A conceptual map of health-related quality of life dimensions: key lessons for a new instrument

Jan Abel Olsen,Roseanne Misajon

doi:10.1007/s11136-019-02341-3

Abstract

PurposeQuality-adjusted life years (QALYs) represent a critical metric in economic evaluations impacting key healthcare decisions in many countries. However, there is widespread disagreement as to which is the best of the health state utility (HSU) instruments that are designed to measure the Q in the QALY. Instruments differ in their descriptive systems as well as their valuation methodologies; that is, they simply measure different things. We propose a visual framework that can be utilized to make meaningful comparisons across HSU instruments.MethodsThe framework expands on existing HRQoL models, by incorporating four distinctive continua, and by putting HRQoL within the broader notion of subjective well-being (SWB). Using this conceptual map, we locate the five most widely used HSU-instruments (EQ-5D, SF-6D, HUI, 15D, AQoL).ResultsBy individually mapping dimensions onto this visual framework, we provide a clear picture of the significant conceptual and operational differences between instruments. Moreover, the conceptual map demonstrates the varying extent to which each instrument moves outside the traditional biomedical focus of physical health, to also incorporate indicators of mental health and social well-being.ConclusionOur visual comparison provides useful insights to assess the suitability of different instruments for particular purposes. Following on from this comparative analyses, we extract some important lessons for a new instrument that cover the domains of physical, mental and social aspects of health, i.e. it is in alignment with the seminal 1948 WHO definition of health.

Highlights

The last few decades have seen a proliferation in the development of health-related quality of life (HRQoL) instruments
As compared to previous comparisons of the domain contents in health state utility (HSU) instruments [1, 3], we extend the conceptual analysis beyond a simplistic physical versus psycho-social dichotomy, namely incorporating potential causal relationships and level of abstraction in the framework
The aim of this paper was first to develop a conceptual map to better understand in which ways the descriptive systems of five HSU-instruments differ

Summary

Introduction

The last few decades have seen a proliferation in the development of health-related quality of life (HRQoL) instruments. Given that the nature of HSU-instruments is to collect participants’ subjective descriptions by rating the severity of the various dimensions, rather than using objective indicators of health as measured by clinicians, this distinction is not represented on the conceptual map. As compared to the above three instruments, the SF-6D put more emphasis on psycho-social aspects of health One such psycho-social item has a generic heading; ‘mental health’, but the description of its various severity levels refers to being ‘depressed or very nervous’ at different frequencies (Fig. 5). In the context of the conceptual map, the suggested new descriptive system would contain: three symptom/impairment/cause indicators (pain, sleep, depression); three functioning/effect indicators (mobility, self-care, vitality), and; two ‘effect of effect’ indicators (personal relationships, social isolation)

Discussion

Findings

Compliance with ethical standards