Does the correspondence between EQ-5D health state description and VAS score vary by medical condition?

Abstract

BackgroundThe EQ-5D health-related quality of life instrument comprises a health state classification (health problems by severity in five domains), followed by an evaluation using a visual analogue scale (VAS). Despite the EQ-5D’s use in health technology assessment and as a patient-reported outcome measure (PROM), the correspondence between the two parts of the instrument remains ill-understood. In this paper, we consider whether the association between health state classification and VAS score might vary by medical condition.MethodsEQ-5D data collected for studies of patients in four different clinical conditions or circumstances (stroke, low back pain, colposcopic investigation or cytological surveillance) were pooled to generate a sample of 3,851 patient records. VAS scores were regressed on reported problem severities, with the inclusion of intercept and slope dummy variables specific to condition.ResultsThe regression model achieved a goodness-of-fit of 0.54. Given its structure and the significance of the coefficients, the proportion of VAS scores which differed by condition for the same health state varied between 33.3 and 88.5 per cent of possible states.ConclusionsMany of the patients with different medical conditions or in receipt of different interventions recorded different VAS valuations, in spite of ostensibly being in the same EQ-5D-defined health states. By implication, it is probable that the same state-to-state change would by valued differently by patients experiencing different conditions.

Single‐item discrimination of quality‐of‐life–altering dysphagia among 714 long‐term oropharyngeal cancer survivors: Comparison of patient‐reported outcome measures of swallowing

“…Although there is an abundance of literature on the clinical relevance and meaning of EQ‐VAS scores, no consensus interpretation exists. However, studies consistently demonstrate an association between EQ‐VAS and the 5 EQ‐5D domains (mobility, self‐care, usual activities, pain/discomfort, and anxiety/depression) . Thus, although it is difficult to encapsulate an individual's perceived QOL in a single number, such wide differences in EQ‐VAS scores may suggest meaningful differences in overall health, independence in daily activities, and psychosocial functioning.…”

“…However, studies consistently demonstrate an association between EQ-VAS and the 5 EQ-5D domains (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression). 25,26 Thus, although it is difficult to encapsulate an individual's perceived QOL in a single number, such wide differences in EQ-VAS scores may suggest meaningful differences in overall health, independence in daily activities, and psychosocial functioning. Therefore, these survey results further highlight the large impact of dysphagia symptoms on overall QOL in OPC survivorship.…”

Real‐world impact of direct acting antiviral therapy on health‐related quality of life in HIV/Hepatitis C co‐infected individuals

“…The EQ‐5D has been noted to have problems with ceiling effects and therefore the use of the scale in individuals with early asymptomatic HIV infection is not recommended . The concern of a ceiling effect may also extend to people with asymptomatic HCV infections and maybe a reason why the improvement in health state post‐treatment based on the VAS did not translate to improvements of utility scores . Stratifying by fibrosis severity may address this concern.…”

Using the EuroQol EQ-5D in Swiss Cancer Patients, Which Value Set Should be Applied?

“…The EQFR, EQEU and EQUK utilities all show a similar correlation with VAS ratings. It is clear that higher correlations and degree of similarity between questionnaire-based EQ-5D utilities and VAS ratings cannot be interpreted as a per se indicator of better suitability of a value set, due to the conceptual differences between the two types of measures [15,21]. Nonetheless, Whyne et al [15] found that EQ VAS scores are predictable from EQ-5D health state classifications", indicating that some degree of correlation can be expected.…”