The nonparametric model was preferred for its simplicity while performing similarly to the other models. Being independent of the value set that is used, it can be applied to transform any EQ-5D-3L value set into EQ-5D-5L index values. Strengths of this approach include compatibility with three-level value sets. A limitation of any crosswalk is that the range of index values is restricted to the range of the EQ-5D-3L value sets.

PurposeThe aim of this study was to assess the measurement properties of the 5-level classification system of the EQ-5D (5L), in comparison with the 3-level EQ-5D (3L).MethodsParticipants (n = 3,919) from six countries, including eight patient groups with chronic conditions (cardiovascular disease, respiratory disease, depression, diabetes, liver disease, personality disorders, arthritis, and stroke) and a student cohort, completed the 3L and 5L and, for most participants, also dimension-specific rating scales. The 3L and 5L were compared in terms of feasibility (missing values), redistribution properties, ceiling, discriminatory power, convergent validity, and known-groups validity.ResultsMissing values were on average 0.8 % for 5L and 1.3 % for 3L. In total, 2.9 % of responses were inconsistent between 5L and 3L. Redistribution from 3L to 5L using EQ dimension-specific rating scales as reference was validated for all 35 3L–5L-level combinations. For 5L, 683 unique health states were observed versus 124 for 3L. The ceiling was reduced from 20.2 % (3L) to 16.0 % (5L). Absolute discriminatory power (Shannon index) improved considerably with 5L (mean 1.87 for 5L versus 1.24 for 3L), and relative discriminatory power (Shannon Evenness index) improved slightly (mean 0.81 for 5L versus 0.78 for 3L). Convergent validity with WHO-5 was demonstrated and improved slightly with 5L. Known-groups validity was confirmed for both 5L and 3L.ConclusionsThe EQ-5D-5L appears to be a valid extension of the 3-level system which improves upon the measurement properties, reducing the ceiling while improving discriminatory power and establishing convergent and known-groups validity.

No abstract

Cancer is one of the most frequent disease-specific applications of the EQ-5D. The objective of this review was to summarise evidence to support the validity and reliability of the EQ-5D in cancer, and to provide a catalogue of utility scores based on the use of the EQ-5D in clinical trials and in studies of patients with cancer. A structured literature search was conducted in EMBASE and MEDLINE to identify papers using key words related to cancer and the EQ-5D. Original research studies of patients with cancer that reported EQ-5D psychometric properties, responses and/or summary scores were included. Of 57 identified articles, 34 were selected for inclusion, where 12 studies reported evidence of validity or reliability and 31 reported EQ-5D responses or summary scores. The majority of investigations using the EQ-5D concerned patients with prostate cancer (n = 4), breast cancer (n = 4), cancers of the digestive system (n = 7) and Hodgkin and/or non-Hodgkin lymphoma (n = 3). Mean index-based scores ranged from 0.33 (SD 0.4) to 0.93 (SD 0.12) and visual analogue scale scores ranged from 43 (SD 13.3) to 84 (SD 12.0) across subtypes of cancer. A substantial and growing body of literature using the EQ-5D in cancer that supports the validity and reliability of EQ-5D in cancer has emerged. This review provides utility estimates for cancer patients across a wide range of cancer subtypes, treatment regimens and tumour stage(s) that may inform the modelling of outcomes in economic evaluations of cancer treatment.

The results of this investigation generally supported the validity of the EQ-5D. However, an important ceiling effect was observed for the EQ-5D in this sample. The combination of the EQ-5D and SF-12 provides relatively broad coverage of important health domains and scores for various purposes.