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.
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.
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-Study Heterogeneity
The genuine variation in true treatment effects across the studies in a meta-analysis, beyond what chance alone would explain.
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.
Big O Notation
An asymptotic notation that expresses an upper bound on how an algorithm?s resource use grows as input size increases, disregarding constant factors and lower-order terms.
Binary Representation
The encoding of numerical values using the binary number system, where all information is represented as combinations of 0s and 1s.
Binomial Distribution
A discrete probability distribution describing the number of successes in a fixed number of independent trials with the same success probability each.
Bisection Method
A numerical root-finding method that repeatedly halves an interval known to contain a root until the required level of accuracy is achieved.
Block Randomization
A randomisation technique assigning participants to groups in balanced blocks of a set size, keeping numbers roughly equal throughout enrolment.
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.
Bootstrapping Method
The specific procedure of repeatedly resampling, with replacement, from a dataset to empirically approximate the sampling distribution of a statistic of interest.
Bottom-Up Costing
A costing method that estimates total cost by measuring detailed resource use at the individual patient level and aggregating those measurements.
Break-Even Analysis
An analysis identifying the point at which the costs and benefits, or revenues, of an activity are equal.
Break-Even Point
The level of output or activity at which total revenue equals total cost, so an organisation neither gains nor loses money.
Breakeven Analysis
An analysis identifying the point at which total costs equal total revenues or benefits, so an activity neither gains nor loses value.
Brier Score
A measure of probabilistic prediction accuracy, the mean squared difference between predicted probabilities and actual observed binary outcomes, lower being better.
Budget Impact
The projected change in total spending for a payer or health system resulting from adopting a new treatment or policy.