Tag Archives: Quality of life

Measuring the Quality of Life: Holy Grail

The standard method to measure quality of life (QoL) is to convert a generic quality of life score to a utility value, thus:

Score on a generic quality of life questionnaire X Conversion factor (tariff) = Utility

The QoL score must be generic because it has to cover all ailments, from deafness to paraplegia to depression.

The conversion factor converts this score to a utility that provides a common 1-0 (best health to death) scale, but also allows for negative values (worse than death). The most commonly used QoL questionnaire is the EQ-5D, which has only five dimensions (mobility, ability to care for oneself, ability to perform usual activities, pain/discomfort, and anxiety/depression). There is reason to question whether this is sufficiently broad for health (narrowly defined) use. For instance, it might not fully capture the utility loss from blindness. If it does not fully capture health narrowly defined, then it may be assumed that it falls shorter still for health more broadly defined to include effects of social care, economic independence, and overall happiness. Scales such as the WALY (Wellbeing-Adjusted Life Years) scale try to capture these outcomes. However, it is cumbersome to have two separate scales; ideally we need one, covering the same dimensions, but without introducing distortions by double counting some of them, but not others. Work is ongoing to sort this all out by collating information on many dimensions and eliminating those that largely duplicate information that others capture more specifically.

Enter Amartya Sen, an economist who won the Economics Nobel Prize in 1998 (alright, technically the Svergies Riksbank Prize in Economic Sciences). He emphasised human capabilities and argued that happiness was not enough – it was more important to have the capacity to understand and appreciate what the world has to offer and to be involved politically, than to simply have a hedonic life. Professor Jo Coast, collaborator of CLAHRC WM, has produced a score called ICECAP-A (ICEpop CAPability measure for Adults) for the purpose of measuring capabilities.[1]

Capability-based measures and patient perceived quality of daily life are fundamentally different constructs and pin-point the fundamental philosophical distinctions that lie at the heart of the quality of care debate. Like Candide in Voltaire’s play, I would gladly sacrifice happiness for an intellectual appreciation of the world and what lies beyond.

— Richard Lilford, CLAHRC WM Director

Reference:

  1. Al-Janabi H, Flynn T, Coast J. Development of a self-report measure of capability wellbeing for adults: the ICECAP-A. Qual Life Res. 2012; 21(1): 167-76.
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Measuring Quality of Care

McGlynn and Adams [1] repeat a point frequently made by the CLAHRC WM Director – before using outcomes to judge the quality of care, first model plausible effects.[2] [3] Only a small fraction of an outcome may be amenable to improved care.

The rate of hospital deaths in the UK is about 3%. Allowing a generous 20% of those to be preventable sets an upper headroom for improvement of 0.6%. So don’t expect quality of care to show up in mortality statistics. Or, to take another example, about 1% of hospital patients suffer a preventable medication related adverse event.[4] So don’t expect improved medicine management to show up in quality of life scores among the hospital population.

— Richard Lilford, CLAHRC WM Director

References:

  1. McGlynn EA, Adams JL. What makes a good quality measure? JAMA. 2014; 312(15): 1517-8.
  2. Yao GL, Novielli N, Manaseki-Holland S,Chen YF, van der Klink M, Barach P, Chilton PJ, Lilford RJ. Evaluation of a predevelopment service delivery intervention: an application to improve clinical handovers. BMJ Qual Saf. 2012; 21(s1): i29-38.
  3. Girling AJ, Hofer TP, Wu J, Chilton PJ, Nicholl JP, Mohammed MA, Lilford RJ. Case-mix adjusted hospital mortality is a poor proxy for preventable mortality: a modelling study. BMJ Quality & Safety. 2012; 21: 1052-6.
  4. de Vries EN, Ramrattan MA, Smorenburg SM, Gouma DJ, Boermeester MA. The incidence and nature of in-hospital adverse events: a systematic review. Qual Saf Health Care. 2008; 17(3): 216-23.