A comparison of the responsiveness of EQ-5D-5L and the QOLIE-31P and mapping of QOLIE-31P to EQ-5D-5L in epilepsy

Abstract

ObjectiveTo investigate the responsiveness of and correlation between the EQ-5D-5L and the QOLIE-31P in patients with epilepsy, and develop a mapping function to predict EQ-5D-5L values based on the QOLIE-31P for use in economic evaluations.MethodsThe dataset was derived from two clinical trials, the ZMILE study in the Netherlands and the SMILE study in the UK. In both studies, patients’ quality of life using the EQ-5D-5L and QOLIE-31P was measured at baseline and 12 months follow-up. Spearman’s correlations, effect sizes (EF) and standardized response means (SRM) were calculated for both the EQ-5D-5L and QOLIE-31P domains and sub scores. Mapping functions were derived using ordinary least square (OLS) and censored least absolute deviations models.ResultsA total of 509 patients were included in this study. Low to moderately strong significant correlations were found between both instruments. The EQ-5D-5L showed high ceiling effects and small EFs and SRMs, whereas the QOLIE-31P did not show ceiling effects and also showed small to moderate EFs and SRMs. Results of the different mapping functions indicate that the highest adjusted R 2 we were able to regress was 0.265 using an OLS model with squared terms, leading to a mean absolute error of 0.103.ConclusionsResults presented in this study emphasize the shortcomings of the EQ-5D-5L in epilepsy and the importance of the development of condition-specific preference-based instruments which can be used within the QALY framework. In addition, the usefulness of the constructed mapping function in economic evaluations is questionable.Electronic supplementary materialThe online version of this article (doi:10.1007/s10198-017-0928-0) contains supplementary material, which is available to authorized users.

Comparison of clinical efficacy of oxcarbazepine and lamotrigine combined with escitalopram, and impact on prognostic quality of life in treating patients with epilepsy and depressive disorder

“…Adverse reactions of patients, which included nausea, lethargy, dizziness, headache, rash and loss of appetite from both groups throughout 6-month treatment were recorded and compared. The Quality of Life in Epilepsy-Patients-Weighted 31p scoring system was used to evaluate and compare the quality of life of patients 6 months after treatment (15). The following domains were assessed: Emotion, cognition, social relations, energy, health status and overall quality of life, with a total score of 100 points.…”

Comparisons of direct and indirect utilities in adult epilepsy populations: A systematic review

“…The indirect epilepsy-specific instrument QOLIE-89 provided the lowest quality of life scores. Wijnen et al 18 provided utilities for one direct, one indirect generic, and one indirect epilepsy-specific instrument, as obtained from 509 patients enrolled in the prospective SMILE and ZMILE cohort studies based in the UK and the Netherlands, respectively. The majority of patients were aged between 25 and 44 years, 53.0% were female, and they had at least two seizures in the 12 months prior to study enrollment.…”

“…Questionnaire responses are converted into utilities by predetermined tariffs attached to various possible health states that have been established previously in unrelated studies obtained from the general population, hence providing "indirect" utilities. 18 Given the central importance of QOLIE in epilepsy research, these values have also been included in this review. 9 This assesses five domains: mobility, pain/discomfort, usual activities, self-care, and anxiety/depression, and respondents rate each domain at one of three (original EQ-5D-3L) or five (updated EQ-5D-5L) levels, ranging from "no problems" through to "extreme problems."…”

“…Researchers recognize that disease-specific instruments such as QOLIE may provide more relevant information to clinicians than generic instruments, and mapping functions have been developed to predict values of generic utility instruments based on QOLIE scores for use in economic evaluations. 18 Given the central importance of QOLIE in epilepsy research, these values have also been included in this review. Table 1 summarizes differences between direct versus indirect methods for determining utilities.…”

Cost-utility, cost-effectiveness, and budget impact of Internet-based cognitive behavioral therapy for breast cancer survivors with treatment-induced menopausal symptoms

“…We believe this to be inherent to the aim of the current program, which is not primarily focused on improving overall HRQL, but rather on reducing overall levels of menopausal symptoms and perceived impact of HF/NS. When using a generic indicator of HRQL such as the SF-36, important gains in more specific domains are often missed due to the lack of responsiveness of the instrument [47], hence explaining the results from the deterministic sensitivity analysis. Therefore, cost-utility analyses should be supplemented by cost-effectiveness analyses in which the cost per condition-specific outcome are measured and taken into account in reimbursement decisions.…”