Mapping the Haem-A-QoL to the EQ-5D-5L in patients with hemophilia.

OBJECTIVE: This study's objective was to develop an algorithm that mapping the Haem-A-QoL scores to EQ-5D-5L utility scores in patients with hemophilia in China. METHODS: A national sample of 862 patients with hemophilia completed both the EQ-5D-5L and Haem-A-QoL instruments. Eight regression models were selected to develop the mapping algorithm, they were: the ordinary least squares, general linear regression, Tobit regression, censored least absolute deviation, mixture beta regression, adjusted limited dependent variable mixture, the two-part, and robust MM-estimator model. Root mean squared error (RMSE), mean absolute error (MAE), and R-square (R2) calculated using the tenfold cross-validation and random sample validation methods were used to assess the predictive ability of the models. RESULTS: Based on RMSE, MAE, and R2, the mixture beta regression model with selected Haem-A-QoL subscale scores as the predicted variables showed the best performance. CONCLUSIONS: Our mapping algorithm bolsters the calculation of QALYs while conducting an economic evaluation of hemophilia-related interventions when only Haem-A-QoL data are available. The external validity of the algorithm should be further assessed in the other populations.

Investigating the Added Value of the EQ-5D-5L With Two Bolt-On Items in Patients With Hemophilia.

Objective: This study examined the impact of adding two condition-specific bolt-on items to the EQ-5D-5L and assessed their psychometric properties in patients with hemophilia. Methods: The data were obtained from a nationwide cross-sectional online survey of patients with hemophilia in China. Self-reported and proxy-reported data were analyzed separately. Ceiling effect, informativity, and discriminatory power of the EQ-5D-5L with two bolt-on items, dignity (DG), and bleeding (BL), were examined. Spearman's rank correlation (rho) was used to assess the associations of the EQ-5D-5L and two bolt-on items with the Hemophilia Quality of Life Questionnaire for Adults (Haem-A-QoL) and SF-12. Multiple regression analysis was performed to evaluate the explained variance of the EQ-5D-5L and bolt-on items in predicting EQ-VAS scores. Results: A total of 895 patients and 222 caregivers completed the questionnaire. The ceiling effect decreased from 1.9 to 0.6% and 5.9 to 0.9% when using the EQ-5D-5L and the EQ-5D-5L with two bolt-on items among participants with both self- and proxy-completed questionnaires. Both DG and BL were strongly correlated with Haem-A-QoL sum score [rho: DG = 0.64 (patient) vs. 0.66(proxy); BL = 0.49 (patient) vs. 0.31 (proxy)], SF-12 mental component [rho: DG = -0.36 (patient) vs. -0.41 (proxy); BL = -0.53 (patient) vs. -0.57(proxy)], and SF-12 physical component [rho: DG = -0.61 (patient) vs. -0.61 (proxy); BL = -0.35 (patient) vs. -0.39 (proxy)]. Known-group comparisons confirmed that the two bolt-on items had satisfactory discriminatory power. Multiple regression analysis indicated that adding two bolt-on items significantly increased the ability to predict EQ-VAS scores. The adjusted R 2 increased by 8.2 and 8.8% for reports completed by the patients or patients' proxy respondents, respectively. Conclusion: Adding the DG and BL bolt-on items can increase performance on the EQ-5D-5L in patients with hemophilia. A future valuation study will be carried out.

Evaluating the psychometric properties of the EQ-5D-5L and SF-6D among patients with haemophilia.

OBJECTIVE: The aim of this study was to evaluate the psychometric properties of the EQ-5D-5L and SF-6D, and to compare their performance among patients living with haemophilia in China. METHODS: A total of 875 Chinese patients completed the EQ-5D-5L, SF-6D, and Haem-A-QoL questionnaires. Construct validity of the EQ-5D-5L and SF-6D dimensions and indices was assessed by testing hypotheses relating these measures to Haem-A-QoL and clinical measures. The Spearman correlation coefficient was used to assess convergent validity, and one-way analysis of variance (F statistic) was used to assess the known-groups validity (discriminatory power). The agreement between EQ-5D-5L and SF-6D indices was assessed using the intraclass correlation coefficient (ICC) and the Bland-Altman plot. RESULTS: Both the EQ-5D-5L and SF-6D indices showed acceptable ceiling and floor effects. As hypothesised, both EQ-5D-5L and SF-6D were significantly correlated with Haem-A-QoL (both dimensions and overall score). EQ-5D-5L and SF-6D indices as well as EQ-VAS differentiated patients are known to differ in severity of haemophilia, bleeding status, disabling levels, and comorbidity. The F statistics in the known-groups comparisons suggested that the EQ-5D-5L was slightly more discriminative than the SF-6D. ICC (0.41) and Bland-Altman plot confirmed that the agreement between the EQ-5D-5L and SF-6D indices was poor. CONCLUSION: Both EQ-5D-5L and SF-6D showed satisfactory construct validity in the measurement of the HRQoL among patients with haemophilia. However, the two instruments may not be used interchangeably in this patient population due to their poor agreement and differing discriminatory power.