Time Preference
Time preference is the preference for benefits sooner and costs later; in health economics it is one reason future costs and QALYs are discounted.
Encyclopaedia
Explore comprehensive, evidence-informed explanations of key health economics concepts, including their development, application and relationships to other concepts. Published entries are validated through human expert review.
Concepts, entries and ontology terms
A concept page is a published entry on the wiki. Some concepts also have a full encyclopaedia article. The Health Economics Ontology (HEO) holds every concept, including dictionary terms without an article, so it is larger than the list of published pages. The knowledge graph shows how concepts relate to each other.
Time Trade-Off
The time trade-off (TTO) values a health state for QALYs by asking how many years in full health a person rates equal to a longer life in that state.
Time Value of Money
The time value of money is the principle that money held now is worth more than the same sum later, the reason economic evaluations discount future costs.
Time Without Symptoms of Progression
Time without symptoms of progression (TWiST) is survival free of disease symptoms and counted treatment toxicity, the reference state in Q-TWiST.
Time-Driven Activity-Based Costing
Time-driven activity-based costing (TDABC) costs health care by multiplying each resource's cost per minute of capacity by the minutes a patient uses.
Time-Homogeneous Model
A time-homogeneous model is a Markov model whose transition probabilities are the same in every cycle, so health state risks never change with age or time.
Time-Inhomogeneous Model
A time-inhomogeneous model is a Markov model whose transition probabilities can change between cycles, so a risk such as death can rise as the cohort ages.
Time-Lag Bias
Time-lag bias is distortion of the evidence available at a given time because studies with favourable or significant results are published sooner.
Time-to-Event
Time-to-event data record the time until an event such as death or progression, with some times censored, and supply survival inputs to economic models.
Time-Varying Covariate
A time-varying covariate is a predictor in a survival model, such as drug use or a biomarker level, whose value is updated during follow-up.
Time-Varying Hazard
A time-varying hazard is an event rate among people still at risk that rises, falls or turns over follow-up, as in many health economic survival models.
Timed Up and Go Test
Timed Up and Go Test (TUG) is a performance outcome timing how long a person takes to rise, walk 3 metres, turn and sit, used for mobility and falls risk.
Tolerance Interval
A tolerance interval is a range that, with stated confidence, encloses at least a set share of individual values in a population, such as patient costs.
Top-Down Costing
A costing approach that starts with aggregate costs and allocates them to services, activities or patients using documented shares and output counts.
Tornado Diagram
A tornado diagram is a bar chart of one-way sensitivity results in a cost-effectiveness model, ranking inputs so the widest swing in the result is on top.
Total Effect Index
The total effect index is the share of a health economic model output's variance due to one uncertain input, counting its main effect and all interactions.
Toxicity Period (TOX)
Toxicity period (TOX) is the Q-TWiST state for time with the treatment toxicity an analysis counts, often grade 3 or worse, weighted by its own utility.
Tragedy of the Commons
The tragedy of the commons is the overuse of a shared resource, such as antibiotic effectiveness, when each user keeps the gain but the cost falls on all.
Transaction Cost
A transaction cost is the cost of finding, negotiating, monitoring and enforcing an exchange, such as a health service contract, beyond the price paid.
Transient State
A transient state is a health state in a Markov model that patients eventually leave for good, possibly after several stays, unlike an absorbing state.