Dictionary

L

Log-Logistic ModelConceptLoglogistic Regression Model, Fisk Survival Model

A survival model based on the log-logistic distribution, representing a hazard function that rises to a peak and then declines.

Log-Normal DistributionConceptLognormal Distribution, Galton Distribution

A probability distribution in which the logarithm of the variable follows a normal distribution, often used for hazards that rise then fall.

Log-Normal ModelConceptLognormal Survival Model, Lognormal AFT

A survival model based on the log-normal distribution, capable of representing a hazard that rises then falls, similar in shape to log-logistic.

Log-Rank TestConceptMantel-Cox Test, Mantel-Haenszel Survival Test

The log-rank test is a nonparametric hypothesis test that compares the event-time distributions of two or more groups by accumulating observed-minus-expected events across distinct event times while accounting for right censoring.

Logarithmic PoolConceptLogarithmic Opinion Pool, Geometric Opinion Pool

A method combining multiple experts' probability distributions by taking a weighted geometric average rather than a simple arithmetic average.

Logic ModelTermProgramme Logic, Results Chain

A visual diagram illustrating the logical relationships between a programme's resources, planned activities, and expected short-, intermediate-, and long-term outcomes.

Logistic RegressionConceptLogit Regression, Binary Logistic Model

A modelling technique estimating the relationship between predictor variables and a binary outcome, expressing results as odds ratios.

Long-Term Acute Care HospitalTermLTACH, Long-Stay Acute Hospital

A specialist hospital providing extended-duration, intensive medical care for patients needing longer recovery than a standard acute stay allows.

Long-Term CareTermLTC, Continuing Care

Ongoing support and personal care for people with chronic illness, disability, or age-related functional decline, spanning home and residential settings.

Long-Term Care CostTermLTC Cost, Continuing Care Expense

The expense of ongoing support services for people with chronic illness, disability, or age-related decline, spanning home-based and residential settings.

Long-Term Care EconomicsConceptLTC Economics, Aged Care Economics

The study of resources, financing, incentives and outcomes involved in sustained formal and unpaid support for people with ongoing care needs.

Long-Term OutcomeTermLong-Term Result, Extended-Horizon Outcome

A clinical or economic outcome observed or projected over an extended time horizon, often beyond a trial's observed follow-up period.

Longitudinal DataTermRepeated-Measures Data, Follow-Up Data

Data collected on the same individuals repeatedly over time, allowing observation of change and the timing between exposures and outcomes.

Longitudinal DesignConceptLongitudinal Study Design, Follow-Up Design

A longitudinal design observes the same individuals or other study units at multiple time points to characterize within-unit change, temporal sequence, and differences in trajectories over time.

Longitudinal MethodsTermLongitudinal Analysis, Panel Methods

Statistical techniques designed to analyse data collected repeatedly on the same individuals over time, accounting for correlation among repeated measurements.

Lookup TableTermReference Table, Precomputed Value Table

A data structure storing precomputed values, such as mortality rates or unit costs, indexed for quick retrieval within a health economic model.

Lorenz CurveConceptLorenz Diagram, Cumulative Distribution Curve

A graph plotting the cumulative share of total income against the cumulative share of population, ranked poorest to richest, showing distribution.

Loss Aversion ConceptTermLoss Aversion, Asymmetric Value Perception

The principle that losses are weighted more heavily in decision-making than equivalent gains, a core part of prospect theory.

Loss of ResponseTermSecondary Non-Response, Treatment Escape

A clinical outcome indicating a patient who previously achieved a favourable response later experiences a return of disease activity or decline in response.

Loss to Follow-UpConceptLost to Follow-Up

Loss to follow-up occurs when trial participants stop providing data before follow-up ends, so later outcomes, costs and QALYs can be missing.

Low Performer IdentificationTermUnderperformer Detection, Low-Outlier Flagging

The process of systematically identifying providers whose performance falls notably below relevant benchmarks, to prioritise targeted improvement support.

Low-Income CountryTermLIC, Low-Income Economy

A country classified by gross national income per capita as falling within the lowest tier of an international income classification system.

Low-Income SubsidyTermExtra Help Subsidy, Part D Low-Income Assistance

Financial assistance reducing the cost of health insurance or healthcare specifically for individuals or households with limited resources.

Low-Quality EvidenceTermLow-Certainty Evidence, Weak Evidence

Within GRADE, a rating indicating limited confidence that the true effect matches the reported estimate, typically from observational or flawed studies.

Low-Value CareTermLow-Value Service, Wasteful Care

Healthcare services providing little or no clinical benefit relative to cost, or carrying harm risk exceeding likely benefit.

LTACH DischargeTermLong-Term Acute Care Release, Step-Down Transfer

The conclusion of a patient's stay at a long-term acute care hospital, transitioning to a lower level of care or elsewhere.

Lung Cancer ScreeningTermLDCT Screening, Pulmonary Cancer Screening

A public health strategy using low-dose CT imaging to detect lung cancer in individuals with a significant smoking history, at an earlier stage.

Lupus EconomicsTermSLE Economics, Systemic Lupus Erythematosus Cost

The application of health economic evaluation to systemic lupus erythematosus, a chronic autoimmune condition with unpredictable flares affecting multiple organs.