Weibull Model
A survival model based on the Weibull distribution, representing an increasing or decreasing hazard over time, though restricted to a monotonic pattern.
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.
Weighted Least Squares Regression
Weighted least squares (WLS) is regression that weights each squared residual, ideally by the inverse of its error variance, as in meta-analysis for HTA.
Weighted Log-Rank
A survival-curve comparison test that weights each event-time observed-minus-expected count to emphasize a prespecified pattern of differences over follow-up.
Welfare Criterion
A welfare criterion is a decision rule that ranks policies or allocations as better or worse for society, such as the Pareto test or health maximisation.
Welfare Economics
Welfare economics is the normative branch of economics that judges whether changes in the allocation of resources and health make society better off.
Wilcoxon Test
The Wilcoxon test in survival analysis, or Gehan-Breslow test, compares survival curves by weighting each event time by the number still at risk.
Willingness to Accept
Willingness to accept (WTA) is the smallest sum a person would take as compensation to give up a good or bear a loss, such as a worse health state.
Willingness to Pay
Willingness to pay (WTP) is the most money a person would give up for a health gain or other benefit, used to value outcomes in cost-benefit analysis.
Willingness-to-Pay Estimation
Willingness-to-pay estimation is the econometric step that turns contingent valuation or discrete choice answers into money values for health benefits.
Willingness-to-Pay Threshold
A willingness-to-pay threshold is the cost per QALY below which a treatment counts as good value; strictly, the most society would pay for one extra QALY.
Within Subject Variation
Within-subject variation is the scatter of one patient's repeated measurements, such as utility scores or costs, around that patient's own usual level.
X-Efficiency
X-efficiency is the efficiency with which a hospital or firm turns its inputs into output, lowered by weak effort, motivation or management.
Z-Score
A z-score is the number of standard deviations a value lies above or below a reference mean, used in health economics to compare outcomes on one scale.