Risk Premium
A risk premium is the willingness to pay, above a risk's expected cost, to replace the risk with certainty, as when a household buys health insurance.
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.
Concepts, entries and ontology terms
A concept page is a published entry on the wiki. Some concepts also have a full encyclopaedia article. The Health Economics Ontology (HEO) holds every concept, including dictionary terms without an article, so it is larger than the list of published pages. The knowledge graph shows how concepts relate to each other.
Risk Ratio
The risk ratio (RR), or relative risk, is the risk of an event in one group divided by the risk in another over the same period, used in trials and HTA.
Risk Score
A risk score is a model-based number summarising a person's expected healthcare spending or chance of a health outcome over a set period such as a year.
Robust 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 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.
ROC Curve
The ROC (receiver operating characteristic) curve plots a test's sensitivity against its false positive rate at each cut-off, guiding thresholds in HTA.
Root Mean Square Error
The square root of the mean squared difference between numerical predictions and their corresponding observed values, expressed in the outcome’s original units.
Route of Administration
The specific pathway by which a drug enters the body, such as oral, intravenous, subcutaneous, or inhaled, affecting absorption and onset of action.
Royston-Parmar Model
The Royston-Parmar model is a parametric survival model that fits splines in log time to the log cumulative hazard, used to extrapolate survival in HTA.
Runge-Kutta Method
A Runge-Kutta method is a one-step numerical scheme for approximating the solution of an ordinary differential equation by combining several derivative evaluations within each integration step.
Sample Size Calculation
Sample size calculation sets how many participants a trial must analyse to detect a target clinical or economic difference at set power and significance.
Sandwich Estimator
The sandwich estimator is a variance formula for regression estimates that stays valid when cost data are heteroskedastic or patients are clustered.
Scarcity
Scarcity is the condition in which health care resources, such as funding, staff and beds, cannot meet every competing need, so choices must be made.
Scenario Analysis
Scenario analysis re-runs a health economic model under alternative assumptions, such as another survival extrapolation, to see if the decision changes.
Schoenfeld Residual
A Schoenfeld residual is the observed minus expected covariate value at each event in a Cox model, used to test the proportional hazards assumption.
Scitovsky Paradox
The Scitovsky paradox is a welfare economics result in which a policy and its reversal both pass the Kaldor-Hicks test used in cost-benefit analysis.
Scope Efficiency
Scope efficiency is whether a hospital or health system saves cost by providing several services together instead of in separate, specialised units.
Screening
Screening is the process of identifying apparently healthy people at increased risk of a condition, then offering information, further tests or treatment.
Screening Economics
The economic assessment of a screening programme’s full pathway, comparing its costs, health benefits, harms, budget implications and opportunity costs with feasible alternatives.
Screening Theory
Screening theory explains how an insurer or payer that cannot observe risk or cost offers a menu of contracts so each type reveals itself by its choice.