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

Abstract

Purpose Quality-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. Methods The 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). Results By 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. Conclusion Our 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.

Dimensions Used in Instruments for QALY Calculation: A Systematic Review

“…Then, the scheme (study process and design, target population, etc.) followed in the development of an instrument often depends on the motivation behind its creation [ 14 ]. A distinction will therefore be made between specific and generic instruments.…”

Filling the psycho-social gap in the EQ-5D: the empirical support for four bolt-on dimensions

“…Second, we are able to compare the relative importance when weighting against either health or life satisfaction directly under the identical analysis framework. Last but not the least, this paper investigated the dimensions following a theoretical framework been proposed by O&M [ 5 ] and with an aim to propose a feasible solution to fill the psycho-social gap in the EQ-5D.…”

“…First, there are multiple ways to select bolt-on dimensions for EQ-5D. This study does not aim to empirically explore the potential bolt-on dimensions from scratch, but instead start from the theoretical framework outlined in the O&M paper [ 5 ]. Readers who are interested to know more about developing EQ-5D bolt-on dimensions, see Longworth et al [ 3 ].…”

“…The aim of the current paper is to inquire into the empirical support behind four bolt-on dimensions to the EQ-5D that were recently suggested by Olsen and Misajon (O&M) in this journal [ 5 ]. The chosen bolt-ons result from their analytical approach to identify common denominators in the existing GPBMs, including the new PROMIS instrument [ 6 ], and to consider relevant dimensions in the Personal Well-being Index [ 7 ].…”

“…Social Relationships capture social functioning with the inner circle of family and friends, and Community Connectedness measure the degree of social isolation. See O&M [ 5 ] for more theoretical support of these four bolt-on dimensions.…”