Scale agreement, ceiling and floor effects, construct validity, and relative efficiency of the PROPr and EQ-5D-3L in low back pain patients

BACKGROUND

The PROMIS Preference score (PROPr) is a new health state utility (HSU) score that aims to comprehensively incorporate the biopsychosocial model of health and apply favorable psychometric properties from the descriptive PROMIS system to HSU measurements. However, minimal evidence concerning comparisons to the EQ-5D-3L and the PROPr's capability to differentiate clinical severity are available. Therefore, the aim of this study was to compare the PROPr to the EQ-5D-3L in terms of scale agreement, ceiling/floor effects, distribution, construct validity, discriminatory power, and relative efficiency (RE) in terms of the Oswestry Disability Index (ODI) for patients with low back pain (LBP).

METHODS

We used intra-class correlation coefficients (ICC) and Bland-Altman plots to compare the PROPr and EQ-5D-3L with regared to scale agreement in a cross-sectional routine sample of LBP patients. For distribution, we used the Pearson's coefficient for skewness and for ceiling/floor effects, a 15%-top/bottom threshold. For convergent validity, we used Pearson's correlation coefficients. For known-groups validity, we applied a linear regression with interaction terms (predictors sex, age, and ODI level) and an analysis of variance (ANOVA). For discriminatory power, we calculated the effect size (ES) using Cohen's d and the ratio of the area under the receiver-operating characteristics curves (AUROC-ratio = AUROCPROPr/AUROCEQ-5D-3L). RE was measured using the ratio of F-values (RE = FPROPr/FEQ-5D-3L).

RESULTS

Of 218 LBP patients, 50.0% were female and the mean age was 61.8 years. The mean PROPr (0.20, 95%CI: 0.18; 0.22) and EQ-5D-3L scores (0.55, 95%CI: 0.51; 0.58) showed low agreement (d = 0.35, p < 0.001; ICC 0.27, 95%CI: -0.09; 0.59). The PROPr's distribution was positively skewed, whereas the EQ-5D-3L's was negative. Neither tool showed ceiling/floor effects, but all EQ-5D-3L dimensions did. Pearson correlation was r = 0.66 (95%CI: 0.58; 0.73). Differences were invariant to sex and age but not to ODI severity: ESEQ-5D-3L > ESPROPr and RE < 1 in higher ODI severity; ESEQ-5D-3L < ESPROPr and RE > 1 in lower ODI severity. AUROC-ratios did not show significant differences in terms of ODI severity.

CONCLUSIONS

All PROPr and EQ-5D-3L biopsychosocial dimensions of health showed impairment in LPB patients. The capability of EQ-5D-3L and PROPr to differentiate ODI levels depends on ODI severity. Joint application of both tools may provide additional information.

Health-Related Quality of Life (HRQoL) Using EQ-5D-5L: Value Set Derived for Indian Breast Cancer Cohort

OBJECTIVE

The purpose of this study was to report quality of life of newly diagnosed breast cancer patients from India in a large cohort using the EQ-5D-5L instrument.

METHODS

The study used longitudinal data of 500 breast cancer and 200 non-cancer subjects registered at our centre, during June 2019 and March 2022. The EQ-5D-5L and EQ-VAS instruments were used to measure and compare utility scores among cancer and non-cancer subjects. Descriptive statistics were analyzed and Tobit regression model were used to confirm the predictors of the utility score.

RESULTS

The cancer subjects had a mean EQ-ED-5L utility score of 0.8703 (SD=0.121), 0.8745 (SD=0.094) and 0.8902 (SD=0.107) at the time of baseline, completion and follow up surveys respectively.  EQ-5D-5L values had significantly worsened after diagnosis of cancer as compared to the non-cancer cohort (0.87 vs. 0.93, p value 0.000). EQ-5D-5L utility scores as per stage for the cancer cohort were 0.88, 0.86 and 0.83 respectively for stage I-II, III and IV. Similarly, the EQ-VAS scores for stage I-II, III and IV were 74.9, 72.6 and 73.2 respectively. Multivariate analysis confirmed strong association of age, religion and income with the utility-values.

CONCLUSION

This is the first longitudinal study reporting the utility scores derived from a large cohort of breast cancer patients demonstrating lower utility scores compared to non-cancer cohort. The utility scores also improve post treatment completion for cancer patients and decrease with higher stage at diagnosis. This information will be useful for future health economic research in India pertaining to breast cancer.

Communal Sharing and the Provision of Low-Volume High-Cost Health Services: Results of a Survey

INTRODUCTION

This paper suggests and tests a reason why the public might support the funding of services for rare diseases (SRDs) when the services are effective but not cost effective, i.e. when more health could be produced by allocating funds to other services. It is postulated that the fairness of funding a service is influenced by a comparison of the average patient benefit with the average cost to those who share the cost.

METHODS

Survey respondents were asked to allocate a budget between cost-effective services that had a small effect upon a large number of relatively well patients and SRDs that benefited a small number of severely ill patients but were not cost effective because of their high cost.

RESULTS

Part of the budget was always allocated to the SRDs. The budget share rose with the number sharing the cost.

DISCUSSION

Sharing per se appears to characterise preferences. This has been obscured in studies that focus upon cost per patient rather than cost per person sharing the cost.