Median
A central tendency measure representing the middle value of an ordered dataset, dividing it into two equal halves.
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.
Mediation Analysis
A statistical approach examining whether an exposure's effect on an outcome operates through an intermediate variable, called a mediator, rather than directly.
Meta-Analysis
A statistical technique combining the quantitative results of multiple independent studies addressing the same question into a single, more precise estimate.
Method of Moments
A technique estimating a distribution's parameters by equating sample moments, such as mean and variance, to their theoretical population equivalents.
Minimal Clinically Important Difference
The smallest change in an outcome measure that patients or clinicians would consider meaningful, used to judge whether a statistically significant result matters clinically.
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.
Missing at Random
A missing data classification indicating the probability of a value being missing depends on other observed variables, not the missing value itself.
Missing Completely at Random
A missing data classification indicating the probability of missingness is entirely unrelated to any observed or unobserved variables, the strongest assumption.
Missing Not at Random
A missing data classification indicating the probability of missingness depends on the unobserved value itself, even after accounting for other variables.
Mixed Effects Model
A modelling approach including both fixed effects for average relationships and random effects for individual variation, suited to nested or repeated data.
Mixed Model Repeated Measures
A longitudinal trial analysis method using a mixed effects framework under the missing at random assumption, an alternative to last observation carried forward.
Mixed Treatment Comparison
An earlier term for network meta-analysis, describing the statistical combination of direct and indirect evidence across a connected treatment network.
Mode
A central tendency measure representing the most frequently occurring value within a dataset.
Moderation Analysis
A statistical approach examining whether an exposure-outcome relationship's strength or direction differs depending on the level of a third, moderating variable.
Multicollinearity
A condition in which two or more regression predictors are highly correlated with one another, making individual effect estimates unreliable.
Multilevel Model
A model representing nested data, such as patients within hospitals within regions, allowing relationships to vary at each level while sharing strength.
Multiple Imputation
A missing data technique generating several plausible complete datasets with different estimated replacement values, then combining separate analyses of each.
Multivariate Meta-Analysis
A meta-analysis method jointly analysing two or more related outcomes simultaneously, accounting for the correlation between them.
N-of-1 Trial
A trial conducted within a single participant, repeatedly alternating experimental treatment and control in random, blinded sequence to determine its individual effect.
Negative Binomial
A discrete probability distribution modelling count data with more variability than a Poisson distribution would predict, known as overdispersion.