Sensitivity to Change
The capacity of a health outcome measure to register a difference in health status when a real change has occurred in a patient's condition.
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.
Single Attribute Utility
A utility value derived from a single dimension of health or outcome, unlike multi-attribute utility, which integrates several dimensions.
Standard Gamble
A health state valuation method in which respondents choose between a defined health state with certainty or a gamble between full health and death.
Standardised Mortality Ratio
A measure comparing actual deaths observed within a population against statistically expected deaths given its risk characteristics, above one meaning worse.
Standardised Response Mean
A responsiveness statistic calculated as the mean score change over time divided by the standard deviation of that change, unlike an effect size.
Statistical Process Control
A quality management method using statistical techniques to monitor a process, distinguishing normal variation from a genuine, significant change requiring action.
Stochastic Frontier Analysis
A parametric method estimating relative efficiency of comparable units by modelling an efficiency frontier while accounting for random statistical noise.
Sullivan Method
A technique for calculating health expectancy measures by combining age-specific mortality rates from a life table with age-specific prevalence rates of disability.
Symptom-Free Survival
A time-to-event measure defined as the time from treatment start until the onset or return of clinically significant symptoms.
Tariff
The specific set of utility weights, derived from a population valuation study, used to convert health status instrument responses into a single score.
Time Trade-Off
A health state valuation method asking how many years in full health a respondent would consider equal to a longer period in an impaired state.
Time Without Symptoms of Progression
A phase within the Q-TWiST framework covering the period free of significant treatment toxicity or disease progression symptoms, typically weighted highest.
Utilisation Rate
A measure of how frequently a service or resource is used within a population, typically expressed relative to population size.
Utility
A numerical representation of the satisfaction, wellbeing, or preference an individual derives from a particular outcome, state, or good.
Value Set
The complete collection of utility weights from a population valuation study, used to convert every combination of instrument responses into a utility score.
Value Set Development
The process of designing, conducting, and analysing a population valuation study to produce a scoring algorithm for a health status instrument.
Variation
Differences observed in a healthcare process or outcome across patients, providers, or time periods, either legitimate or reflecting inconsistent quality.
Visual Analogue Scale
A health state valuation method in which respondents mark a perceived health state on a continuous line anchored between worst and best imaginable health.
Years Lived with Disability
A component of the disability-adjusted life year representing healthy years lost to a non-fatal condition, found by multiplying its prevalence by its disability weight.
Years of Life Lost
A premature mortality measure calculated as the difference between age at death and a reference life expectancy, summed across deaths from a cause.