What PASSes for good? Experience-based Swedish and hypothetical British EuroQol 5-Dimensions preference sets yield markedly different point estimates and patient acceptable symptom state cut-off values in chronic arthritis patients on TNF blockade

Patient acceptable symptom state and treatment failure threshold values for work productivity and activity Impairment and EQ-5D-5L in osteoarthritis

OBJECTIVE

To estimate patient acceptable symptom state (PASS) and treatment failure (TF) threshold values for Work Productivity and Activity Impairment (WPAI) measure and EQ-5D-5L among people with hip or knee osteoarthritis (OA) 3 and 12 months following participation in a digital self-management intervention (Joint Academy®).

METHODS

Among the participants, we computed work and activity impairments scores (both 0-100, with a higher value reflecting higher impairment) and the Swedish hypothetical- (range: - 0.314 to 1) and experience-based (range: 0.243-0.976) EQ-5D-5L index scores (a higher score indicates better health status) at 3- (n = 14,607) and 12-month (n = 2707) follow-ups. Threshold values for PASS and TF were calculated using anchor-based adjusted predictive modeling. We also explored the baseline dependency of threshold values according to pain severity at baseline.

RESULTS

Around 42.0% and 48.3% of the participants rated their current state as acceptable, while 4.2% and 2.8% considered the treatment had failed at 3 and 12 months, respectively. The 3-month PASS/TF thresholds were 16/29 (work impairment), 26/50 (activity impairment), 0.92/0.77 (hypothetical EQ-5D-5L), and 0.87/0.77 (the experience-based EQ-5D-5L). The thresholds at 12 months were generally comparable to those estimated at 3 months. There were baseline dependencies in PASS/TF thresholds with participants with more severe baseline pain considering poorer (more severe) level of WPAI/EQ-5D-5L as satisfactory.

CONCLUSION

PASS and TF threshold values for WPAI and EQ-5D-5L might be useful for meaningful interpretation of these measures among people with OA. The observed baseline dependency of estimated thresholds limits their generalizability and values should be applied with great caution in other settings/populations.

Sensitivity analysis of EQ-5D-3L index scores in terms of discriminative and known-groups validity in SLE: introducing Adequate Health State

OBJECTIVES

To investigate the ability of different EuroQol 5-Dimensions 3-Levels (EQ-5D-3L) index scores to discriminate between verum drug and placebo (discriminant validity) as well as between responders and non-responders (known-groups validity) in the SLE patient population of two phase III clinical trials of belimumab.

METHODS

Data from the BLISS-52 (NCT00424476) and BLISS-76 (NCT00410384) trials (N = 1684), which both showed superiority of belimumab to placebo, were utilized. Responders were defined as SLE Responder Index 4 (SRI-4) achievers at week 52. The Pearson's χ2 and Mann-Whitney U tests were used for comparisons, and logistic regression analysis was used for adjustments for confounders and assessment of independence.

RESULTS

While full health state (FHS; EQ-5D index score 1) showed the best ability to discriminate between belimumab and placebo [adjusted odds ratio (OR) 1.47; 95% CI 1.11, 1.96; P = 0.008] and between SRI-4 responders and non-responders (adjusted OR 3.47; 95% CI 1.29, 10.98; P = 0.020), the discriminative ability of EQ-5D index scores 0.800 or more reached statistical significance for both discriminant validity (adjusted OR 1.29; 95% CI 1.02, 1.63; P = 0.036) and known-groups validity (adjusted OR 3.08; 95% CI 1.16, 9.69; P = 0.034).

CONCLUSION

Overall, higher EQ-5D index scores were associated with increasing ability to discriminate between belimumab and placebo, and between responders and non-responders. EQ-5D index scores less stringent than FHS may be clinically relevant health-related quality of life goals of treatment in patients with SLE, introducing the concept of EQ-5D adequate health state when FHS is not achievable.

Patient acceptable symptom state (PASS): thresholds for the EQ-5D-5L and Oxford hip and knee scores for patients with total hip and knee replacement

PURPOSE

To define patient acceptable symptom state (PASS) cut-off values for the EQ-5D-5L and Oxford hip (OHS) and knee (OKS) scores 6 and 12 months after total hip (THR) or knee (TKR) replacement. To compare PASS cut-off values for the EQ-5D-5L scored using: (1) the Canadian value set, (2) the crosswalk value set, and (3) the equal weighted Level Sum Score (LSS).

METHODS

We mailed questionnaires to consecutive patients following surgeon referral for primary THR or TKR and at 6 and 12 months post-surgery. Patient reported outcome measures (PROMs) were the EQ-5D-5L, the OHS, and OKS. We assessed PASS cut-off values for PROMs using percentile and ROC methods, with the Youden Index.

RESULTS

Five hundred forty-two surgical patients (mean age, 64 years, 57% female, 49% THR) completed baseline and 12-month questionnaires. 89% of THR and 81% of TKR patients rated PASS as acceptable at 12 months. PASS cut-off values for THR for the EQ-5D-5L (Canadian) were 0.85 (percentile) and 0.84 (Youden) at 12 months. Cut-off values were similar for the LSS (0.85 and 0.85) and lower for the crosswalk value set (0.74 and 0.73), respectively. EQ-5D-5L cut-off values for TKR were Canadian, 0.77 (Percentile) and 0.78 (Youden), LSS, 0.75 and 0.80, and crosswalk, 0.67 and 0.74, respectively. Cut-off values 6 and 12 months post-surgery ranged from 38 to 39 for the OHS, and 28 to 36 for the OKS (range 0 worst to 48 best).

CONCLUSION

PASS cut-off values for the EQ-5D-5L and Oxford scores varied, not only between methods and timing of assessment, but also by different EQ-5D-5L value sets, which vary between countries. Because of this variation, PASS cut-off values are not necessarily generalizable to other populations of TJR patients. We advise caution in interpreting PROMs when using EQ-5D-5L PASS cut-off values developed in different countries. A standardization of methods is needed before published cut-off values can be used with confidence in other populations.

Using the patient-acceptable symptom state to evaluate patients' perspectives of living with psoriasis: A cross-sectional study

BACKGROUND

Taking the perspectives of patients into consideration is of the utmost importance when defining treatment goals for psoriasis. The patient-acceptable symptom state (PASS) is a dichotomised question that captures patients' perceptions of their overall health state.

OBJECTIVES

To evaluate PASS and determine the factors associated with a satisfactory PASS for psoriatic patients.

METHODS

Three questions were asked: (Q1) Considering the ways that your skin symptoms affect your functioning, is your current skin psoriasis satisfactory? (Current PASS), (Q2) Considering the ways that your psoriasis is affecting you, if you were to remain in this state for the next few months, would this be satisfactory? (Future PASS) and (Q3) If you were to remain for the rest of your life as you were during the last 48 hours, would this be satisfactory? (Lifelong PASS). Disease severity, symptoms and health-related quality of life (HRQoL) were collected.

RESULTS

Of 140 patients, 74.3%, 70.0% and 85.7% expressed satisfaction with their current, future and lifelong skin psoriasis conditions respectively. A satisfactory PASS was significantly associated with older and married patients; lower disease severity; fewer skin symptoms; and a higher HRQoL. A multivariate analysis revealed that the independent factors associated with a satisfactory PASS were being older than 40 years, being married, practising meditation, not having extensive lesions at sensitive areas and having a high HRQoL.

CONCLUSIONS

PASS is a simple and easily administered questionnaire that reflects both disease severity and HRQoL. Understanding patients' needs and satisfaction levels will result in better care for psoriatic patients than otherwise.

Variations in Patients' Overall Assessment of Their Health Across and Within Disease Groups Using the EQ-5D Questionnaire: Protocol for a Longitudinal Study in the Swedish National Quality Registers

BACKGROUND

EQ-5D is one of the most commonly used questionnaires to measure health-related quality of life. It is included in many of the Swedish National Quality Registers (NQRs). EQ-5D health states are usually summarized using "values" obtained from members of the general public, a majority of whom are healthy. However, an alternative, which remains to be studied in detail, is the potential to use patients' self-reported overall health on the visual analog scale (VAS) as a means of capturing experience-based perspective.

OBJECTIVE

The aim of this study is to assess EQ VAS as a valuation method with an experience-based perspective through comparison of its performance across and within patient groups, and with that of the general population in Sweden.

METHODS

Data on nearly 700,000 patients from 12 NQRs covering a variety of diseases/conditions and nearly 50,000 individuals from the general population will be analyzed. The EQ-5D-3L data from the 12 registers and EQ-5D-5L data from 2 registers will be used in the analyses. Longitudinal studies of patient-reported outcomes among different patient groups will be conducted in the period from baseline to 1-year follow-up. Descriptive statistics and analyses comparing EQ-5D dimensions and observed self-assessed EQ VAS values across and within patient groups will be performed. Comparisons of the change in health state and observed EQ VAS values at 1-year follow-up will also be undertaken. Regression models will be used to assess whether EQ-5D dimensions predict observed EQ VAS values to investigate patient value sets in each patient group. These will be compared across the patient groups and with the existing Swedish experience-based VAS and time trade-off value sets obtained from the general population.

RESULTS

Data retrieval started in May 2019 and data of patients in the 12 NQRs and from the survey conducted among the general population have been retrieved. Data analysis is ongoing on the retrieved data.

CONCLUSIONS

This research project will provide information on the differences across and within patient groups in terms of self-reported health status through EQ VAS and comparison with the general population. The findings of the study will contribute to the literature by exploring the potential of self-assessed EQ VAS values to develop value sets using an experience-based perspective.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04359628; https://clinicaltrials.gov/ct2/show/NCT04359628.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/27669.

Similar responses to EQ-5D-3L by two elicitation methods: visual analogue scale and time trade-off

Background

Health-related quality of life (HRQoL) is often measured using EQ-5D-3L by the elicitation methods of visual analogue scale (VAS) and time trade-off (TTO). Although many countries have constructed both national VAS and TTO value sets, the fact that VAS and TTO value sets produces different values bewilders researchers and policymakers. The aim of this study is to explore certain conditions which could yield similar value sets using VAS and TTO.

Methods

A homogeneous sample of medical school students was selected to value 18 hypothetical health states using VAS and TTO methods. The 18 hypothetical health states were produced by orthogonal design (L18, 2*3^7). The range of rescaled values was transformed into − 1 ~ 0 ~ 1. The investigations via different methods were carried out by computer-assisted personal interviewing with a wash-time interval of 72 h. Value sets for VAS and TTO were constructed using general least square regression models. Independent variables were composed of 10 dummy variables from 5 dimensions and including or omitting both constant and N3 terms.

Results

Three hundred thirteen medical students participated. The mean age was 21.03 ± 0.44 years and 56.2% were female. The four regression models (for each method with and without constant and N3 terms) were all statistically significant (P < 0.05) with high goodness-of-fit (Adj. R² > 0.94 and MAE < 0.033). Differences between the coefficients of the 10 dummy variables corresponding to each model were all less than 0.059. Pearson correlation coefficients between observed means and predicted values exceeded 0.981. Fitted curves of VAS and TTO largely coincided.

Conclusions

VAS and TTO can generate similar responses under certain conditions, suggesting that the two valuation methods could be equivalent intrinsically. The VAS method appears a more valid approach for valuation in the general population due to its greater simplicity and feasibility.

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.

International comparison of experience-based health state values at the population level

BACKGROUND

Decision makers need to know whether health state values, an important component of summary measures of health, are valid for their target population. A key outcome is the individuals' valuation of their current health. This experience-based perspective is increasingly used to derive health state values. This study is the first to compare such experience-based valuations at the population level across countries.

METHODS

We examined the relationship between respondents' self-rated health as measured by the EQ-VAS, and the different dimensions and levels of the EQ-5D-3 L. The dataset included almost 32,000 survey respondents from 15 countries. We estimated generalized linear models with logit link function, including country-specific models and pooled-data models with country effects.

RESULTS

The results showed significant and meaningful differences in the valuation of health states and individual health dimensions between countries, even though similarities were present too. Between countries, coefficients correlated positively for the values of mobility, self-care and usual activities, but not for the values of pain and anxiety, thus underlining structural differences.

CONCLUSIONS

The findings indicate that, ideally, population-specific experience-based value sets are developed and used for the calculation of health outcomes. Otherwise, sensitivity analyses are needed. Furthermore, transferring the results of foreign studies into the national context should be performed with caution. We recommend future studies to investigate the causes of differences in experience-based health state values through a single international study possibly complemented with qualitative research on the determinants of valuation.