health economics Health economics is a branch of economics concerned with issues related to efficiency, effectiveness, value and behavior in the production and consumption of health and healthcare. Health economics is important in determining how to improv ...

, time trade-off (TTO) is a technique used to measure the

quality of life Quality of life (QOL) is defined by the World Health Organization as "an individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards ...

that a person or group is experiencing. An individual will be presented with a set of directions such as:

Imagine that you are told that you have 10 years left to live. In connection with this you are also told that you can choose to live these 10 years in your current health state or that you can choose to give up some life years to live for a shorter period in full health. Indicate with a cross on the line the number of years in full health that you think is of equal value to 10 years in your current health state.

The answer given by the individual shows how many years in the current health state they would be willing to 'trade off', in order to regain full health. This answer can be used to calculate the individual's quality of life in that health state. For example, an individual with severe

asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, cou ...

could be offered 10 years in their current condition, or a shorter length of time in full health. If this individual is willing to trade off two of the ten offered years in order to regain full health, this suggests that eight years in full health has the same value as ten years with severe asthma. In this case, the individual would have valued living with severe asthma at 0.8, relative to full health (defined as 1.0). TTO scores can be influenced by socio-demographic characteristics and attitudinal variables of respondents, such as age, gender, marital status, having children, health status, education level, socio-economic status, ethnicity, and religious beliefs. Also, they can be influenced by the effects of ill health on consumptive activities and non health-related utility. Time trade-off results are often used to calculate

quality-adjusted life year The quality-adjusted life year (QALY) is a generic measure of disease burden, including both the quality and the quantity of life lived. It is used in economic evaluation to assess the value of medical interventions. One QALY equates to one year i ...

s (QALYs), allowing healthcare decision makers to combine

mortality Mortality is the state of being mortal, or susceptible to death; the opposite of immortality. Mortality may also refer to: * Fish mortality, a parameter used in fisheries population dynamics to account for the loss of fish in a fish stock throug ...

and

morbidity A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...

into a single interval scale. Other tools that are used to determine quality of life are the

visual analogue scale The visual analogue scale (VAS) is a psychometric response scale that can be used in questionnaires. It is a measurement instrument for subjective characteristics or attitudes that cannot be directly measured. When responding to a VAS item, respond ...

(VAS), the standard gamble method, the

EQ-5D EQ-5D is a standardised measure of health-related quality of life developed by thEuroQol Groupto provide a simple, generic questionnaire for use in clinical and economic appraisal and population health surveys. EQ-5D assesses health status in terms ...

, the Health Utilities Index (HUI), etc.

References

{{Reflist Health economics Quality of life