Direct Elicitation
Direct elicitation is the valuation of a health state by asking people to trade it against life years or risk of death, rather than through a value set.
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.
Dirichlet Distribution
The Dirichlet distribution is a multivariate distribution for proportions that sum to one, used for uncertain transition probabilities from a model state.
Disability Weight
A disability weight is a value from 0 (full health) to 1 (equivalent to death) rating health loss in a non-fatal state, used to calculate YLDs and DALYs.
Disability-Adjusted Life Year
The disability-adjusted life year (DALY) measures health loss by adding years of life lost to premature death and years lived with disability.
Discount Factor
A discount factor is the weight below 1 that multiplies a cost or health effect in a future year to give its present value in economic evaluation.
Discount Rate
The discount rate is the annual rate, such as NICE's 3.5%, used in economic evaluation to convert future costs and health outcomes into present values.
Discounting
Discounting converts future costs and health effects, such as QALYs, into present values so that options with different timings can be compared.
Discrete Choice Experiment
A discrete choice experiment (DCE) is a survey where people choose between hypothetical health care options described by attributes, to measure trade-offs.
Discrete Data
Discrete data are values that can only be counted in whole steps, such as the number of hospital admissions, GP visits or exacerbations per patient.
Discrete Event Simulation
Discrete event simulation (DES) is a modelling method that follows each patient from event to event over time, tracking their history and use of resources.
Discrete Model
A discrete model represents at least one aspect of a system through distinct states, events, or time steps, allowing changes to be analysed as transitions among those elements rather than solely as continuously varying quantities.
Discriminant Validity
Discriminant validity is evidence that a health measure correlates less with measures of other constructs than with its own, as predicted in advance.
Disease-Free Survival
Disease-free survival (DFS) is the time from randomisation until cancer recurrence or death from any cause, an endpoint of adjuvant trials and models.
Distribution Fitting
Distribution fitting is choosing a probability distribution for a health economic model input, such as a cost or event time, and estimating its parameters.
Distribution-Based MID
A distribution-based MID is a minimal important difference estimated from score spread or instrument reliability, such as half a standard deviation.
Distributional Cost-Effectiveness
Distributional cost-effectiveness analysis (DCEA) is an economic evaluation showing who gains and loses health from a policy and its effect on inequality.
Distributional Weight
A distributional weight is a multiplier in cost-benefit analysis that values health policy gains and losses by who gets them, usually favouring the poor.
Disutility
Disutility is the loss of utility caused by a health state, adverse event or treatment, measured from a stated baseline and used to reduce QALYs.
DLQI
DLQI is a ten-question skin-specific quality of life questionnaire scored 0 to 30, used in dermatology trials and NICE appraisals to define response.
Dominance
Dominance in cost-effectiveness analysis excludes an option when another option, or a blend of two others, is no worse on cost or effect and better on one.