Dictionary

W

Waiting ListTermWait List, Queue

An ordered list of patients awaiting a healthcare service, such as elective surgery, that exceeds available capacity to provide it.

Waiting List ManagementTermWait List Management, List Prioritisation

The strategies used to organise, prioritise, and monitor patients awaiting access to a limited healthcare resource, such as elective surgery.

Waiting TimeTermWait Time, Time to Treatment

The interval between a patient's referral for a service and the point at which they actually receive it, a responsiveness indicator.

Waiver of ConsentTermConsent Waiver, Waived Consent

A regulatory determination permitting research to proceed without standard informed consent under narrowly defined conditions, such as minimal risk studies.

Wald TestConceptWald Statistic, Wald Chi-Square Test

A statistical test assessing whether an estimated parameter differs significantly from a specified value, based on the ratio of estimate to standard error.

Warm-Up PeriodTermBurn-In Period, Initialisation Bias Period

An initial portion of a discrete event simulation run excluded from results, letting the system reach a representative state before data collection begins.

Warranted VariationTermJustified Variation, Appropriate Variation

Differences in utilisation or practice that appropriately reflect legitimate differences in patient illness or informed preference, unlike unwarranted variation.

Washout PeriodTermWash-Out Period, Clearance Period

A period with no treatment given in a crossover trial between two active phases, letting the first treatment's effects fully dissipate.

Waste in HealthcareTermHealthcare Waste, Wasteful Spending

Healthcare spending that does not contribute to improving patient health, covering administrative waste, clinical waste, and operational inefficiency.

Watchful WaitingTermExpectant Management, Conservative Monitoring

A management approach for slow-growing or low-risk conditions involving close monitoring over time without immediate active treatment.

Weak DominanceConceptNon-Strict Dominance, Weakly Dominated Option

Weak dominance is when another option costs no more and is at least as effective, and is strictly better on one, so the dominated option is dropped.

Weak RecommendationTermGrade 2 Recommendation, Qualified Recommendation, Conditional Recommendation, Discretionary Recommendation, Conditional GRADE Recommendation

Within GRADE, a conditional recommendation indicating benefits probably outweigh harms with less certainty, so patients might reasonably choose differently.

Wearable DataTermWearable Sensor Data, Device-Generated Data

Health-related information collected through devices such as fitness trackers or glucose monitors, capturing physiological measures continuously over time.

Wearable DeviceTermWearable Device Health, Health Wearable

An electronic device worn on the body, such as a smartwatch, capable of continuously monitoring physiological parameters such as heart rate.

Weibull DistributionConceptWeibull Probability Distribution, Weibull Density

A flexible probability distribution capable of a monotonically increasing or decreasing hazard rate depending on its shape parameter.

Weibull ModelConceptWeibull Survival Model, Weibull Regression

A survival model based on the Weibull distribution, representing an increasing or decreasing hazard over time, though restricted to a monotonic pattern.

Weight ManagementTermWeight Control, Weight Loss Programme

A clinical and behavioural approach to achieving and maintaining a healthy body weight, combining dietary counselling, activity guidance, and sometimes drug or surgical treatment.

Weighted Least Squares RegressionConceptWeighted Least Squares, WLS

Weighted least squares (WLS) is regression that weights each squared residual, ideally by the inverse of its error variance, as in meta-analysis for HTA.

Weighted Log-RankConceptWeighted Rank Test, G-Rho Family Test

A survival-curve comparison test that weights each event-time observed-minus-expected count to emphasize a prespecified pattern of differences over follow-up.

Weighting DesignTermSurvey Weighting, Sampling Weight Design

A study design element specifying how observations should be weighted to account for unequal sampling probabilities or non-response, representing the target population.

Welfare EconomicsConceptWelfarism, Welfare Theory

Welfare economics is the normative branch of economics that judges whether changes in the allocation of resources and health make society better off.

Welfare TheoremTermFundamental Theorems of Welfare, Efficiency-Equilibrium Theorem

Either of two foundational results linking competitive market equilibrium to Pareto efficiency, given appropriate initial resource redistribution.

WellbeingTermWell-Being, Life Satisfaction

A broad concept covering an individual's overall state of comfort, health, and happiness, of which health-related quality of life is one part.

Wellbeing or Capability InstrumentConceptCapability Instrument, Wellbeing Instrument, Capability Wellbeing Measure

Wellbeing or capability instruments are outcome measures, such as ICECAP, WEMWBS or EQ-HWB, that capture benefits beyond health that EQ-5D QALYs miss.

WEMWBSConceptWarwick-Edinburgh Mental Wellbeing Scale, Warwick-Edinburgh Mental Well-being Scale

WEMWBS is the Warwick-Edinburgh Mental Wellbeing Scale, a 14-item measure of positive mental wellbeing used as an outcome in public health evaluations.

WhistleblowerTermWhistle-Blower, Disclosure of Wrongdoing

An individual reporting suspected fraud, compliance violations, or misconduct within an organisation to an appropriate authority, sometimes via a lawsuit.

White Box ModelTermTransparent Model, Glass-Box Model

A model whose complete internal structure, assumptions, and calculations are fully transparent and accessible to external reviewers, the opposite of a black box.

WHOTermWorld Health Organization, World Health Organisation

The World Health Organization, a United Nations agency coordinating international public health efforts and setting global health standards.

Whole-of-GovernmentTermJoined-Up Government, Cross-Departmental Action

A policy approach where multiple government departments work collaboratively across sectoral boundaries to address a shared objective, such as population health.

Whole-of-SocietyTermMultisectoral Engagement, All-of-Society Action

A policy approach engaging government, civil society, the private sector, and communities collaboratively toward a shared health objective.

WHOQOL-BREFConceptWorld Health Organization Quality of Life-BREF, WHOQOL Brief

WHOQOL-BREF is the WHO's 26-item generic quality of life questionnaire with four domain scores, used as a trial outcome but not as a QALY utility.

Wilcoxon TestConceptWilcoxon Rank-Sum Test

A test comparing survival distributions that gives greater weight to earlier event times than later ones, unlike the standard log-rank test.

Willingness to AcceptConceptWTA, Compensation Demanded

The minimum compensation an individual would require to voluntarily give up a good or accept a worse outcome.

Willingness to PayConceptWTP, Maximum Price Payable

Willingness to pay (WTP) is the most money a person would give up for a health gain or other benefit, used to value outcomes in cost-benefit analysis.

Willingness-to-Pay EstimationConceptWTP Estimation, WTP Elicitation

The empirical process of measuring willingness to pay, typically through stated preference methods such as contingent valuation or discrete choice experiments.

Willingness-to-Pay ThresholdConceptWTP Threshold, Cost-Effectiveness Willingness-to-Pay

A willingness-to-pay threshold is the cost per QALY below which a treatment counts as good value; strictly, the most society would pay for one extra QALY.

Within Patient AnalysisTerm

A statistical comparison examining changes in outcomes over time within the same individuals, such as their response to two treatments in a crossover trial.

Within Subject VariationConcept

The degree to which repeated measurements on the same individual fluctuate over time, unlike between-subject variation reflecting differences across individuals.

WOMACConceptWestern Ontario and McMaster Universities Osteoarthritis Index

WOMAC is a 24-question index of pain, stiffness and physical function in hip and knee osteoarthritis, used in trials and mapped to EQ-5D utilities.

Work ProductivityTerm

The output an employee generates per unit of time worked, which health conditions can reduce through both absence and diminished performance.

Work Productivity OutcomeTerm

A measure capturing a health condition's effect on work-related productivity, covering both absenteeism, time missed entirely, and presenteeism, reduced performance while present.

Work RVUTerm

A US Medicare relative value component reflecting the physician time, skill, and effort required to perform a specific service.

Workforce PlanningTerm

The process of forecasting future healthcare workforce needs and developing strategies to ensure an adequate supply of trained professionals.

Workforce PolicyTerm

Policy governing the training, distribution, and regulation of the healthcare workforce, covering education funding, licensure, and scope of practice.

Working CapitalTerm

The difference between an organisation's current assets and current liabilities, representing the resources available to fund day-to-day operations.

Working CorrelationTerm

In generalised estimating equations, an assumed correlation structure among repeated observations, improving statistical efficiency even if not perfectly correct.

Worst Case AnalysisTerm

A sensitivity analysis setting every uncertain parameter simultaneously to its least favourable value, producing the most pessimistic possible result the model could generate.

Worst Case ScenarioTerm

A combination of assumptions representing the least favourable plausible circumstances for an intervention's cost-effectiveness, used within scenario analysis.

Written ConsentTerm

A formal process in which a patient's agreement to treatment is documented through their signature on a written consent form.

Wrong Site SurgeryTerm

A serious, generally preventable safety event where a procedure is performed on the wrong body part, patient, or is entirely the wrong procedure.