Age Weighting
An early methodological adjustment to the DALY calculation valuing healthy years lived in young to middle adulthood more highly than years in childhood or old age.
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.
Agent-Based Model
A simulation approach representing individual entities, such as patients or providers, as autonomous agents following behavioural rules, letting system patterns emerge.
Aggregate Data Meta-Analysis
A technique combining summary results, such as reported means or event rates, from multiple studies into a single pooled estimate.
Aggregate Stop-Loss
A form of reinsurance protecting a self-insured employer against total claims across its covered population exceeding a predefined threshold.
Akaike Information Criterion
A statistic comparing the relative quality of candidate statistical models fitted to the same data, penalising those with more parameters.
Allocative Efficiency
A condition in which resources are distributed among competing uses to maximise total value, given fixed technical efficiency in production.
Alpha Spending
A group sequential trial method allocating the overall acceptable risk of a false positive across multiple planned interim analyses.
Annuity Payment
A reimbursement structure paying a treatment's total cost to the manufacturer in a series of instalments over time, rather than as a single upfront sum.
Antithetic Variates
A variance reduction technique pairing each sampled value with a negatively correlated complementary value to reduce a simulation's output variance.
Area Under Curve
A summary statistic representing a predictive model's discriminative ability, the area beneath its ROC curve, from 0.5 for chance to 1 for perfect.
Area Under Curve Approach
A survival extrapolation method fitting a parametric distribution to observed data and calculating the area under the resulting curve to estimate mean survival.
Arrival Process
The pattern by which entities, such as patients, enter a discrete event simulation over time, governed by a probability distribution of intervals.
Asymptotic Normality
A statistical property whereby, as sample size grows large, an estimator's sampling distribution approaches a normal distribution regardless of the original data's shape.
Atkinson Index
A measure of income or health inequality incorporating an explicit parameter reflecting society's aversion to inequality at the bottom of the distribution.
Attachment Point
The specific threshold at which a stop-loss or reinsurance policy begins covering costs, with the insured responsible for costs below it.
Attack Rate
A measure of disease incidence in a specific outbreak, the proportion of an at-risk population that develops the disease over the outbreak period.
Attack Rate Ratio
A measure comparing the attack rate of a disease between two groups within an outbreak, such as those exposed and unexposed to a source.
Attributable Fraction
The proportion of disease cases within a population that would not have occurred without a specific exposure, showing its public health impact.
Attributable Risk
The difference in risk of an outcome between an exposed group and an unexposed group, the portion attributable to the exposure itself.
Autoregressive Correlation
A statistical structure describing how repeated measurements on the same individual are correlated over time, closer measurements typically more strongly correlated.