“Disability Adjusted Life Years”, definition from WHO: “One DALY represents the loss of the equivalent of one year of full health” (for a disease or health condition).
I always think this should be called “Disability adjustments to life years” … it’s not a ‘count of total adjusted years’. Anyways, moving on to HLI:
WELLBY’s, HLI
Instead of DALYs, we think in terms of WELLBYs (wellbeing-adjusted life years). …
Saying ‘wellbeing-adjusted life years’ suggests this involves a metric where people would trade off (‘adjusted’) an additional year of life spent at one level of happiness versus something else.
Or, to bring the ‘DALY’ concept in, something like …the adjustment to lifetime average well-being needed to be willing to give up an additional year of life in my current well-being state. Something like a ‘hypothetical revealed preference tradeoff’.
So what is one WELLBY? It’s a one-point increase on a 0-10 life satisfaction scale for one year.
But this is an explicit measure defined based on a survey response. So how would this be consistent with the ‘adjustment’ above
Q/DALYs are intended to measure health and the weights are found by asking individuals to make various trade-offs. There are some subtleties between them, but nothing important for this discussion.
WELLBYs are intended to measure overall subjective wellbeing, and do so in a way that allows quality and quantity of life to be traded off. Subjective wellbeing is measures via self-reports, primarily of happiness and life satisfaction (see World Happiness Report; UK Treasury). I should emphasise that HLI did not invent either the idea of measuring feelings, or of the WELLBY itself—we’re transferring and developing ideas from social science. How much difference various properties make to subjective wellbeing, e.g. income, relationship, employment status, etc. are inferred from the data, rather than asking people for their hypothetical preferences. Kahneman et al. draw an important distinction between decision utility (what people choose, aka preferences) and experienced utility (how people feel, aka happiness). The motivation for the focus on subjective wellbeing is often that there is often a difference between them (due to e.g. mispredictions of the future) and, if there is, we should focus on the latter.
Hence, when you say
Saying ‘wellbeing-adjusted life years’ suggests this involves a metric where people would trade off (‘adjusted’) an additional year of life spent at one level of happiness versus something else.
I’m puzzled. The WELLBY is ‘adjusted’ just like the QALY and the DALY: you’re combining a measure of quality of life with a measure of time, not just measuring time. On the QALYs, a year at 0.5 health utility are worth half as much as at 1 health utility, because of the adjustment for quality.
So what is one WELLBY? It’s a one-point increase on a 0-10 life satisfaction scale for one year.
By this I assume you mean 1 WELLBY a 1-point increase in the self-reported measure itself (maintained over the course of the year). Is that it?
If so, how can I compare maks the similar ‘adjustments’ like for QALY.
On the QALYs, a year at 0.5 health utility are worth half as much as at 1 health utility, because of the adjustment for quality.
How would something similar work for a WELLBY? If it’s just the numeric self reported well-being, it shouldn’t imply anything like ‘a year at WELLBY= 8 is worth twice as much as a year at WELLBY-4’, should it? I assume there is another way this is done.
I’m finding the terminology difficult.
DALY s
“Disability Adjusted Life Years”, definition from WHO: “One DALY represents the loss of the equivalent of one year of full health” (for a disease or health condition).
I always think this should be called “Disability adjustments to life years” … it’s not a ‘count of total adjusted years’. Anyways, moving on to HLI:
WELLBY’s, HLI
Saying ‘wellbeing-adjusted life years’ suggests this involves a metric where people would trade off (‘adjusted’) an additional year of life spent at one level of happiness versus something else.
Or, to bring the ‘DALY’ concept in, something like …the adjustment to lifetime average well-being needed to be willing to give up an additional year of life in my current well-being state. Something like a ‘hypothetical revealed preference tradeoff’.
But this is an explicit measure defined based on a survey response. So how would this be consistent with the ‘adjustment’ above
Q/DALYs are intended to measure health and the weights are found by asking individuals to make various trade-offs. There are some subtleties between them, but nothing important for this discussion.
WELLBYs are intended to measure overall subjective wellbeing, and do so in a way that allows quality and quantity of life to be traded off. Subjective wellbeing is measures via self-reports, primarily of happiness and life satisfaction (see World Happiness Report; UK Treasury). I should emphasise that HLI did not invent either the idea of measuring feelings, or of the WELLBY itself—we’re transferring and developing ideas from social science. How much difference various properties make to subjective wellbeing, e.g. income, relationship, employment status, etc. are inferred from the data, rather than asking people for their hypothetical preferences. Kahneman et al. draw an important distinction between decision utility (what people choose, aka preferences) and experienced utility (how people feel, aka happiness). The motivation for the focus on subjective wellbeing is often that there is often a difference between them (due to e.g. mispredictions of the future) and, if there is, we should focus on the latter.
Hence, when you say
I’m puzzled. The WELLBY is ‘adjusted’ just like the QALY and the DALY: you’re combining a measure of quality of life with a measure of time, not just measuring time. On the QALYs, a year at 0.5 health utility are worth half as much as at 1 health utility, because of the adjustment for quality.
Thanks. When you say
By this I assume you mean 1 WELLBY a 1-point increase in the self-reported measure itself (maintained over the course of the year). Is that it?
If so, how can I compare maks the similar ‘adjustments’ like for QALY.
How would something similar work for a WELLBY? If it’s just the numeric self reported well-being, it shouldn’t imply anything like ‘a year at WELLBY= 8 is worth twice as much as a year at WELLBY-4’, should it? I assume there is another way this is done.