A qualitative examination of the content validity of the EQ-5D-5L in patients with type 2 diabetes.

Louis S Matza,Matthew Reaney,Amanda S Landrian,Katie D Stewart,Bradley H Curtis,Kristina S Boye

doi:10.1186/s12955-015-0373-7

Louis S Matza, Matthew Reaney + Show 4 more

Open Access

https://doi.org/10.1186/s12955-015-0373-7

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Abstract

BackgroundThe EQ-5D is frequently used to derive utilities for patients with type 2 diabetes (T2D). Despite widely available quantitative psychometric data on the EQ-5D, little is known about content validity in this population. Thus, the purpose of this qualitative study was to examine content validity of the EQ-5D in patients with T2D.MethodsPatients with T2D in the UK completed concept elicitation interviews, followed by administration of the EQ-5D-5L and cognitive interviewing focused on the instrument’s relevance, clarity, and comprehensiveness.ResultsA total of 25 participants completed interviews (52.0 % male; mean age = 53.5 years). Approximately half (52 %) reported that the EQ-5D-5L was relevant to their experience with T2D. When asked if each individual item was relevant to their experience with T2D, responses varied widely (24.0 % said the self-care item was relevant; 68.0 % said the anxiety/depression item was relevant). Participants frequently said items were not relevant to themselves, but could be relevant to patients with more severe diabetes. Most participants (92.0 %) reported that T2D and/or its treatment/monitoring requirements had an impact on their quality of life that was not captured by the EQ-5D-5L. Common missing concepts included food awareness/restriction (n = 13, 52.0 %); activities (n = 11, 44.0 %); emotional functioning other than depression/anxiety (n = 8, 32.0 %); and social/relationship functioning (n = 8, 32.0 %).ConclusionsThe results highlight strengths and potential limitations of the EQ-5D-5L, including missing content that could be important for some patients with T2D. Suggestions for addressing limitations are provided.

Highlights

The EQ-5D is frequently used to derive utilities for patients with type 2 diabetes (T2D)
The NICE guide adds that utilities derived via other methods may be acceptable for use in cost utility modeling when EQ-5D utilities are not “available” or “appropriate.” The recently updated version of the guide suggests that qualitative data may be useful for examining the appropriateness of the EQ-5D
Given that the instrument was intended to provide a brief tool for quantifying health status across all populations, it is encouraging that about half of this T2D sample said the instrument was relevant to their own experience

Summary

Introduction

The EQ-5D is frequently used to derive utilities for patients with type 2 diabetes (T2D). Generic preference-based instruments are frequently administered to estimate utility values for type 2 diabetes (T2D) health states for use in cost-utility modeling. The NICE guide adds that utilities derived via other methods may be acceptable for use in cost utility modeling when EQ-5D utilities are not “available” or “appropriate.” The recently updated version of the guide suggests that qualitative data may be useful for examining the appropriateness of the EQ-5D. To support a claim that the instrument is inappropriate, NICE suggests “qualitative empirical evidence on the lack of content validity for the EQ-5D should be provided, demonstrating that key dimensions of health are missing. This should be supported by evidence that shows that EQ-5D performs poorly on tests of construct

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