Survival Function
A function giving the probability that a person survives without the event of interest beyond a specified point in time.
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.
Survival Regression
A modelling approach estimating the relationship between predictor variables and a time-to-event outcome, including the Cox model and parametric survival models.
Synthetic Control
A quasi-experimental method constructing a weighted combination of untreated units to serve as a comparison group resembling a treated unit before intervention.
System Dynamics Model
A modelling approach representing a complex system using stocks, flows, and feedback loops to capture how it evolves through internal dynamics.
T-Distribution
A continuous probability distribution similar to the normal but with heavier tails, used when estimating a mean from a small sample with unknown variance.
Tarone-Ware Test
A test comparing survival distributions using a weighting scheme between the log-rank and Peto tests, a compromise depending on when treatment differences emerge.
Taylor Series Expansion
A mathematical technique approximating a complex function using a polynomial series based on its derivatives at a single point, underlying the delta method.
Taylor Series Method
The practical application of a Taylor series expansion to derive an approximate variance formula for a function of random variables.
Technical Efficiency
A condition in which the maximum possible output is produced from given inputs, without regard to whether those inputs serve their highest-value use.
Test Statistic
A single numerical value calculated from sample data during a hypothesis test, used to judge whether to reject the null hypothesis.
Theil Index Health
An information theory based inequality measure applied to a health outcome's distribution, decomposable into inequality within and between population subgroups.
Therapeutic Index
A drug's safety margin, calculated as the ratio between the dose that produces toxicity and the dose producing the desired effect.
Threshold Analysis
A sensitivity analysis technique identifying the value at which an input parameter would need to be set for a model's conclusion to change.
Threshold Approach
A decision-making method that classifies an intervention as cost-effective or not based on whether its ICER falls below a predetermined threshold.
Time Dependency
A situation where the probability of a health state transition depends on elapsed time, such as time since diagnosis, rather than staying constant.
Time Horizon
The span of time over which an economic evaluation captures relevant differences in costs and outcomes among the options being compared.
Time Preference
The general tendency to prefer a benefit sooner rather than later, or a cost later rather than sooner, underlying the case for discounting.
Time Value of Money
The principle that a given sum of money is worth more today than the same sum received in the future.
Time-Driven ABC
A simplified variant of activity-based costing using the cost per unit of time for resource capacity and the time an activity takes, rather than activity surveys.
Time-Driven Activity-Based Costing
A costing method estimating a service's cost by multiplying the capacity cost rate of resources involved by the time required to complete each activity.