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
- Beta DistributionBeta Probability Distribution, Beta Density
- A flexible probability distribution bounded between zero and one, commonly used to represent uncertainty in probability parameters.
- Bootstrap Standard ErrorBootstrapped SE, Resampled Standard Error
- An estimate of a parameter's statistical uncertainty, calculated as the standard deviation of its value across many resampled datasets via bootstrapping.
C
- Cost-Effectiveness AcceptabilityCE Acceptability, Acceptability Probability
- The probability that an intervention offers good value for money at a given willingness-to-pay threshold, accounting for uncertainty in the cost and effect estimates.
- Curative Model UncertaintyCure-Duration Uncertainty, Curative-Effect Uncertainty
- The uncertainty surrounding a model's assumption about how long a one-time treatment's curative effect will last, given trial follow-up far shorter than the modelled lifetime.
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.
- Decision AnalysisDecision-Analytic Approach, Decision Modelling Framework
- In health economics, a systematic quantitative approach to choosing among options under uncertainty by modelling their expected costs and consequences.
- Decision UncertaintyDecision Risk, Probability of Wrong Decision
- The probability that the currently preferred option in an evaluation is not actually the truly optimal choice, given uncertainty in the model's parameters.
- Deliberative ProcessDeliberation, Reasoned Deliberation
- A structured process of reasoned discussion of evidence and perspectives, used to reach well-justified decisions amid uncertainty or competing values.
- Dirichlet DistributionDirichlet Prior, Multivariate Proportion Distribution
- A multivariate distribution representing uncertainty in a set of proportions that must sum to one, such as transition probabilities from a state.
E
- Emerging Infection EconomicsEmerging Pathogen Economics, Novel Infection Economics
- The application of health economic evaluation to newly identified or newly significant infectious diseases, often marked by substantial scientific uncertainty.
- Evidence GapResearch Gap, Missing-Evidence Area
- An area of clinical or health economic uncertainty where insufficient or absent research evidence exists to confidently answer a relevant question.
- Evidence SynthesisEvidence Combination, Research Synthesis
- The structured integration and appraisal of findings from multiple studies to answer a defined question while accounting for comparability, bias and uncertainty.
- Expected LossExpected Opportunity Loss, Probability-Weighted Loss
- The probability-weighted average cost of making an incorrect decision under uncertainty, calculated across all possible states and their probabilities.
- Expected Net BenefitAverage Net Benefit, ENB
- Expected net benefit is the average net benefit of an alternative across the uncertainty represented in an economic evaluation, calculated at a stated cost-effectiveness threshold.
- Expected UtilityEU, Utility Under Uncertainty
- Expected utility is the probability-weighted average of the utilities assigned to an uncertain option's possible outcomes, used to rank choices under risk when preferences satisfy the required axioms.
- Expected Value AnalysisExpected-Value Decision Making, Mean-Outcome Analysis
- An approach to decision-making under uncertainty that evaluates options based on the probability-weighted average of their possible outcomes.
- Expected Value of Partial Perfect InformationEVPPI, Partial Perfect-Information Value
- The maximum value of completely resolving uncertainty in a specific subset of a model's parameters, while other parameters remain uncertain.
- Expected Value of Perfect InformationEVPI, Perfect-Information Value
- Expected value of perfect information is the expected increase in net benefit from eliminating all decision-relevant uncertainty before choosing among the available strategies.
- Expected Value of Sample InformationEVSI, Sample-Information Value
- Expected value of sample information is the expected increase in the value of a decision when a specified study’s possible data can update uncertainty before a strategy is chosen.
F
- First-Order UncertaintyStochastic Uncertainty, Individual-Level Variability
- Uncertainty arising from variation among individual patients within a modelled population, unlike parameter uncertainty concerning imperfect knowledge of a true average value.
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.
H
- Heterogeneity AnalysisSubgroup Variation Study, Effect Heterogeneity Study
- An examination of how a model's results vary across different patient subgroups, unlike parameter uncertainty concerning imprecision in a single average population value.
I
- ImprecisionEffect Estimate Uncertainty, Wide Confidence Interval
- A GRADE evidence quality domain assessing whether a study's confidence intervals are narrow enough to support a confident conclusion about the true effect.
- Inferential StatisticsStatistical Inference, Inferential Methods
- A branch of statistics drawing conclusions about a broader population from sample data, incorporating formal methods for quantifying uncertainty.
- Interval EstimateInterval Estimation, Range Estimate
- A range of values, such as a confidence interval, calculated to convey the uncertainty surrounding a point estimate of a parameter.
J
- Jackknife Standard ErrorJackknife SE, Jackknife Variance Estimate
- An estimate of a parameter's statistical uncertainty calculated using the jackknife technique of omitting one observation at a time and examining resulting variability.
K
- Kalman FilterState Estimator, Recursive State Filter
- A recursive estimator that predicts an evolving latent state and updates that estimate and its uncertainty when a new noisy measurement arrives.
M
- Markov Chain Monte CarloMCMC, Posterior Sampling
- Markov chain Monte Carlo is a class of simulation methods that constructs a Markov chain with a chosen target distribution as its stationary distribution and uses dependent draws from the chain to approximate expectations and uncertainty under that distribution.
- Methodological UncertaintyMethods Uncertainty, Analytic Uncertainty
- Uncertainty arising from the choice of analytical methods or structural assumptions, such as discount rate, rather than the numerical values used within a fixed method.
- Monte Carlo SimulationMCS, Second-Order Simulation
- Monte Carlo simulation uses repeated random sampling to show how uncertainty in model inputs produces uncertainty in model outputs.
- Multiple ImputationMI, Rubin's Rules
- Multiple imputation is a missing-data method that creates several plausible completed datasets, analyses each for the same target, and pools the estimates and their uncertainty to reflect uncertainty about unobserved values.
N
- Nested LoopTwo-Level Simulation, Nested Monte Carlo
- A simulation structure in which one inner simulation runs repeatedly within each iteration of an outer simulation, used to separate sources of uncertainty.
O
- Opportunity LossEOL, Loss from Wrong Decision
- The difference in value between the outcome of the optimal decision and the outcome of the decision actually made under uncertainty.
P
- Parameter DistributionInput Distribution, PSA Distribution
- A parameter distribution is a probability model for the plausible values of an uncertain model input, specified from evidence and assumptions so its uncertainty can be propagated through an analysis.
- Parameter ImportanceParameter Influence, Input Importance
- A measure of how much a given input parameter contributes to the overall uncertainty in a model's results, used to prioritise further scrutiny.
- Parameter UncertaintyInput Uncertainty, Sampling Uncertainty
- Parameter uncertainty is uncertainty about the true values of quantities used as model inputs because those values are estimated from incomplete or imperfect evidence.
- Precision AssessmentPrecision Appraisal, Imprecision Rating
- An evaluation of an effect estimate's statistical precision, typically judged by the width of its confidence interval, wider meaning greater uncertainty.
- 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 of Cost-EffectivenessProbability CE, Likelihood of Cost-Effectiveness
- The probability of cost-effectiveness is the model-based probability that an intervention meets a stated net-benefit criterion against specified alternatives at a given willingness-to-pay threshold under the assumed uncertainty distribution.
Q
- Quality UncertaintyLemons Problem, Hidden-Quality Problem
- A condition in which buyers cannot reliably judge a good's quality before purchase, risking markets dominated by lower-quality offerings.
R
- ResamplingSample Reuse, Repeated Subsampling
- A family of statistical methods that draw repeated samples from observed data to estimate uncertainty or validate models, including the bootstrap, jackknife and cross-validation.
- Risk Sharing SchemeRisk Sharing Agreement, RSS, Outcomes-Based Scheme
- An arrangement distributing the financial or clinical uncertainty of a new treatment's real-world performance between manufacturer and payer, often linked to outcomes.
- Robust OptimisationRobust Optimization, Worst-Case Optimisation
- An optimisation approach that selects a feasible decision to perform well under the worst parameter values in a specified uncertainty set, often requiring constraints to hold throughout that set.
- Robust Standard ErrorRobust SE, Heteroskedasticity-Consistent Standard Error
- An estimate of a regression coefficient's statistical uncertainty that remains valid even when standard modelling assumptions, such as constant error variance, are violated.
S
- Second-Order UncertaintyDistributional Parameter Uncertainty, Hyperparameter Uncertainty
- Uncertainty about the parameters of a probability distribution itself, such as its true mean and variance, distinct from the variability the distribution represents.
- Stochastic ProgrammingOptimisation under Uncertainty, Recourse Programming
- An optimisation framework incorporating parameter uncertainty directly into the process, seeking a solution that performs well across possible parameter values.
- Structural UncertaintyModel-Structure Uncertainty, Structural Model Uncertainty
- Uncertainty about the appropriate form, pathways, states or mechanisms of a model, including plausible alternative structures that can change its predictions or decisions.
U
- UncertaintyImperfect Knowledge, Incomplete Information
- A general term describing imperfect knowledge of the true values, structure, or methodological choices underlying a health economic model.
- Uncertainty AssessmentUncertainty Evaluation, Uncertainty Appraisal
- A systematic evaluation of how confident decision-makers should be in a model's results, given parameter, structural, and methodological uncertainty.
- Uncertainty QuantificationUQ, Numerical Uncertainty Analysis
- The formal process of measuring how much confidence should be placed in a model's results, given the sources of uncertainty affecting it.