Stratified Sampling
A sampling technique dividing a population into distinct subgroups, called strata, and drawing a separate sample from each to ensure adequate representation.
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.
Strict Dominance
A situation where one intervention is unambiguously better than another because it is both less costly and more effective.
Structural Equation Model
A modelling framework combining factor analysis and regression to test hypothesised relationships among observed and unobserved, latent variables.
Structural Sensitivity Analysis
A sensitivity analysis testing how results change under alternative structural assumptions, such as a different survival extrapolation function, rather than parameter values.
Structural Uncertainty
Uncertainty from the choice of a model's fundamental structure or method, such as which health states to include, unlike parameter uncertainty within a given structure.
Studentized Residual
A standardised residual excluding an observation's own contribution to the model fit, a more robust diagnostic for identifying influential data points.
SUCRA
An abbreviation for the surface under the cumulative ranking curve, ranking treatments in a Bayesian network meta-analysis by probability of being most effective.
Suits Index
A measure of the progressivity of a tax or financing system, using a concentration curve plotting cumulative tax burden against cumulative income.
Sullivan Method
A technique for calculating health expectancy measures by combining age-specific mortality rates from a life table with age-specific prevalence rates of disability.
Supplier-Induced Demand
The phenomenon in which providers, using their informational advantage, influence the quantity or type of care demanded beyond what informed patients would choose.
Supply
The quantity of a good or service producers are willing and able to offer for sale at a given price over a specified period.
Supply Curve
A graph showing the relationship between price and the quantity producers are willing to supply, typically sloping upward as price rises.
Survival Analysis
A branch of statistics concerned with the time until an event of interest occurs, appropriately accounting for censored observations.
Survival Function
A function giving the probability that a person survives without the event of interest beyond a specified point in time.
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.
Symptom-Free Survival
A time-to-event measure defined as the time from treatment start until the onset or return of clinically significant symptoms.
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.
Take-Up Rate
The proportion of individuals eligible for an insurance product or subsidy who actually enrol, assessing a coverage programme's effectiveness.