Restricted Mean Survival Time
Restricted mean survival time (RMST) is the mean event-free time up to a set horizon, the area under the survival curve, used to compare treatments in HTA.
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.
Return on Assets
Return on assets (ROA) is net income divided by average total assets, a ratio used to judge how well hospitals and health systems use their assets.
Return on Equity
Return on equity (ROE) is net income divided by owners' equity, used in health economics to judge the profitability of hospitals, insurers and drug firms.
Return on Investment
Return on investment (ROI) is a health programme's monetary benefits minus its costs, divided by its costs, reported as a ratio or a percentage.
Reynolds-Smolensky
The Reynolds-Smolensky index measures how far a tax or health care payment changes income inequality, comparing inequality before and after the payment.
Right Censoring
Right censoring occurs when follow-up ends before a patient's event, such as death, so the survival time is known only to exceed the last time observed.
Risk Aversion
Risk aversion is a preference for a sure outcome over a gamble with the same expected value, seen in health insurance demand and cautious treatment choice.
Risk Evaluation
A formal assessment of a drug's potential safety risks, sometimes resulting in a required mitigation strategy such as restricted distribution or mandatory counselling.
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.
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.
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.