Dictionary

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Constrained OptimisationConceptConstrained Optimization, Bounded Optimisation

Constrained optimisation finds the choice that does best on an objective, such as QALYs gained, without breaking limits such as a fixed health budget.

Construct ValidityConceptConstruct Soundness, Theoretical-Concept Validity

Construct validity is how well a PROM's scores fit hypotheses about it, covering structural validity, hypotheses testing and cross-cultural validity.

Consumer AssessmentTermConsumer Survey, Patient Perspective Survey

A standardised survey methodology measuring patients' or consumers' perspectives on care received, covering communication quality and timeliness.

Consumer ChoiceConceptConsumer Selection, Consumer Decision-Making

Consumer choice is the economic theory of how people choose goods and services, including health care, to best satisfy their preferences within a budget.

Consumer Price IndexConceptCPI, Consumer Price Measure

The consumer price index (CPI) measures change in the prices households pay for a fixed basket of goods and services, used to adjust costs for inflation.

Consumer SurplusConceptConsumer's Surplus, Buyer Surplus

Consumer surplus is the most that buyers would pay for a good or service minus what they pay, measured as the area under the demand curve above the price.

Consumer-Directed Health PlanConceptCDHP, High-Deductible Consumer Plan

A consumer-directed health plan (CDHP) is a US health plan pairing a high deductible with a tax-favoured account, such as an HSA or HRA, to pay for care.

Contact CoverageTermPopulation Contact Reach, First-Contact Uptake

A measure of the proportion of a target population that has received at least one contact with a specific service, an early coverage step.

Contact RateConceptContact Frequency, Mixing Rate

Contact rate is the expected number of defined, potentially transmission-relevant encounters an individual has per unit time in an infectious-disease model.

Contact TracingConceptExposure Tracing, Case Contact Follow-Up

Contact tracing finds and follows up people exposed to an infectious case so they can be tested, treated or quarantined before infecting others.

ContaminationConcept

Contamination occurs when trial participants receive the other arm's intervention, usually controls getting the new one, diluting the measured effect.

Content ValidityConceptContent Soundness, Domain Representativeness

Content validity is how far a health measure's items are relevant, comprehensive and understood for its construct, target population and context of use.

ContextualizationTermContextualisation, Evidence Adaptation to Setting

The process of interpreting and adapting external evidence to reflect the specific clinical, economic, and organisational context of a decision-making body.

Contingency FeeTermContingent Fee, Recovery-Based Fee

A payment structure in which a contractor is compensated based on a percentage of funds recovered through auditing, rather than a fixed fee.

Contingency TableConcept2x2 Table, Two-by-Two Table, Cross-Tabulation

A contingency table counts observations cross-classified by two or more categorical variables, such as trial arm by outcome or test result by disease.

Contingent ValuationConceptCV Survey, Stated WTP Survey

Contingent valuation (CV) is a stated preference survey method asking people what they would pay for, or accept to give up, a described change in health.

Contingent Valuation MethodConceptCVM, Stated-Preference Valuation

The contingent valuation method elicits a monetary value for a specified nonmarket health-related change by asking people what they would pay or accept in a carefully described hypothetical scenario.

Continuity DesignTermCoverage Continuity Provisions, Transition Protection

Provisions within an insurance plan intended to ensure enrollees maintain uninterrupted coverage and access to existing providers when transitioning between plans.

Continuity of CareConceptCare Continuity, Continuous Care Relationship

Continuity of care is the extent to which a patient's care over time is joined up, through a known clinician, shared information or a consistent plan.

Continuous CoverageConceptUninterrupted Coverage, Gap-Free Coverage

Continuous coverage is health insurance held with no gap longer than a set limit, often 63 days in US law, which can shorten pre-existing exclusions.

Continuous DataConcept

Continuous data are outcomes measured on a numerical scale that can take any value within a range, such as blood pressure, cost or utility.

Continuous Glucose MonitoringTermCGM, Real-Time Glucose Monitoring

A diabetes technology continuously tracking blood glucose through a sensor, giving more comprehensive data than periodic fingerstick testing.

Continuous ModelConceptContinuous-Time Model, Differential-Equation Model

A continuous model is a decision model run in continuous time rather than fixed cycles, so health events can occur at any moment, governed by rates.

Continuous Quality ImprovementConceptCQI, Kaizen in Healthcare

Continuous quality improvement (CQI) is an approach in which health services use systematic data and repeated tests of change to improve care.

Contract TheoryConceptTheory of Contracts, Agency Contract Design

Contract theory studies how contracts, such as provider payment rules, can align incentives when actions or information are hidden or cannot be verified.

ContraindicationTermTreatment Exclusion Criterion, Do-Not-Use Condition

A specific patient condition or characteristic making a particular treatment inadvisable or potentially harmful for them to receive.

Control ArmConceptTrial Control Group, Comparison Arm, Control Group

A control arm is the trial group given placebo, no treatment, another dose or another treatment, against which outcomes on the new treatment are compared.

Control ChartConceptShewhart Chart, SPC Chart

A control chart is a time-series plot of a health service measure with a centre line and control limits that separate routine variation from real change.

Control Chart AnalysisTermControl Chart Interpretation, SPC Interpretation

The process of interpreting a control chart to determine whether observed variation reflects normal fluctuation or a significant change requiring action.

Control VariatesConceptControl Variate Method, Variance Reduction via Controls

Control variates is a variance reduction method that corrects a Monte Carlo estimate, such as mean cost or QALYs, using a correlated output of known mean.

Controllable CostConceptManageable Cost, Manager-Influenced Cost

Controllable cost is a health service cost that a named budget holder can influence within the budget period, such as ward overtime or agency staffing.

Convenience OutcomeTermConvenience Endpoint, Administration-Burden Outcome

A clinical outcome measure capturing the ease or burden of a treatment's administration, such as dosing frequency, distinct from its clinical efficacy.

ConvergenceConceptIterative Stabilisation, Algorithm Settling

Convergence is the point at which an MCMC run or other iterative simulation settles on a stable result as the number of iterations increases.

Convergence AssessmentTermConvergence Diagnostics, MCMC Diagnostics

An evaluation of whether an iterative algorithm, such as a Markov chain Monte Carlo simulation, has run enough iterations to produce stable results.

Convergent ValidityConceptConvergent Validation

Convergent validity is evidence that a health measure correlates, as predicted in advance, with other measures of the same or a closely related construct.

Conversion FactorConceptCF

Conversion factor (CF) is the money amount per relative value unit that turns fee schedule relative values, such as Medicare RVUs, into payment amounts.

Cook's DistanceConceptCook Distance, Influence Statistic

Cook's distance is a regression diagnostic measuring how much all fitted values change when one observation, such as one patient's cost record, is removed.

Cooling Off InterventionTermCooling-Off Period, Mandatory Delay

A policy mechanism imposing a mandatory delay before a decision becomes final, meant to reduce impulsive choices made under pressure.

Coordinated Care ModelTermCare Coordination Model, Integrated Delivery Model

A delivery approach deliberately organising patient care activities among multiple participants to facilitate appropriate, timely service delivery across settings.

Copas ModelConceptCopas Selection Model, Publication Bias Model

The Copas model is a selection model for publication bias in meta-analysis that re-estimates the pooled effect under assumed rates of non-publication.

CopaymentConceptCopay, Fixed Fee Cost-Share, Copay Amount, Fixed Copay Charge

A copayment (copay) is a fixed amount an insured person pays for a covered health service, such as USD 20 per visit, unlike percentage-based coinsurance.

COPD Assessment TestConceptCAT, Chronic Airways Assessment Test, CAAT

COPD Assessment Test (CAT) is an eight-item patient questionnaire, scored 0 to 40, on how COPD affects health status, used in trials and GOLD assessment.

Coping StrategyTermHousehold Financial Response, Expense Coping

An action a household takes to manage the financial burden of a healthcare expense, such as borrowing, selling assets, or reducing spending.

Copy ReferenceTermCopy-Reference Imputation, Reference-Based Imputation

A missing data method, often used after treatment discontinuation, assuming a patient's future outcomes follow the trajectory observed in the reference arm.

Core MeasureTermCore Quality Measure, Standardised Care Indicator

A standardised, evidence-based process of care indicator established as a minimum quality expectation for a specific clinical condition.

Core Measure ComplianceTermCore Measure Adherence, Core-Measure Conformance

The degree to which an organisation adheres to a standardised set of evidence-based care processes established as minimum quality expectations.

Core Outcome SetConceptCOS

Core outcome set (COS) is the agreed minimum set of outcomes all trials in a condition should measure and report, so results can be compared and combined.

Core Outcome Set DevelopmentConceptCOS Development, COS Development Study

Core outcome set development is the consensus study, usually a review, Delphi and meeting, agreeing what trials in a condition should measure and report.

Core Value MessageTermCentral Value Claim, Key Value Message

The central, most important claim a manufacturer wishes to communicate regarding a technology's value proposition, forming the foundation for further materials.

Coronary Artery Bypass GraftingTermCABG, Bypass Surgery

A surgical procedure rerouting blood flow around blocked coronary arteries using a graft vessel taken from elsewhere, treating severe coronary artery disease.