First-Order Index
A variance-based sensitivity measure, also called a Sobol index, quantifying the share of a model's output variance from a single parameter varying alone.
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.
Fixed Effects
A panel data modelling approach estimating a separate intercept for each individual or group, controlling for all its time-invariant characteristics.
Fleming-Harrington Estimator
A statistical technique for estimating the survival function from censored data, more flexible than the Kaplan-Meier estimator in weighting events over time.
Fleming-Harrington Test
A hypothesis test comparing survival distributions between groups, generalising the log-rank test by allowing different weights for events at different follow-up times.
Flexible Parametric Model
A class of survival models using flexible functions, such as restricted cubic splines, to represent the hazard or survival function beyond standard distributions.
Folding Back
The process of calculating a decision tree's expected values by working backward from final outcomes toward the initial decision node.
Force of Infection
The rate at which susceptible individuals become infected, determined jointly by disease prevalence and the rate and probability of transmission per contact.
Fractional Polynomial
A flexible modelling technique representing a non-linear relationship using a small number of power transformations of a continuous variable.
Frailty Model
A survival model incorporating an unobserved random effect, called frailty, to represent risk heterogeneity not captured by observed covariates.
Frequentist Analysis
A statistical inference approach based on the long-run frequency properties of estimators, calculated from observed data alone, unlike a Bayesian approach.
Full Economic Evaluation
An economic evaluation comparing two or more alternatives in terms of both costs and consequences, unlike a partial evaluation examining costs or outcomes alone.
Fully Incremental Analysis
A method comparing more than two mutually exclusive interventions by ranking them by effectiveness and calculating each option's ICER against the next best alternative.
Fundamental Cost Analysis
A cost analysis limited to the most basic categories of direct medical cost, without extension into indirect or intangible categories.
Future Value
The value a present sum of money will grow to after a specified period, given a particular rate of return.
Game Theory Health
The application of game theory, the study of strategic interaction, to problems such as price negotiations, provider competition, or vaccination decisions.
Gamma Distribution
A flexible probability distribution capable of representing increasing, decreasing, or constant hazard patterns, commonly used for time-to-event and cost data.
Gamma Model
A survival model assuming time-to-event data follow a gamma distribution, allowing hazard rates that increase, decrease, or stay constant over time.
Gaussian Process
A flexible statistical framework modelling an unknown function by treating any finite set of its values as jointly normally distributed.
Gaussian Process Regression
A non-parametric technique modelling an unknown function by treating any finite set of outputs as jointly normally distributed, giving predictions with uncertainty.
Gaussian Quadrature
A numerical integration technique approximating a definite integral using a weighted sum of function values at strategically chosen points.