Minimal Important Difference
The smallest change in a health outcome measure a patient would perceive as beneficial, or that would prompt a clinician to change management.
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.
Minimal Residual Disease
The small amount of disease still detectable using highly sensitive techniques after treatment appears, by less sensitive measures, to have achieved complete response.
Minimally Important Difference
The threshold change in a health outcome score considered meaningful, estimated using either anchor-based or distribution-based methods.
Mortality Rate
A measure of death frequency within a defined population over a specified period, typically expressed per thousand or per hundred thousand people.
Multi-Attribute Utility
A utility value derived by combining preference weights across several distinct attributes of an outcome into a single overall measure.
Multi-State Life Table
A life table method modelling a population's transitions among several health states, including recovery as well as decline, over successive age intervals.
Observed-to-Expected Ratio
A measure comparing a provider's actual observed outcomes against statistically expected numbers given patient severity, above one meaning worse than expected.
Ordinal Scaling
A measurement scale property in which values can be ranked but numerical differences do not necessarily reflect equal differences in the underlying quantity.
Paired Comparison
A health state valuation method in which respondents are shown two states at a time and indicate which they prefer, building up a ranking.
Patient Outcome
A measurable change in health, function, symptoms, quality of life or survival experienced by a patient.
Preference Weight
A numerical value reflecting the relative desirability a population or individual assigns to a particular health state or outcome.
Process Capability
A statistical measure of how consistently a process produces output within specified acceptable limits, assessing whether it reliably meets targets.
Proportional Shortfall
A measure of disease severity calculated as the proportion, rather than absolute number, of expected quality-adjusted life years lost to a condition.
QALY Calculation Method
The process of computing quality-adjusted life years by multiplying time spent in a health state by its utility value, then summing across states.
QALY Gain
The increase in quality-adjusted life years attributable to an intervention, the difference between the QALYs expected under it and its comparator.
Quality-Adjusted Life Year (QALY)
A quality-adjusted life year combines time lived with preference-based health-state values so that one year at utility 1 represents one QALY, while periods in poorer health contribute proportionately less—or negatively where the applicable value set permits states valued below dead.
Quality-Adjusted Time Without Symptoms
An oncology outcome measure, Q-TWiST, dividing survival into phases, such as toxicity, symptom-free time, and time after relapse, each weighted by quality of life.
Readmission Rate
A measure of the proportion of patients readmitted to hospital within a defined period, commonly thirty days, after a prior discharge.
Relapse-Free Survival
A time-to-event measure defined as the time from treatment completion until disease recurrence or death, used for curative-intent treatments.
Responsiveness
The ability of a health outcome measure to detect a clinically meaningful change in health status over time when one has genuinely occurred.