be disseminated at relevant clinical conferences and societies, published in peer-reviewed journals and through relevant patient groups.

TRIAL REGISTRATION NUMBER

ISRCTN80206075.

Health utilities for non-melanoma skin cancers and pre-cancerous lesions: A systematic review

BACKGROUND

Non-melanoma skin cancers (NMSCs) are common and consume many healthcare resources. A health utility is a single preference-based value for assessing health-related quality of life, which can be used in economic evaluations. There are scarce data on health utilities for NMSCs.

OBJECTIVES

Using a systematic review approach, we synthesized the current data on NMSC-related health utilities.

METHODS

A systematic review of studies of NMSC-related health utilities was conducted in Medline, Embase, and Cochrane databases. Data were extracted based on the protocol and a quality assessment was performed for each study.

RESULTS

The protocol resulted in 16 studies, involving 121 621 participants. Mean utility values across the studies ranged from 0.56 to 1 for undifferentiated NMSC, 0.84 to 1 for actinic keratosis, 0.45 to 1 for squamous cell carcinoma, and 0.67 to 1 for basal cell carcinoma. There was considerable variability in utilities by type of cancer, stage of diagnosis, time to treatment, treatment modality, and quality of life instrument or method. Utility values were predominantly based on the EuroQol 5-dimension instrument and ranged from 0.45 to 0.96, while other measurement methods produced values ranging from 0.67 to 1. Lower utility values were observed for advanced cancers and for the time period during and immediately after treatment, after which values gradually returned to pre-treatment levels.

CONCLUSIONS

Most utility values clustered around relatively high values of 0.8 to 1, suggesting small decrements in quality of life associated with most NMSCs and their precursors. Variability in utilities indicates that careful characterization is required for measures to be used in economic evaluations.

Health-related quality of life impact of scabies in the Solomon Islands

Background

Scabies causes intense itching and skin lesions. A small number of studies have shown that scabies impacts health-related quality of life (HRQoL), but no studies have been conducted in the Pacific region. We assessed the impact of scabies on HRQoL in a high-prevalence setting using the Children's Dermatology Life Quality Index (CDLQI) and Dermatology Life Quality Index (DLQI). We also assessed the validity of these tools in a Pacific Island population.

Methods

The study was conducted in the Solomon Islands. Participants with and without skin disease were randomly selected. HRQoL indices were scored on a scale of 0–30.

Results

We surveyed 1051 adults (91 with scabies) and 604 children (103 with scabies). Scabies had a small impact on HRQoL, with a median DLQI score of 2 (interquartile range [IQR] 0–6) and a CDLQI score of 2 (IQR 0–4). Scores increased linearly with severity. The greatest impact on QoL was due to itch, sleep disturbance and impacts on education and employment.

Conclusions

Scabies has a small but measurable impact on HRQoL. The DLQI and CDLQI scores were discriminated between the skin-related QoL of patients with scabies and the control group, indicating that these tools are appropriate to measure skin-related QoL in the Solomon Islands.

Predicting EQ-5D-5L crosswalk from the PROMIS-29 profile for the United Kingdom, France, and Germany

Background

EQ-5D health state utilities (HSU) are commonly used in health economics to compute quality-adjusted life years (QALYs). The EQ-5D, which is country-specific, can be derived directly or by mapping from self-reported health-related quality of life (HRQoL) scales such as the PROMIS-29 profile. The PROMIS-29 from the Patient Reported Outcome Measures Information System is a comprehensive assessment of self-reported health with excellent psychometric properties. We sought to find optimal models predicting the EQ-5D-5L crosswalk from the PROMIS-29 in the United Kingdom, France, and Germany and compared the prediction performances with that of a US model.

Methods

We collected EQ-5D-5L and PROMIS-29 profiles and three samples representative of the general populations in the UK (n = 1509), France (n = 1501), and Germany (n = 1502). We used stepwise regression with backward selection to find the best models to predict the EQ-5D-5L crosswalk from all seven PROMIS-29 domains. We investigated the agreement between the observed and predicted EQ-5D-5L crosswalk in all three countries using various indices for the prediction performance, including Bland–Altman plots to examine the performance along the HSU continuum.

Results

The EQ-5D-5L crosswalk was best predicted in France (nRMSE_FRA = 0.075, nMAE_FRA = 0.052), followed by the UK (nRMSE_UK = 0.076, nMAE_UK = 0.053) and Germany (nRMSE_GER = 0.079, nMAE_GER = 0.051). The Bland–Altman plots show that the inclusion of higher-order effects reduced the overprediction of low HSU scores.

Conclusions

Our models provide a valid method to predict the EQ-5D-5L crosswalk from the PROMIS-29 for the UK, France, and Germany.

Mapping Dermatology Life Quality Index (DLQI) scores to EQ-5D utility scores using data of patients with atopic dermatitis from the National Health and Wellness Study

PURPOSE

To develop a mapping algorithm for generating EQ-5D-5-level (EQ-5D-5L) utility scores from the Dermatology Life Quality Index (DLQI) in patients with atopic dermatitis (AD).

METHODS

The algorithm was developed using data from 1232 patients from four countries participating in the National Health and Wellness Study. Spearman's rank correlation coefficient was used to evaluate the conceptual overlap between DLQI and EQ-5D-5L. Six mapping models (ordinary least squares [OLS], Tobit, three different two-part models, and a regression mixture model) were tested with different specifications to determine model performance and were ranked based on the sum of mean absolute error (MAE), and root mean squared error (RMSE).

RESULTS

The mean DLQI score was 7.23; mean EQ-5D-5L score was 0.78; and there were moderate negative correlations between DLQI and EQ-5D-5L scores (p = - 0.514). A regression mixture model with total DLQI, and age and sex as independent variables performed best for mapping DLQI to EQ-5D-5L (RMSE = 0.113; MAE = 0.079).

CONCLUSION

This was the first study to map DLQI to EQ-5D-5L exclusively in patients with AD. The regression mixture model with total DLQI, and age and sex as independent variables was the best performing model and accurately predicted EQ-5D-5L. The results of this mapping can be used to translate DLQI data from clinical studies to health state utility values in economic evaluations.

'Mapping' Health State Utility Values from Non-preference-Based Measures: A Systematic Literature Review in Rare Diseases

BACKGROUND

The use of patient-reported outcome measures (PROMs) to monitor the effects of disease and treatment on patient symptomatology and daily life is increasing in rare diseases (RDs) (i.e. those affecting less than one in 2000 people); however, these instruments seldom yield health state utility values (HSUVs) for cost-utility analyses. In such a context, 'mapping' allows HSUVs to be obtained by establishing a statistical relationship between a 'source' (e.g. a disease-specific PROM) and a 'target' preference-based measure [e.g. the EuroQol-5 Dimension (EQ-5D) tool].

OBJECTIVE

This study aimed to systematically review all published studies using 'mapping' to derive HSUVs from non-preference-based measures in RDs, and identify any critical issues related to the main features of RDs, which are characterised by small, heterogeneous, and geographically dispersed patient populations.

METHODS

The following databases were searched during the first half of 2019 without time, study design, or language restrictions: MEDLINE (via PubMed), the School of Health and Related Research Health Utility Database (ScHARRHUD), and the Health Economics Research Centre (HERC) database of mapping studies (version 7.0). The keywords combined terms related to 'mapping' with Orphanet's list of RD indications (e.g. 'acromegaly') in addition to 'rare' and 'orphan'. 'Very rare' diseases (i.e. those with fewer than 1000 cases or families documented in the medical literature) were excluded from the searches. A predefined, pilot-tested extraction template (in Excel^®) was used to collect structured information from the studies.

RESULTS

Two groups of studies were identified in the review. The first group (n = 19) developed novel mapping algorithms in 13 different RDs. As a target measure, the majority used EQ-5D, and the others used the Short-Form Six-Dimension (SF-6D) and 15D; most studies adopted ordinary least squares (OLS) regression. The second group of studies (n = 9) applied previously published algorithms in non-RDs to comparable RDs, mainly in the field of cancer. The critical issues relating to 'mapping' in RDs included the availability of very few studies, the relatively high number of cancer studies, and the absence of research in paediatric RDs. Moreover, the reviewed studies recruited small samples, showed a limited overlap between RD-specific and generic PROMs, and highlighted the presence of cultural and linguistic factors influencing results in multi-country studies. Lastly, the application of existing algorithms developed in non-RDs tended to produce inaccuracies at the bottom of the EQ-5D scale, due to the greater severity of RDs.

CONCLUSIONS

More research is encouraged to develop algorithms for a broader spectrum of RDs (including those affecting young children), improve mapping study quality, test the generalisability of algorithms developed in non-RDs (e.g. HIV) to rare variants or evolutions of the same condition (e.g. AIDS wasting syndrome), and verify the robustness of results when mapped HSUVs are used in cost-utility models.

Development of algorithms to estimate EQ-5D and derive health utilities from WHOQOL-HIV Bref: a mapping study

PURPOSE

This study aimed to develop and evaluate different families of applicable models available for utility mapping between World Health Organization Quality of Life for HIV-abbreviated version (WHOQOL-HIV Bref) and EQ-5D-3L and to propose an optimised algorithm to estimate health utilities of people living with HIV.

METHODS

Estimation dataset was collected between July 2014 and September 2016 in a cross-sectional study including 1526 people living with HIV/Aids (PLWH) under care at the Instituto Nacional de Infectologia Evandro Chagas-FIOCRUZ, in Brazil. Data of WHOQOL-HIV Bref and EQ-5D-3L questionnaires were collected. Fisher's exact tests were used for testing WHOQOL-HIV Bref response frequencies among groups of responses to each of the five EQ-5D-3L domains. Multiple correspondence analyses (MCA) were used to inspect the relationships between both instrument responses. Different families of applicable models available for utility mapping between WHOQOL-HIV Bref and EQ-5D-3L were adjusted for the prediction of disutility.

RESULTS

Candidate models' performances using mean absolute error (MAE), mean squared error (MSE), and root mean squared error (RMSE) were similarly good, which was evidenced by the overlapping of its 95% confidence intervals of the mean tenfold cross-validation or estimated generalisation errors. However, the Hurdle Logistic-Log-Normal model was better on average according to generalisation errors both in the prediction of Brazilian utility values (MAE = 0.1037, MSE = 0.0178, and RMSE = 0.1332) and for those of the UK (MAE = 0.1476, MSE = 0.0443, and RMSE = 0.2099).

CONCLUSIONS

Mapping EQ-5D-3L responses or deriving health utilities directly from WHOQOL-HIV Bref responses can be a valid alternative for settings with no preference-based health utility data.

Mapping function from FACT-B to EQ-5D-5 L using multiple modelling approaches: data from breast cancer patients in China

BACKGROUND

The Functional Assessment of Cancer Therapy-Breast (FACT-B) is the most commonly used scale for assessing quality of life in patients with breast cancer. The lack of preference-based measures limits the cost-utility of breast cancer in China. The goal of this study was to explore whether a mapping function can be established from the FACT-B to the EQ-5D-5 L when the EQ-5D health-utility index is not available.

METHODS

A cross-sectional survey of adults with breast cancer was conducted in China. All patients included in the study completed the EQ-5D-5 L and the disease-specific FACT-B questionnaire, and demographic and clinical data were also collected. The Chinese tariff value was used to calculate the EQ-5D-5 L utility scores. Five models were evaluated using three different modelling approaches: the ordinary least squares (OLS) model, the Tobit model and the two-part model (TPM). Total scores, domain scores, squared terms and interaction terms were introduced into models. The goodness of fit, signs of the estimated coefficients, and normality of prediction errors of the model were also assessed. The normality of the prediction error is determined by calculating the root mean squared error (RMSE), the mean absolute deviation (MAD), and the mean absolute error (MAE). Akaike information criteria (AIC) and Bayes information criteria (BIC) were also used to assess models and predictive performances. The OLS model was followed by simple linear equating to avoid regression to the mean.

RESULTS

The performance of the models was improved after the introduction of the squared terms and the interaction terms. The OLS model, including the squared terms and the interaction terms, performed best for mapping the EQ-5D-5 L. The explanatory power of the OLS model was 70.0%. The AIC and BIC of this model were the smallest (AIC = -705.106, BIC = -643.601). The RMSE, MAD and MAE of the OLS model, Tobit model and TPM were similar. The MAE values of the 5-fold cross-validation of the multiple models in this study were 0.07155~0.08509; meanwhile, the MAE of the TPM was the smallest, followed by that of the OLS model. The OLS regression proved to be the most accurate for the mean, and linearly equated scores were much closer to observed scores.

CONCLUSIONS

This study establishes a mapping algorithm based on the Chinese population to estimate the EQ-5D-5 L index of the FACT-B and confirms that OLS models have higher explanatory power and that TPMs have lower prediction error. Given the accuracy of the mean prediction and the simplicity of the model, we recommend using the OLS model. The algorithm can be used to calculate EQ-5D scores when EQ-5D data are not directly collected in a study.

Quality of life and psychological impact in the photodermatoses: a systematic review

BACKGROUND

The photodermatoses affect large proportions of the population but their impact on quality of life (QoL) and psychological health has not been reviewed. Several tools are available to evaluate QoL and psychological impacts.

OBJECTIVES

To systematically review current literature to identify tools used to assess QoL and psychological impacts in patients with photodermatoses, and to summarize the reported findings.

METHODS

A systematic search of PubMed, OVID Medline, PsycInfo and CINAHL was performed for articles investigating QoL and/or psychological impact in patients with photodermatoses, published between 1960 and September 2018.

RESULTS

Twenty studies were included: 19 incorporated QoL assessment while three evaluated psychological morbidity. Six QoL tools were found to be used: Dermatology Life Quality Index (DLQI), Children's DLQI, Family DLQI, Skindex (16- and 29-item versions), Erythropoietic Protoporphyria Quality of Life (EPP-QoL) and EuroQol. Between 31% and 39% of photosensitive patients reported a very large impact on QoL (DLQI > 10). Employment and education, social and leisure activities, and clothing choices were particularly affected. Only one tool was specifically designed for a photodermatosis (EPP-QoL). Four tools were used to evaluate psychological impact: the Hospital Anxiety and Depression Scale, Fear of Negative Evaluation, brief COPE and Illness Perception Questionnaire-Revised. Levels of anxiety and depression were approximately double British population data. Patients with facial involvement, female gender and younger age at onset showed more psychological morbidity.

CONCLUSIONS

Several tools have been used to assess QoL in the photodermatoses, and confirm substantial impact on QoL. Development of specific, validated QoL measures would address their unique impacts. Research delineating their psychological comorbidity is sparse and requires further exploration. What's already known about this topic? The photodermatoses negatively impact quality of life (QoL) and cause psychological distress, but no reviews of this area appear in the literature. What does this study add? Few studies have explored the psychological and social impacts of the photodermatoses. There are no fully validated QoL tools specific to the photodermatoses. Around one-third of adult and child patients with photosensitivity experience very or extremely large impact on QoL, with particular effect on clothing choices, employment and social and leisure activities. Studies suggest anxiety and depression levels in these patients are around double those in the U.K. general population. More attention is required on these 'hidden' conditions.

An Updated Systematic Review of Studies Mapping (or Cross-Walking) Measures of Health-Related Quality of Life to Generic Preference-Based Measures to Generate Utility Values

BACKGROUND

Mapping is an increasingly common method used to predict instrument-specific preference-based health-state utility values (HSUVs) from data obtained from another health-related quality of life (HRQoL) measure. There have been several methodological developments in this area since a previous review up to 2007.

OBJECTIVE

To provide an updated review of all mapping studies that map from HRQoL measures to target generic preference-based measures (EQ-5D measures, SF-6D, HUI measures, QWB, AQoL measures, 15D/16D/17D, CHU-9D) published from January 2007 to October 2018.

DATA SOURCES

A systematic review of English language articles using a variety of approaches: searching electronic and utilities databases, citation searching, targeted journal and website searches.

STUDY SELECTION

Full papers of studies that mapped from one health measure to a target preference-based measure using formal statistical regression techniques.

DATA EXTRACTION

Undertaken by four authors using predefined data fields including measures, data used, econometric models and assessment of predictive ability.

RESULTS

There were 180 papers with 233 mapping functions in total. Mapping functions were generated to obtain EQ-5D-3L/EQ-5D-5L-EQ-5D-Y (n = 147), SF-6D (n = 45), AQoL-4D/AQoL-8D (n = 12), HUI2/HUI3 (n = 13), 15D (n = 8) CHU-9D (n = 4) and QWB-SA (n = 4) HSUVs. A large number of different regression methods were used with ordinary least squares (OLS) still being the most common approach (used ≥ 75% times within each preference-based measure). The majority of studies assessed the predictive ability of the mapping functions using mean absolute or root mean squared errors (n = 192, 82%), but this was lower when considering errors across different categories of severity (n = 92, 39%) and plots of predictions (n = 120, 52%).

CONCLUSIONS

The last 10 years has seen a substantial increase in the number of mapping studies and some evidence of advancement in methods with consideration of models beyond OLS and greater reporting of predictive ability of mapping functions.

Using machine-learning approaches to predict non-participation in a nationwide general health check-up scheme

BACKGROUND

In the time since the launch of a nationwide general health check-up and instruction program in Japan in 2008, interest in the formulation of an effective and efficient strategy to improve the participation rate has been growing. The aim of this study was to develop and evaluate models identifying those who are unlikely to undergo general health check-ups. We used machine-learning methods to select interventional targets more efficiently.

METHODS

We used information from a local government database of Japan. The study population included 7290 individuals aged 40-74 years who underwent at least one general health check-up between 2012 and 2015. We developed four predictive models based on the extreme gradient boosting (XGBoost), random forest (RF), support vector machines (SVMs), and logistic regression (LR) algorithms, using machine-learning techniques, and compared the areas under the curves (AUCs) of the models with those of the heuristic method (which presumes that the individuals who underwent a general health check-up in the previous year will do so again in the following year).

RESULTS

The AUCs for the XGBoost, RF, SVMs, LR, and heuristic models/method were 0.829 (95% confidence interval [CI]: 0.806-0.853), 0.821 (95% CI: 0.797-0.845), 0.812 (95% CI: 0.787-0.837), 0.816 (95% CI: 0.791-0.841), and 0.683 (95% CI: 0.657-0.708), respectively. XGBoost model exhibited the best AUC, and the performance was significantly better than that of SVMs (p = 0.034), LR (p = 0.017), and heuristic method (p < 0.001). However, the performance of XGBoost did not differ significantly from that of RF (p = 0.229).

CONCLUSION

Predictive models using machine-learning techniques outperformed the existing heuristic method when used to predict participation in a general health check-up system by eligible participants.

Generating EQ-5D-3L Utility Scores from the Dermatology Life Quality Index: A Mapping Study in Patients with Psoriasis

OBJECTIVES

To develop an algorithm to predict the three-level EuroQol five-dimensional questionnaire (EQ-5D-3L) utility scores from the Dermatology Life Quality Index (DLQI) in psoriasis.

METHODS

This mapping study used data from the British Association of Dermatologists Biologic Interventions Register-a pharmacovigilance register comprising patients with moderate to severe psoriasis on systemic therapies. Conceptual overlap between the EQ-5D-3L and DLQI was assessed using Spearman rank correlation coefficients and exploratory factor analysis. Six regression methods to predict the EQ-5D-3L index (direct mapping) and two regression methods to predict EQ-5D-3L domain responses (response mapping) were tested. Random effects models were explored to account for repeated observations from the same individual. Estimated and actual EQ-5D-3L utility scores were compared using 10-fold cross-validation (in-sample) to evaluate predictive performance. Final models were selected using root mean squared error, mean absolute error, and mean error.

RESULTS

The data set comprised 22,085 observations for which DLQI and EQ-5D-3L were recorded on the same day. A moderate correlation was found between the measures (r = -0.47). Exploratory factor analysis showed that two EQ-5D-3L domains (pain/discomfort and depression/anxiety) were associated with all six DLQI domains. The best-performing model used ordinary least squares with DLQI items, age, and sex as explanatory variables (with squared, cubic, and interaction terms). A tool was produced to allow users to map their data to the EQ-5D-3L, and includes algorithms that require fewer variables (e.g., total DLQI scores).

CONCLUSIONS

This study produced mapping algorithms that can generate EQ-5D-3L utility scores from DLQI data for economic evaluations of health interventions for patients with psoriasis.