Valuation of multi-dimensional health states with a "bolt-on": is there a shortcut?

OBJECTIVES: In order to use the EQ-5D questionnaire with bolt-on dimensions in economic evaluation studies, new value sets are needed. In this study, we explored the feasibility of a new approach called scaling factor model, which estimates bolt-on value sets using estimated EQ-5D dimensional weights. METHODS: We designed a two-arm study, inviting university students to value health states with and without bolt-on items using the composite time trade-off (cTTO) method. We selected 25 health states from an orthogonal array and added 5 mildest EQ-5D states in the design. In arm 1, EQ-5D without self-care and standard EQ-5D states were valued, and in arm 2, standard EQ-5D states and EQ-5D with vision were valued. By arm, we compared the mean observed values of health states with and without bolt-on item. Next, by arm, we estimated value sets for the EQ-5D with bolt-on item states using both standard model and scaling factor model. Model performances were compared in terms of prediction accuracy and correlation with likelihood-based mean values. RESULTS: Adding a fifth-level bolt-on to EQ-5D resulted in statistically lower values. This effect is consistent across two arms and bolt-on items. The scaling factor models outperformed the standard models in all statistics. CONCLUSIONS: The scaling factor model offers a methodologically viable and low-cost option for producing value sets for EQ-5D, supplemented with bolt-on items. Future studies should further test this method using other bolt-on items and relevant study populations.

Testing 2 Alternative Time Trade-Off Methods for Valuation of Children's Health States.

OBJECTIVES: Composite time trade-off (cTTO) values for EQ-5D-Y-3L health states tend to be high, raising concerns about sensitivity particularly for mild or moderate health states. We conceptualized and pilot tested 2 alternative time trade-off (TTO) variants: the caregiver TTO (CGTTO) and lag-time TTO (LTTO). METHODS: We collected CGTTO and LTTO data in China for 10 EQ-5D-Y-3L health states and compared the resulting values, respondent feedback, and task completion times with those from an EQ-5D-Y-3L valuation study using cTTO. We also examined how age and parental status of respondents could affect TTO values. RESULTS: A total of 304 participants were included in this study. Overall, cTTO showed statistically better results in all feedback questions. On a 5-point Likert scale where lower score means greater agreement, the mean (SD) feedback scores for cTTO, LTTO, and CGTTO were 1.18 (0.58), 1.45 (0.91), and 1.65 (1.02) for "easy to understand"; 1.45 (0.91), 1.94 (1.08), and 1.86 (1.24) for "easy to differentiate"; and 3.61 (1.29), 2.97 (1.33), and 3.02 (1.50) for "difficult to decide," respectively. The mean (SD) TTO values of all 10 states were 0.463 (0.494), 0.387 (0.555), and 0.123 (0.710) for cTTO, LTTO, and CGTTO, respectively. The effects of age and parental status on TTO values differed by the 3 methods. CONCLUSIONS: LTTO and CGTTO produce values with good characteristics and merit further investigation. Researchers need to be aware of the differences in design and values when using the TTO method to value children's health states.

Testing "Pits" Time Trade-Off: Can Data Quality be Improved by Removing Death From Valuation of Health States?

OBJECTIVES: Composite time trade-off (cTTO) often exhibits issues such as a value clustering at -1, potentially due to suboptimal valuation task design. We developed a novel time trade-off which uses the "pits" state as an anchor state and enables a unified time trade-off procedure for all health states (referred to as "pTTO"). This study aimed to test the pTTO for valuation of EQ-5D-5L health states. METHODS: A total of 120 members of the general public were invited to value 3 pairs of dominant/dominated EQ-5D-5L states using both cTTO and pTTO and the "pits" state using cTTO. We compared the pTTO with cTTO in terms of feasibility (interviewer-rated task-completing difficulty), acceptability (participant-reported task experience), value distribution, logical consistency, and discriminatory ability (using the standardized response mean, an effect size measure, derived from 3 pairwise comparisons of states with dominant/dominated relationship). RESULTS: The pTTO demonstrated similar feasibility to cTTO but slightly lower acceptability. The pTTO values exhibited a smoother and more continuous distribution compared with cTTO values. Relative to the cTTO, the pTTO showed higher individual-level logical consistency rate for the pairs comprising severe states (stringent criterion: 53.04% vs 17.39%; less stringent criterion: 82.61% vs 78.26%). The standardized response mean value based on pTTO values were higher than those based on cTTO values for the pair comprising severe states (0.388 vs -0.140). CONCLUSIONS: The pTTO appeared to be feasible and acceptable to value EQ-5D-5L states. The pTTO values were less clustered, more logically consistent, and discriminative compared with the cTTO values for severe health states.

Censoring Time Trade-off Values at 0 Versus at -1: How Does the Assumption for Worse-Than-Dead Time Trade-off Values Affect the Modeling of EQ-5D-5L Valuation Data?

OBJECTIVES: A recent study found that negative utility values elicited using composite time trade-off (TTO) were barely associated with the severity of EQ-5D-5L health states, suggesting poor discriminative ability. Assuming negative values provide limited information, this study aimed to explore the usefulness of censoring negative TTO values at 0 in modeling EQ-5D-5L valuation data. METHODS: We analyzed EQ-5D-5L valuation data from China, The Netherlands, Canada, Singapore, and Thailand. For each data set, we estimated value sets using 2 Tobit models, one left-censored at -1 (current practice) and one left-censored at 0 (our proposed method), and compared the model performances. We hypothesized that censoring at 0 and censoring at -1 would produce similar values, though on slightly different scales. RESULTS: When censoring at 0, logical inconsistencies and statistical significance were improved but the value range was compressed. In the cross-attribute level effects model, the 3-level parameters were similar between the models censored at 0 and -1, but the rank order of some dimension parameters was altered. Health state values predicted by the 2 censoring models approximated a perfect agreement after rescaling. CONCLUSIONS: Censoring TTO values at 0 improved model estimation and fit but produced higher utility values than models censoring at -1. Investigators of future EQ-5D value set studies using the composite TTO method are advised to examine the validity of negative TTO values before choosing modeling strategies.

Cross-Attribute Level Effects Models for Modeling Modified 5-Level Version of EQ-5D Health State Values: Is Less Still More?

OBJECTIVES: Cross-attribute level effects (CALE) model has demonstrated better predictive accuracy for out-of-sample health states than the conventional additive main-effects model in cross-validation analysis of the 5-level version of EQ-5D (EQ-5D-5L) composite time trade-off (cTTO) datasets. In this study, we aimed to further test the performance of CALE model using a different design and modified EQ-5D-5L states. METHODS: A total of 29 EQ-5D-5L self-care bolt-off states, 30 EQ-5D-5L states, and 31 EQ-5D-5L vision bolt-on states were selected from the same orthogonal array. A total of 600 university students were interviewed face-to-face to value a subset of these health states using the cTTO method. For each type of health state, we fitted both the conventional main-effects model and the CALE model. Predictive accuracy was assessed in a series of cross-validation analysis using the leave-one-state-out method. RESULTS: Overall, the CALE model outperformed the conventional model for each of the 3 types of health states in predicting the cTTO values of out-of-sample health states. The prediction accuracy of using the CALE model improved with the number of dimensions in health states, for example, the MAE decreased about 24%, 67%, and 77% for the EQ-5D-5L self-care bolt-off, EQ-5D-5L, and EQ-5D-5L vision bolt-on states, respectively, when using CALE models. CONCLUSION: Our study supported the strengths of the CALE model for modelling the utility values of both original and modified EQ-5D-5L health states. Investigators with limited resources may consider using the CALE model to lower the costs for their valuation studies for EQ-5D-5L or similar health state descriptive systems.

Urban/rural differences in preferences for EQ-5D-5L health states: a study of a multi-ethnic region in China.

OBJECTIVES: This study aimed to compare health preferences for EQ-5D-5L health states between urban and rural populations in China. METHODS: This study used pooled secondary data from two EQ-5D-5L valuation studies. Participants were recruited from Guizhou province and Chongqing municipality, China using quota sampling. Each participant was interviewed face-to-face to value a set of 15 or 16 out of 30 EQ-5D-5L health states using time trade-off (TTO) methods including composite TTO and other two variants. Regression analysis was used to compare health state preferences between urban and rural participants. RESULTS: A total of 597 participants (urban: 55.44%; rural: 44.56%) completed the valuation interviews. Both univariate and multivariable linear regression analyses showed that rural participants tended to value health states lower than urban participants regardless of severity of health states. The unadjusted and adjusted overall mean differences between the two groups were - 0.041 (95% confidence interval [CI] - 0.077, - 0.004, p-value = 0.031) and - 0.040 (95% CI - 0.078, - 0.002, p-value = 0.038), respectively. Predictions for the 3125 health states based on rural participants' health preferences were lower than those based on urban participants' health preferences. CONCLUSION: There were small, yet statistically significant, differences in EQ-5D-5L health states preferences between urban and rural populations in China. Future study aiming at establishing a national value set should pay more attention to the sample representativeness.

Censoring in the time trade-off valuation of worse-than-dead EQ-5D-5L health states: can a time-based willingness-to-accept question be the solution?

PURPOSE: The left censoring of values at -1 by design of the composite time trade-off (cTTO) tasks leads to excessive amount of -1 values in some EQ-5D-5L valuation studies. This study aimed to investigate whether a time-based willingness-to-accept (tWTA) question can be used to elicit values lower than -1 and improve the estimation of EQ-5D-5L values. METHODS: At the end of each cTTO task in the Taiwanese EQ-5D-5L valuation study, if the value of the health state was indicated to be lower than -1, a tWTA question eliciting the indifference point between a hypothetical life (i.e. x number of years in full health followed by 10 years in the health state) and immediate death was used to estimate its uncensored value. We compared the statistical characteristics of the censored and uncensored data. RESULTS: Four hundred and twenty-nine of 1,000 respondents were offered the tWTA question in a total of 1,071 cTTO tasks. In 79.55% of those tasks, indifference was not reached. Spearman's correlation with level summary score was -0.41 and -0.40 for negative uncensored and censored data, respectively. The logical inconsistency rates of the uncensored and censored data were 0.88% vs. 0.29%, respectively. Modelling of the uncensored data resulted in coefficients with greater uncertainty and much lower predictions. CONCLUSIONS: The elicitation of values lower than -1 using a tWTA question that grants more time for trading seems not a promising solution to the value censoring of the cTTO tasks. Other strategies for valuation of very poor health states should be explored.

Reduced quality of life, more technical challenges, and less study motivation among paramedic students after one year of the COVID-19 pandemic - a survey study.

INTRODUCTION: Despite the lack of knowledge about the SARS-CoV2 virus, the lack of personal protection gear among frontline healthcare workers, and lack of vaccines in the beginning of the pandemic, paramedic students in Norway contributed to the National response against the COVID-19 pandemic by working in test-stations, ambulance services, ambulance decontamination stations etc. Despite fear of contracting the COVID-19 reported by healthcare workers worldwide, paramedic students in Norway reported higher-than-average quality of life after four months of the COVID-19 pandemic (first pandemic wave). In this study we aimed to investigate how students reported their quality of life, study motivation and job satisfaction after one year of living with the COVID-19 pandemic. METHOD: At two data collection point, all paramedic students enrolled at Oslo Metropolitan University were invited to participate in a digital, online, self-administered survey. The first data collection was in June 2020 (the first pandemic wave), while the second data collection was in March 2021 (the third pandemic wave). Results from both samples were analyzed independently with descriptive statistics. Differences between the groups were analyzed using an independent T-test and Mann-Whitney-U test to discover changes over time. Multiple linear regression analysis was used to estimate the difference attributable to timing (first vs. the third wave), seniority, and student gender. RESULTS: The samples consist of slightly more female students than male students. The mean age in both samples is 24.6 years. Despite the higher-than-average level of quality of life in the first pandemic wave, results show that there was a significant reduction in students' health-related quality of life (p < 0.001, B -0.059, SE 0.016), study motivation (p = 0.002, 95% CI:0.09,0.41), and job satisfaction (p = 0.005, 95% CI:1.62,9.00) after the third pandemic wave in Norway. Surprisingly, students experienced more technical challenges in the third wave, e.g., poor internet connection, sound pollution, and poor picture quality, despite more experience among students and teachers. CONCLUSION: Our results show that paramedic students had significant worsening experiences in the late pandemic wave compared to the first pandemic wave. Universities and governments should learn from the COVID-19 pandemic to develop better preparedness plans for future pandemics and knowledge about students' well-being should be considered in future preparedness plans for higher education and the government plans for the education of front-line healthcare workers during a pandemic to facilitate the continuation of necessary education.

Normal B-cell ranges in infants: A systematic review and meta-analysis.

BACKGROUND: During the first year of life, B-cell level is a valuable indicator of whether external factors, such as exposure to B-cell-depleting therapies, have an adverse impact on immune system development. However, there are no standard reference ranges of B-cell levels in healthy infants by age. OBJECTIVE: Our aim was to estimate the normal range of B-cell levels in infants, by age, during the first year of life by pooling data from published studies. METHODS: Studies reporting B-cell levels measured by using flow cytometry and CD19 markers in healthy infants were identified via a systematic literature review. Quality and feasibility assessments determined suitability for inclusion in meta-analyses by age group and/or continuous age. Means and normal ranges (2.5th-97.5th percentile) were estimated for absolute and percentage B-cell levels. Sensitivity analyses assessed the impact of various assumptions. RESULTS: Of the 37 relevant studies identified, 28 were included in at least 1 meta-analysis. The means and normal ranges of B-cell levels were found to be 707 cells/µL in cord blood (range 123-2324 cells/µL), 508 cells/µL in infants aged 0 to 1 month (range 132-1369 cells/µL), 1493 cells/µL in infants aged 1 to 6 months (range 416-3877 cells/µL), and 1474 cells/µL in infants older than 6 months (range 416-3805 cells/µL). The continuous age model showed that B-cell levels peaked at week 26. Trends were similar for the percentage B-cell estimates and in sensitivity analyses. CONCLUSION: These meta-analyses provide the first normal reference ranges for B-cell levels in infants, by week of age, during the first year of life.

Investigating 5-Level EQ-5D (EQ-5D-5L) Values Based on Preferences of Patients With Heart Disease.

OBJECTIVES: Several studies have shown that patients with heart disease value hypothetical health states differently from the general population. We aimed to investigate the health preferences of patients with heart disease and develop a value set for the 5-level EQ-5D (EQ-5D-5L) based on these patient preferences. METHODS: Patients with confirmed heart disease were recruited from 2 hospitals in Singapore. A total of 86 EQ-5D-5L health states (10 per patient) were valued using a composite time trade-off method according to the international valuation protocol for EQ-5D-5L; 20-parameter linear models and 8-parameter cross-attribute level effects models with and without an N45 term (indicating whether any health state dimension at level 4 or 5 existed) were estimated. Each model included patient-specific random intercepts. Model performance was evaluated for out-of-sample and in-sample predictive accuracy in terms of root mean square error. The discriminative ability of the utility values was assessed using heart disease-related functional classes. RESULTS: A total of 576 patients were included in the analysis. The preferred model, with the lowest out-of-sample root mean square error, was a 20-parameter linear model including N45. Predicted utility values ranged from -0.727 for the worst state to 1 for full health; the value for the second-best state was 0.981. Utility values demonstrated good discriminative ability in differentiating among patients of varied functional classes. CONCLUSIONS: An EQ-5D-5L value set representing the preferences of patients with heart disease was developed. The value set could be used for patient-centric economic evaluation and health-related quality of life assessment for patients with heart disease.

EQ-5D-5L measurement properties are superior to EQ-5D-3L across the continuum of health using US value sets.

OBJECTIVE: The objective of this study was to compare the measurement properties of the US EQ-5D-3L, EQ-5D-5L, and -5L to -3L crosswalk value sets (3L; 5L; 5L > 3L) across the spectrum of health. METHODS: The three scoring approaches were compared in terms of range of scale, percent of worse-than-dead health states, and mean single-level transitions. Discriminative ability was compared by leveraging two cross-sectional datasets. A novel method was used to visualize and compare the responsiveness of 3L and 5L scoring approaches across EQ VAS values. RESULTS: The US 5L value set had the broadest range of scale at 1.573 (vs. 1.109 for 3L and crosswalk). The crosswalk had the smallest mean single-level transition of 0.061 (vs. 0.078 for 5L and 0.111 for 3L). The 5L value set tended to be more discriminative/greater statistical efficiency than the crosswalk (F-statistic ratio: 1.111, 95% CI 0.989-1.240) and 3L (F-statistic ratio: 1.102 95% CI 0.861-1.383) across levels of general health. The 5L was the most responsive value set between EQ VAS values of 25 and 75. CONCLUSION: These results imply greater sensitivity of the 5L to health changes and potentially lower incremental cost-utility ratios compared to the 3L.

Time trade-off with someone to live for: impact of having significant others on time trade-off valuations of hypothetical health states.

BACKGROUND: The TTO task involves giving up life years, i.e. living a shorter life, to avoid an undesirable health state. Despite being a hypothetical task, some respondents take other life factors into account when completing the task. This study explored the effect of having children and/or a partner on TTO valuations of hypothetical EQ-5D-5L health states in a valuation study of the general population. METHODS: The study used TTO data collected in a Norwegian EQ-5D-5L valuation study in 2019-2020, by one-to-one pc-assisted interviews following the EQ-VT protocol. We used regression modelling to determine the effect of significant others (having children or a partner) on disutility per health state from the TTO valuations. RESULTS: 430 respondents were included [mean age 43.8 (SD 15.9) years, 58% female, 48% with children, 68% with a partner, 25% with neither children nor partner]. Having children and/or a partner was associated with lowered willingness to trade life years translating to higher elicited health state utilities (p < 0.01). CONCLUSION: Having significant others, or the lack of having significant others, was associated with respondents' valuation of hypothetical health states using TTO, more so than traditional sampling variables such as age and sex. Inadequate representativeness in terms of having significant others could bias health state preference values in valuation studies.

Norwegian population norms for the EQ-5D-5L: results from a general population survey.

PURPOSE: To provide the first Norwegian EQ-5D-5L and EQ VAS population norms for the adult general population. METHODS: Postal survey of a random sample of 12,790 Norwegians identified through the National Registry of the Norwegian Tax Administration. Norms, weighted for Norwegian general population characteristics, are shown for the five EQ-5D-5L dimensions, EQ-5D index, and EQ VAS scores for seven age categories, females, males, and education level. RESULTS: There were 3200 (25.9%) respondents to 12,263 correctly addressed questionnaires. The EQ-5D-5L dimensions, EQ VAS, and background questions were completed by 3120 (24.6%) respondents. The mean age (SD) was 50.9 (21.7) and range was 18-97 years. The youngest age group of 18-29 years and oldest of 80 years and over had the highest (n = 691) and lowest (n = 239) number of respondents, respectively. Compared to the general population, the respondents comprised a greater number of females, younger and older ages, and had a higher education level. 32% of respondents reported no health problems on the EQ-5D-5L. From the youngest to oldest age groups, there was a general decline in health as assessed by the EQ-5D-5L. The exception was for anxiety/depression, where the youngest age groups had the poorest health. Apart from self-care, women reported poorer health than men, as assessed by the EQ-5D-5L; EQ VAS scores were similar for men and women. Higher levels of health (EQ-5D index, EQ VAS scores) were found with increasing levels of education. CONCLUSION: The population norms will improve interpretation of EQ-5D-5L and EQ VAS scores in Norwegian applications including clinical practice, clinical and health services research, and national quality registers where EQ-5D-5L is the most widely used patient-reported instrument.

Estimating the EQ-5D-5L value set for the Philippines.

BACKGROUND: The Philippines has recommended the use of Quality-Adjusted Life Years (QALYs) in government health technology assessments (HTA). We aimed to develop a value set for the EQ-5D-5L based on health preferences of the healthy general adult population in the Philippines. METHODS: Healthy, literate adults were recruited from the Philippine general population with quota targets based on age, sex, administrative region, type of residence, education, income, and ethnolinguistic groups. Each participant's preference was elicited by completing Composite Time Trade-Off (C-TTO) and Discrete Choice Experiment (DCE) tasks. Tasks were computer-assisted using the EuroQol Valuation Technology 2.0. To estimate the value set, we explored 20- and 8-parameter models that either use c-TTO-only data or both c-TTO and DCE (also called hybrid models). Final model choice was guided by principles of monotonicity, out-of-sample likelihood, model fit, and parsimony. RESULTS: We recruited 1000 respondents with demographic characteristics that approximate the general population such as 49.6% Female, 82% Roman Catholic, 40% in urban areas, and 55% finished high school. None of the 20-parameter models demonstrated monotonicity (logical worsening of coefficients with increasing severity). From the 8-parameter models, the homoscedastic TTO-only model exhibited the best fit. From this model, mobility and pain/ discomfort had the highest effect on utilities. CONCLUSION: The selected model for representing the Philippine general population preferences for EQ-5D-5L health states was an 8-parameter homoscedastic TTO-only model. This value set is recommended for use in QALY calculations in support of HTA-informed coverage decisions in the Philippines.

Stroke unit demand in Norway - present and future estimates.

BACKGROUND: All stroke patients should receive timely admission to a stroke unit (SU). Consequently, most patients with suspected strokes - including stroke mimics (SM) are admitted. The aim of this study was to estimate the current total demand for SU bed capacity today and give estimates for future (2020-2040) demand. METHODS: Time trend estimates for stroke incidence and time constant estimates for length of stay (LOS) were estimated from the Norwegian Patient Registry (2010-2015). Incidence and LOS models for SMs were based on data from Haukeland University Hospital (2008-2017) and Akershus University Hospital (2020), respectively. The incidence and LOS models were combined with scenarios from Statistic Norway's population predictions to estimate SU demands for each health region. A telephone survey collected data on the number of currently available SU beds. RESULTS: In 2020, 361 SU beds are available, while demand was estimated to 302. The models predict a reduction in stroke incidence, which offsets projected demographic shifts. Still, the estimated demand for 2040 rose to 316, due to an increase in SMs. A variation of this reference scenario, where stroke incidence was frozen at the 2020-level, gave a 2040-demand of 480 beds. CONCLUSIONS: While the stroke incidence is likely to continue to fall, this appears to be balanced by an increase in SMs. An important uncertainty is how long the trend of decreasing stroke incidence can be expected to continue. Since the most important uncertainty factors point toward a potential increase, which may be as large as 50%, we would recommend that the health authorities plan for a potential increase in the demand for SU bed capacity.

Testing the "Nonstopping" Time Trade-Off: Is It Better Than the Composite Time Trade-Off?

OBJECTIVES: There are several issues of concern for the composite time trade-off (c-TTO) used to estimate EQ-5D-5L value sets. The "nonstopping" TTO (n-TTO) differs from the c-TTO mainly in 2 aspects: (1) n-TTO uses a standardized top-down or bottom-up routing; and (2) n-TTO continues when indifference is indicated by respondents. In this study, we aimed to test the feasibility of n-TTO and compared it with c-TTO. METHODS: The study was conducted in parallel in Norway and Singapore. In both countries, members of the general population were invited to complete 10 n-TTO or c-TTO tasks. Acceptability and feasibility of n-TTO were assessed using respondents' feedback, administration time, and valuation success rate. Characteristics of the TTO data derived from c-TTO and n-TTO tasks were examined at task, individual, as well as group levels. RESULTS: In both Norway and Singapore, the success rate of n-TTO tasks was high (> 95%) and the n-TTO tasks took less time to complete than the c-TTO tasks, and there were fewer or smaller "spikes" in the distributions of n-TTO data compared to c-TTO data. In Norway, the individual-level n-TTO and c-TTO data had similar distribution and logical consistency profiles. In Singapore, n-TTO was inferior to c-TTO in logical consistency; however, a similar degree of nonmonotonicity was observed in modeling of n-TTO and c-TTO data. CONCLUSIONS: The noniterative n-TTO appeared to be feasible and may generate data with better distribution in shorter time than c-TTO. Further research is needed to assess this new health-state valuation method.

Using the Choice Sequence in Time Trade-Off as Discrete Choices: Do the Two Stories Match?

OBJECTIVES: The EQ-5D-5L valuation protocol recommends combining time trade-off (TTO) and discrete choice experiments (DCEs). DCEs that include a duration attribute (DCETTO) allow modeling on the quality-adjusted life-year scale. Because the choice sequence in a TTO can be construed as a series of DCETTO, we used data from a single TTO study to investigate the extent to which DCE values match TTO values when based on identical preferences. METHODS: In a TTO design in which a fixed set of choices were administered without termination at preference indifference, 202 individuals each valued 10 EQ-5D health states. From identified indifference points, we estimated three sets of TTO values: (i) plotting means and (ii) applying censored regressions at -1 and 1. Using all strict preferences, we (iii) estimated DCETTO values with a logit model and a bootstrap procedure. RESULTS: Estimated DCETTO and TTO values agreed well at the severe end of the quality-adjusted life-year scale, but with decreasing severity, DCETTO values were higher than TTO-values, with the difference peaking at 0.37 for the mildest health state. Left-censoring TTO values at -1 worsen the agreement for the worst health states and did not affect health states. Right censoring at 1 improved the agreement for mild states. CONCLUSIONS: TTO and the DCETTO values estimated from the same preference data diverged, with increasing difference for milder health states. Although the values converged when applying censored regression at +1, we question the validity of this adjustment.

Valuation of Health States Considered to Be Worse Than Death-An Analysis of Composite Time Trade-Off Data From 5 EQ-5D-5L Valuation Studies.

OBJECTIVES: To evaluate the discriminative ability of negative values measured in 5-level EuroQol 5-dimensional questionnaire (EQ-5D-5L) value set studies. METHODS: This is a secondary analysis of EQ-5D-5L value set studies from Singapore, the Netherlands, China, Thailand, and Canada in which health state values were elicited from a general population sample using a composite time trade-off (TTO) method. Mean values were calculated for health states with same severity. The association between the mean values and severity was evaluated using Pearson correlation (r). A linear mixed model using severity as the fixed effect was fitted for values. The analyses were performed separately for positive values (from a conventional TTO for health states considered "better than death") and negative values (from a lead time TTO for health states considered "worse than death"). RESULTS: In Singapore (N = 1000; negative values 32.6%), the mean decreased with severity from 0.89 to 0.21 for positive values and increased with severity from -0.98 to -0.89 for negative values. The correlation between values and severity was much lower for negative values (r = -0.016) than for positive values (r = -0.614). The coefficient of severity in the linear mixed model for negative values was much smaller (coefficient = -0.009; pseudo-R2 < 0.001) compared with the model for positive values (coefficient = -0.041; pseudo-R2 = 0.337). Results using data sets from the other countries were similar. CONCLUSIONS: Negative values are not associated with severity of health states in EQ-5D-5L valuation studies, suggesting poor discriminative ability of the lead time TTO method in valuing health states considered worse than death.

Overview, Update, and Lessons Learned From the International EQ-5D-5L Valuation Work: Version 2 of the EQ-5D-5L Valuation Protocol.

A standardized 5-level EuroQol 5-dimensional questionnaire (EQ-5D-5L) valuation protocol was first used in national studies in the period 2012 to 2013. A set of problems encountered in this initial wave of valuation studies led to the subsequent refinement of the valuation protocol. To clarify lessons learned and how the protocol was updated when moving from version 1.0 to the current version 2.1 and 2.0, this article will (1) present the challenges faced in EQ-5D-5L valuation since 2012 and how these were resolved and (2) describe in depth a set of new challenges that have become central in currently ongoing research on how EQ-5D-5L health states should be valued and modeled.

A Norwegian 15D value algorithm: proposing a new procedure to estimate 15D value algorithms.

PURPOSE: So far there is no Norwegian value algorithm to inform healthcare decision making. The 15D health state values estimated with the original 15D valuation procedure tend to be higher than the values of other generic preference-based health-related quality of life (HRQoL) instruments. The main purpose of this study was to use a new 15D valuation procedure to estimate Norwegian 15D health state values and to explore their empirical performance. METHODS: The visual analogue scale was used to collect 15D valuation data in a representative sample of the Norwegian general population. The new procedure used fewer valuation tasks and anchored the 15D health state values in an empirically assessed range. The Norwegian 15D health state values were compared to the values of five HRQoL instruments which were provided by Norwegian residents belonging to seven disease groups and a healthy population. RESULTS: The Norwegian 15D health state values ranged from 1 to - 0.52. Compared to 15D health state values estimated with the original procedure, the Norwegian 15D health state values were lower and more in line with values of other HRQoL instruments. CONCLUSIONS: The new 15D valuation procedure is simpler, links the 15D health state values better to the requirements of the QALY model, and provides an empirically-based range. We recommend using the new valuation procedure in future 15D valuation studies, and the Norwegian health state values for use in 15D-based health economic analyses in Norway.