Skewness
Skewness measures the asymmetry of a distribution around its mean, such as the long right tail that a few very costly patients give health care cost data.
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.
Sobol Indices
Sobol indices are variance-based sensitivity measures giving the share of a health economic model output's variance due to each input and its interactions.
Sobol Sequence
A Sobol sequence is a deterministic low-discrepancy sequence that spreads parameter values evenly for quasi-Monte Carlo runs of health economic models.
Social Choice Theory
Social choice theory is the study of rules that combine individual preferences or judgements into one collective decision, such as a health care priority.
Social Opportunity Cost of Capital
The social opportunity cost of capital is the opportunity cost of public funds, the return on private investment that projects such as hospitals displace.
Social Return on Investment
Social return on investment (SROI) values a programme's health, social and environmental outcomes in money and compares the total with what it cost.
Social Welfare Function
A social welfare function (SWF) combines individual health or wellbeing into overall social welfare, setting how equality is weighed against the total.
Societal Perspective
The societal perspective is an economic evaluation viewpoint that counts all costs and outcomes, whoever bears them, including productivity and carer time.
Spearman Correlation
Spearman correlation is a rank-based measure from -1 to +1 of how consistently two variables, such as disease severity and costs, rise or fall together.
Spline Model
A spline model is a regression model that joins polynomial pieces at knots to fit a flexible curve, such as hospital cost by age or survival over time.
Standard Costing
Standard costing sets the expected cost of a health service in advance from standard quantities and prices, then compares actual costs with this benchmark.
Standard Deviation
Standard deviation is a measure of how widely patient costs, outcomes or other values spread around their mean, in the same units as the data.
Standard Error
The standard error (SE) is the standard deviation of an estimate's sampling distribution, showing how precisely a mean cost or treatment effect is known.
Standard Normal
The standard normal distribution is a normal distribution with mean 0 and standard deviation 1, used in health economics to read z values as probabilities.
Standardised Mean Difference
The standardised mean difference (SMD) is a mean difference divided by a standard deviation, used to pool continuous outcomes measured on different scales.
Standardised Residual
A standardised residual is a regression residual divided by its estimated standard deviation, used to flag outlying patients in cost and outcome models.
State Occupancy
State occupancy is the expected time a modelled cohort spends in a health state, found by adding the share of the cohort in that state across model cycles.
State Reward
A cost, utility, health outcome, or other consequence accrued while a modelled person occupies a specified state for a defined amount of time.
State Space Model
A state space model is a time series model where hidden states, such as disease severity or service demand, evolve over time and are measured with error.
State Transition Model
A state transition model is a decision model in which a cohort or simulated patients move between health states over time to estimate costs and QALYs.