Quality-adjusted life years Totally Explained

Everything about Quality-adjusted Life Years totally explained

Quality-adjusted life years, or QALYs, is a way of measuring disease burden, including both the quality and the quantity of life lived, as a means of quantifying in benefit of a medical intervention. The QALY model requires utility independent, risk neutral, and constant proportional tradeoff behaviour. They are based on the number of years of life that would be added by the intervention. Each year in perfect health is assigned the value of 1.0 down to a value of 0 for death. If the extra years wouldn't be lived in full health, for example if the patient would lose a limb, or be blind or be confined to a wheelchair, then the extra life-years are given a value between 0 and 1 to account for this.
The meaning and usefulness of QALY is debated. Perfect health is hard, if not impossible, to define. Some argue that there are health states worse than death, and that therefore there should be negative values possible on the health spectrum (indeed, some health economists have incorporated negative values into calculations). Determining the level of health depends on measures that some argue place disproportionate importance on physical pain or disability over mental health. The effects of a patient's health on the quality of life of others - caregivers, family etc. also doesn't figure into these calculations.
The "weight" values between 0 and 1 are usually determined by methods such as:

Time-trade-off (TTO) - In this method, respondents are asked to choose between remaining in a state of ill health for a period of time, or being restored to perfect health but having a shorter life expectancy.
Standard gamble (SG) - In this method, respondents are asked to choose between remaining in a state of ill health for a period of time, or choosing a medical intervention which has a chance of either restoring them to perfect health, or killing them.
Visual analogue scale (VAS) - In this method, respondents are asked to rate a state of ill health on a scale from 0 to 100, with 0 representing death and 100 representing perfect health. This method has the advantage of being the easiest to ask, but is the most subjective.

Another way of determining the weight associated with a particular health state is to use standard descriptive systems such as the EuroQol EQ-5D questionnaire, which categorise health states according to the following dimensions: mobility, self-care, usual activities (for example work, study, homework or leisure activities), pain/discomfort and anxiety/depression.
However, the weight assigned to a particular condition can vary greatly, depending on the population being surveyed. Those who don't suffer from the affliction in question will, on average, overestimate the detrimental effect on quality of life, compared to those who are afflicted.
QALYs are used in cost-utility analyses to calculate the ratio of cost to QALYs saved for a particular health care intervention. This is then used to allocate healthcare resources, with an intervention with a lower cost to QALY saved ratio being preferred over an intervention with a higher ratio. This method is controversial because it means that some people won't receive treatment as it's calculated that cost of the intervention isn't warranted by the benefit to their quality of life. However, its supporters argue that since health care resources are inevitably limited, this method enables them to be allocated in the way that's most beneficial to society.

Further Information

Get more info on 'Quality-adjusted Life Years'.

External Link Exchanges

Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:

<a href="http://quality-adjusted_life_years.totallyexplained.com">Quality-adjusted life years Totally Explained</a>

Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned.