Dictionary
The Dictionary provides concise definitions of health economics terms, arranged alphabetically for quick reference. Use it to understand unfamiliar terminology or confirm the meaning of a specific term.
B
- Base CaseBase-Case Scenario, Central Estimate
- The set of central, best-estimate inputs used to produce a model's primary reported results, against which sensitivity analysis is later tested.
- Best Case AnalysisBest-Case Analysis, Optimistic Analysis
- A sensitivity analysis setting every uncertain input simultaneously to the value most favourable to the intervention, producing the most optimistic result.
D
- Data VisualisationData Visualization, Information Graphics
- In health economics and analytics, the graphical presentation of data to reveal patterns, relationships and uncertainty, such as plotting probabilistic sensitivity analysis results or quality-control trends.
- Delta AdjustmentDelta Sensitivity Analysis, Delta Imputation
- A sensitivity analysis technique shifting the assumed outcome for patients with missing trial data by a specified amount to test conclusions' robustness.
- Deterministic Sensitivity AnalysisDSA
- Deterministic sensitivity analysis evaluates how a model's results and decisions change when selected inputs or assumptions are assigned specific alternative values while all other stated conditions are controlled.
E
- Elementary EffectEE Measure, Morris Sensitivity Measure
- A measure in the Morris method of global sensitivity analysis, the change in output from a small, discrete change in one input.
F
- Factor FixingParameter Fixing, Negligible-Factor Screening
- A global sensitivity analysis technique identifying which input parameters have negligible influence on a model's output, so they could be fixed at a constant.
- Factor MappingOutput-Region Mapping, Monte Carlo Filtering
- A global sensitivity analysis technique identifying which combinations of input values produce outputs within a specific range of interest, such as below a threshold.
- Factor PrioritisationVariance-Based Ranking, Parameter Importance Ranking
- A global sensitivity analysis technique ranking input parameters by how much of a model's output variance each is responsible for.
- First-Order IndexFirst-Order Sobol Index, Sobol First-Order Index, Main-Effect Sensitivity Index, First-Order Sensitivity Index, S1
- A first-order index in variance-based sensitivity analysis is the fraction of model-output variance explained by changes in the conditional mean when one uncertain input varies on its own under the specified input distribution.
G
- Global Sensitivity AnalysisGSA, Simultaneous Sensitivity Analysis
- Global sensitivity analysis, or GSA, evaluates how uncertainty in model inputs contributes to variation in model outputs when inputs vary across their full specified ranges or distributions.
I
- IterationMonte Carlo Draw, Simulation Pass
- A single completed pass through a simulation model's calculations, typically using one randomly sampled set of parameter values in probabilistic sensitivity analysis.
L
- Local Sensitivity AnalysisLocal SA, Derivative-Based Sensitivity Analysis
- A sensitivity analysis examining how output changes with small variations around a fixed base case for each parameter, unlike global sensitivity analysis.
M
- Multi-Way Sensitivity AnalysisMultiway SA, Simultaneous Parameter Variation, Multi-Way Sensitivity
- An analysis systematically varying two or more input parameters together across a defined range of combinations, examining their combined effect on results.
- Multi-Way Threshold AnalysisMultiway Threshold, Joint Threshold Analysis
- A sensitivity analysis identifying the combinations of two or more parameter values at which a model's conclusion, such as cost-effectiveness, would change.
O
- One-Way SensitivityUnivariate Sensitivity, Single-Parameter Sensitivity
- A deterministic sensitivity analysis that varies one model input across a specified range while keeping the remaining inputs at their base-case settings, then recalculates the model outcome and any decision threshold.
- One-Way Sensitivity AnalysisOWSA, Univariate Sensitivity Analysis
- One-way sensitivity analysis is a deterministic method that changes one model input at a time across a specified range while holding all other inputs at their base-case values.
P
- Probabilistic Sensitivity AnalysisPSA, Probabilistic Analysis
- Probabilistic sensitivity analysis (PSA) characterises parameter uncertainty by assigning probability distributions to uncertain model inputs and propagating joint samples through the model.
- Probability DistributionStatistical Distribution, Distribution Function
- In health economics, a mathematical function describing the probabilities of the possible values of an uncertain quantity, used to represent parameter and individual-level variation in economic models and probabilistic sensitivity analysis.
R
- Random Number GenerationRNG, Random Draw Generation
- Random number generation supplies the uncertain draws used in probabilistic sensitivity analysis, microsimulation, discrete-event simulation, bootstrap procedures, and other stochastic analyses.
S
- Scatter PlotScatter Diagram, Scattergram, Scatter Chart
- A graphical display showing individual data points along two axes, commonly used to plot probabilistic sensitivity analysis results on the cost-effectiveness plane.
- Screening AnalysisParameter Screening, Factor Screening
- A preliminary sensitivity analysis technique efficiently identifying which of many input parameters meaningfully influence a model's output, for more detailed follow-up analysis.
- Sensitivity AnalysisSA, Robustness Analysis, Sensitivity Analysis Methods
- Sensitivity analysis examines how conclusions change when uncertain inputs, assumptions or model structures are varied.
- Sensitivity Analysis for Missing DataMissing Data Sensitivity Analysis, Delta-Adjustment Analysis
- Techniques assessing how much a study's conclusions might change under different, less favourable assumptions about missing data values.
- Spider PlotRadar Plot, Spider Diagram
- A graphical sensitivity analysis tool showing how a model's output changes as each input parameter is varied across its plausible range.
- Stochastic AnalysisStochastic Sensitivity Analysis, Random-Input Analysis
- An analysis in which a model incorporates randomness explicitly, so repeated runs under the same inputs can produce different results, unlike a deterministic model.
- Structural Sensitivity AnalysisStructural SA, Model-Structure Sensitivity
- A sensitivity analysis testing how results change under alternative structural assumptions, such as a different survival extrapolation function, rather than parameter values.
T
- Threshold AnalysisThreshold Analysis Method, Switching-Value 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.
- Tornado DiagramTornado Plot, Tornado Chart
- A horizontal bar chart displaying one-way sensitivity analysis results, bars ranked from largest to smallest range, resembling a tornado shape.
- Two-Way Sensitivity AnalysisTwo-Way Sensitivity, Bivariate Sensitivity Analysis
- An analysis varying two parameters together across a grid of combinations, typically shown as a contour plot or heat map of results.
V
- Variance-Based SensitivityVariance-Based SA, Sobol Sensitivity Analysis
- Global sensitivity analysis techniques, including Sobol indices, decomposing total output variance into components attributable to each parameter and their interactions.
W
- Worst Case Analysis
- A sensitivity analysis setting every uncertain parameter simultaneously to its least favourable value, producing the most pessimistic possible result the model could generate.