Autoregressive Correlation
A statistical structure describing how repeated measurements on the same individual are correlated over time, closer measurements typically more strongly correlated.
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.
Average Cost-Effectiveness
A measure comparing an intervention's total cost to its total effect, without reference to an alternative comparator.
Average Cost-Effectiveness Ratio
The total cost of an intervention divided by its total health effect, calculated for each option rather than as a comparison.
Background Hazard
The rate of death from causes unrelated to the disease under study, applied to represent risk a patient would face regardless of the condition.
Bargaining Theory
A branch of economic theory analysing how parties negotiate to reach a mutually acceptable agreement when their interests partly conflict.
Bathtub Hazard
A hazard pattern that is high early in follow-up, declines to a stable middle period, then rises again later, resembling a bathtub's shape.
Baumol Effect
A phenomenon in which wages in labour-intensive, low-productivity-growth sectors rise alongside wages in high-productivity sectors, driving up the labour-intensive sector's relative cost.
Bayesian Analysis
A general statistical approach combining prior beliefs with observed data to produce updated posterior beliefs, unlike classical frequentist methods.
Bayesian Analysis CEA
The application of Bayesian statistical methods to cost-effectiveness analysis, combining prior beliefs with observed trial data to produce posterior distributions.
Bayesian Information Criterion
A statistic comparing candidate models fitted to the same data, similar to the Akaike criterion but penalising complexity more as sample size grows.
Bayesian Optimisation
A statistical approach updating probability estimates as new evidence arrives, used to combine prior information with observed trial data in modelling.
Benefit-Cost Ratio
The ratio of the monetised value of a programme's benefits to its costs, used as a summary measure in cost-benefit analysis.
Best-Worst Scaling
A stated preference method in which respondents identify both the most and least preferred items from a set, rather than ranking every item.
Beta Distribution
A flexible probability distribution bounded between zero and one, commonly used to represent uncertainty in probability parameters.
Beta Level
The predetermined acceptable probability of failing to detect a true effect, with one minus beta defining a study's statistical power.
Between-Subject Variation
The variability in an outcome measure observed across different individuals in a study, unlike within-subject variation in a single person's repeated measurements.
Bias-Variance Tradeoff
The tension in statistical modelling between a model's systematic error, or bias, and its sensitivity to the specific sample used to fit it, or variance.
Binomial Distribution
A discrete probability distribution describing the number of successes in a fixed number of independent trials with the same success probability each.
Bootstrap Standard Error
An estimate of a parameter's statistical uncertainty, calculated as the standard deviation of its value across many resampled datasets via bootstrapping.
Bootstrapping
A resampling technique estimating a statistic's sampling distribution by repeatedly drawing random samples, with replacement, from the original observed data.