Dictionary

D

Direct Non-Medical CostTermNon-Medical Direct Cost, Carer Travel Cost

A direct cost borne by a patient or carer that is not itself a medical expense, such as transport to appointments.

Dirichlet DistributionConceptDirichlet Prior, Multivariate Proportion Distribution

The Dirichlet distribution is a multivariate distribution for proportions that sum to one, used for uncertain transition probabilities from a model state.

DisabilityTermReduced Functioning, Impairment-Based Limitation

A limitation in an individual's ability to perform activities or participate in life, arising from the interaction between a health condition and personal or environmental factors.

Disability WeightConceptDW, Severity Weighting Value

A disability weight is a value from 0 (full health) to 1 (equivalent to death) rating health loss in a non-fatal state, used to calculate YLDs and DALYs.

Disability-Adjusted Life YearConceptDALY, Disability Adjusted Life-Year

The disability-adjusted life year (DALY) measures health loss by adding years of life lost to premature death and years lived with disability.

Disability-Free ExpectancyTermDFLE, Disability-Free Life Expectancy

A summary population health measure expressing the average years an individual is expected to live without a disabling condition.

Disaggregate ModelTermSubgroup-Resolved Model, Patient-Level Model

A model that represents individual patients or small subgroups separately, rather than summarising the population using aggregate averages.

Discharge DispositionTermDischarge Destination, Discharge Setting

The specific destination a patient transitions to upon leaving hospital, such as home, a nursing facility, or hospice care.

Discharge InstructionsTermDischarge Advice, Patient Discharge Guidance

Written or verbal guidance given to a patient leaving a facility, detailing follow-up care, medication instructions, and warning signs to watch for.

Discharge ManagementTermDischarge Coordination, Hospital Exit Management

The processes an organisation uses to prepare and coordinate a patient's transition out of a hospital or facility.

Discharge PlanningTermDischarge Preparation, Care Transition Planning

The process of preparing a patient for transition out of a facility, assessing ongoing care needs and arranging follow-up services.

Discharge ProcessTermHospital Discharge, Discharge Workflow

The formal sequence of steps transitioning a patient out of hospital, covering final assessment, medication reconciliation, and follow-up arrangements.

DischargesTermInpatient Releases, Release Count

The total number of patients formally released from inpatient care within a facility over a defined period, a throughput measure.

DisclosureTermFormal Reporting, Interest Declaration

The formal reporting of information, such as a potential compliance violation or financial conflict of interest, to an appropriate authority.

Disclosure InterventionTermInformation Disclosure, Transparency Intervention

A policy requiring or encouraging the provision of information, such as nutrition labelling or price transparency, to influence decisions.

Disconnected NetworkTermUnconnected Evidence Network, Split Evidence Clusters

A situation where available trials do not link every treatment of interest through any chain of direct comparisons, leaving separate evidence clusters.

DiscountTermPurchaser Price Cut, Manufacturer Reduction

A reduction from a treatment's list price, negotiated between a manufacturer and a purchaser such as a payer or wholesaler.

Discount RateConceptAnnual Discount Percentage, Time-Value Rate, Discounting Rate

The discount rate is the annual rate, such as NICE's 3.5%, used in economic evaluation to convert future costs and health outcomes into present values.

Discount Rate SelectionTermChoosing the Discount Rate, Rate Justification

The methodological decision on which discount rate to apply in an economic evaluation, informed by the social opportunity cost of capital and relevant guidance.

DiscountingConcept

Discounting converts future costs and health effects, such as QALYs, into present values so that options with different timings can be compared.

Discounting CostsTermCost Discounting, Present-Valuing Costs

The application of a discount rate to future costs within an economic evaluation, converting them into a common present-day value.

Discounting HealthTermHealth Outcome Discounting, Present-Valuing Benefits

The application of a discount rate to future health outcomes within an economic evaluation, converting them into a common present-day value.

Discrete Choice ExperimentConceptDCE, Discrete-Choice Experiment, Choice Experiment

A discrete choice experiment, or DCE, presents respondents with repeated sets of hypothetical alternatives described by attributes and asks them to select a preferred option.

Discrete DataConceptCount Data

Discrete data are values that can only be counted in whole steps, such as the number of hospital admissions, GP visits or exacerbations per patient.

Discrete Event SimulationConceptDES, Event-Driven Simulation, Discrete Event Model

Discrete event simulation (DES) is a modelling method that follows each patient from event to event over time, tracking their history and use of resources.

Discrete ModelConceptDiscrete-Time Model, Fixed-Step Model

A discrete model represents at least one aspect of a system through distinct states, events, or time steps, allowing changes to be analysed as transitions among those elements rather than solely as continuously varying quantities.

Discriminant ValidityConceptDivergent Validity, Discriminant Construct Validity

Discriminant validity is evidence that a health measure correlates less with measures of other constructs than with its own, as predicted in advance.

DiscriminationTermPredictive Separation, Outcome Distinguishing

The ability of a predictive model or diagnostic test to correctly distinguish between individuals who will and will not experience an outcome.

Discrimination AssessmentTermDiscrimination Evaluation, Discriminative Performance Assessment

An evaluation of a predictive model's ability to distinguish between individuals who will and will not experience a given outcome, often via the ROC curve.

Discrimination BarrierTermDiscriminatory Barrier, Bias-Based Access Barrier

An obstacle to healthcare arising from unfair treatment based on characteristics such as race, ethnicity, or disability, rather than clinical need.

Disease BurdenTermTotal Disease Impact, Population Disease Impact

The total impact of a disease on a population, covering mortality, morbidity, and costs, commonly quantified using disability-adjusted life years.

Disease Control RateTermDCR, Non-Progression Proportion

A cancer outcome measure combining complete response, partial response, and stable disease rates, characterising the proportion whose disease did not progress.

Disease ManagementTermChronic Condition Management, Condition Management Programme

A coordinated programme of interventions improving outcomes for patients with a specific chronic condition, combining education, coordination, and monitoring.

Disease PathwayTermDisease Course, Clinical Course Sequence

The sequence of clinical states and events patients with a given condition typically experience over time, from diagnosis through outcome.

Disease PreventionTermIllness Prevention, Prevention of Disease

Actions taken to reduce the likelihood a disease will occur, progress, or cause complications, covering primary, secondary, and tertiary approaches.

Disease ProgressionTermTumour Growth Progression, Disease Worsening

An increase in tumour size or the appearance of new lesions during or after treatment, indicating the treatment no longer adequately controls the disease.

Disease Severity ClassificationTermSeverity Grading, Severity Categorisation

A formal system categorising disease severity, used within some assessment frameworks to apply differential weighting or thresholds accordingly.

Disease SurveillanceTermEpidemiological Surveillance, Outbreak Monitoring

The ongoing, systematic collection and analysis of health data to monitor disease occurrence and spread within a population, detecting outbreaks.

Disease-Free SurvivalConceptDFS

Disease-free survival (DFS) is the time from randomisation until cancer recurrence or death from any cause, an endpoint of adjuvant trials and models.

Disease-Modifying TherapyTermDMT, Course-Altering Treatment

A treatment altering a disease's underlying course or progression, rather than merely treating symptoms, such as certain multiple sclerosis treatments.

Disease-Specific InstrumentTermDisease-Targeted Measure, Disease-Specific Questionnaire, Condition-Specific Measure, Disease-Specific Measure, Condition-Specific Instrument

A health status questionnaire capturing outcomes and symptoms relevant to a particular condition, more sensitive to change than a generic instrument.

Disease-Specific QoLTermDisease-Specific Quality of Life, Condition-Specific QoL

A quality of life measure capturing aspects of wellbeing most affected by a particular disease, such as its specific symptom burden.

Diseconomies of ScaleTermRising Average Cost, Scale Inefficiency

A situation in which average cost of production rises as output increases, often due to coordination difficulties or capacity constraints.

DisinvestmentTermDivestment, Funding Withdrawal

The deliberate withdrawal of funding from a healthcare service or technology found to provide low value or since superseded by a better alternative.

Disinvestment FrameworkTermDivestment Framework, Withdrawal Methodology

A structured methodology for identifying, evaluating, and implementing the withdrawal of funding from low-value healthcare services or technologies.

Dispensing PracticeTermMedicine Dispensing, Dispensing Activity

The activities involved in preparing and providing a medication to a patient per a valid prescription, covering verification, preparation, and counselling.

DispersionTermVariability, Spread

A statistical concept describing how spread out or clustered values in a dataset are, commonly measured using variance, standard deviation, or interquartile range.

DisplacementTermForgone Health, Health Opportunity Loss, Displacement Effect

The loss of health benefit elsewhere in a health system that results from allocating resources to a new treatment.

Disproportionate ShareTermDSH, Safety-Net Hospital Payment

A US Medicaid funding mechanism providing additional payments to hospitals serving a disproportionately large share of low-income and uninsured patients.

Disruptive InnovationTermMarket-Disrupting Innovation, Displacing Innovation, Disruptive Technology

An innovation creating a new market by initially serving an overlooked segment with a simpler or cheaper offering, eventually displacing established competitors.