PubMed Health. A service of the National Library of Medicine, National Institutes of Health.

National Clinical Guideline Centre – Acute and Chronic Conditions (UK). Venous Thromboembolism: Reducing the Risk of Venous Thromboembolism (Deep Vein Thrombosis and Pulmonary Embolism) in Patients Admitted to Hospital. London: Royal College of Physicians (UK); 2010. (NICE Clinical Guidelines, No. 92.)

Glossary of terms

Absolute effect

The difference in the risk of an event between two groups (one subtracted from the other) in a comparative study.

Absolute risk reduction (Risk difference)

See absolute effect

Abstract

Summary of a study, which may be published alone or as an introduction to a full scientific paper.

Acute medical admission

A medical admission concerned with the immediate and early specialist management of adult patients suffering from a wide range of medical conditions who present to, or from within, hospitals, requiring urgent or emergency care

Adherence

The extent to which the patient’s behaviour matches the prescriber’s recommendations. Adherence emphasises the need for agreement and that the patient is free to decide whether or not to adhere to the doctor’s recommendation. 472

Adjustment

A statistical procedure in which the effects of differences in composition of the populations being compared (or treatment given at the same time) have been minimised by statistical methods.

Algorithm (in guidelines)

A flow chart of the clinical decision pathway described in the guideline, where decision points are represented with boxes, linked with arrows.

Allocation concealment

The process used to prevent advance knowledge of group assignment in a RCT. The allocation process should be impervious to any influence by the individual making the allocation, by being administered by someone who is not responsible for recruiting participants.

Anticoagulants

Any agent used to prevent the formation of blood clots. These include oral agents, such as warfarin, and others which are injected into a vein or under the skin, such as heparin.

Anti-embolism stockings

Hosiery which, when worn on the leg, exerts graduated compression on the leg surface and is intended to reduce the incidence of deep vein thrombosis. These should not be confused with “graduated compression stockings” which have a different pressure profile and are not used for the prevention of venous thromboembolism.

Applicability

The degree to which the results of an observation, study or review are likely to hold true in a particular clinical practice setting.

Appraisal of Guidelines, Research and Evaluation (AGREE)

An international collaboration of researchers and policy makers whose aim is to improve the quality and effectiveness of clinical practice guidelines (http://www.agreecollaboration.org). The AGREE instrument, developed by the group, is designed to assess the quality of clinical guidelines.

Arm (of a clinical study)

Sub-section of individuals within a study who receive one particular intervention, for example placebo arm.

Association

Statistical relationship between two or more events, characteristics or other variables. The relationship may or may not be causal.

Audit

See ‘Clinical audit’.

Baseline

The initial set of measurements at the beginning of a study (after run-in period where applicable), with which subsequent results are compared.

Bias

Systematic (as opposed to random) deviation of the results of a study from the ‘true’ results that is caused by the way the study is designed or conducted.

Blinding (masking)

Keeping the study participants, caregivers, researchers and outcome assessors unaware about the interventions to which the participants have been allocated in a study.

Capital costs

Costs of purchasing major capital assets (usually land, buildings or equipment). Capital costs represent investments at one point in time.

Carer (caregiver)

Someone other than a health professional who is involved in caring for a person with a medical condition.

Case-control study

Comparative observational study in which the investigator selects individuals who have experienced an event (For example, developed a disease) and others who have not (controls), and then collects data to determine previous exposure to a possible cause.

Case series

Report of a number of cases of a given disease, usually covering the course of the disease and the response to treatment. There is no comparison (control) group of patients.

Chronic thrombembolic pulmonary hypertension

Abnormally elevated blood pressure within the pulmonary circuit (pulmonary artery).

Clinical audit

A quality improvement process that seeks to improve patient care and outcomes through systematic review of care against explicit criteria and the implementation of change.

Clinical efficacy

The extent to which an intervention is active when studied under controlled research conditions.

Clinical effectiveness

The extent to which an intervention produces an overall health benefit in routine clinical practice.

Clinical impact

The effect that a guideline recommendation is likely to have on the treatment or treatment outcomes, of the target population.

Clinical question

In guideline development, this term refers to the questions about treatment and care that are formulated to guide the development of evidence-based recommendations.

Clinician

A healthcare professional providing direct patient care, for example doctor, nurse or physiotherapist.

Cluster

A closely grouped series of events or cases of a disease or other related health phenomena with well-defined distribution patterns, in relation to time or place or both. Alternatively, a grouped unit for randomisation.

Cochrane Library

A regularly updated electronic collection of evidence-based medicine databases, including the Cochrane Database of Systematic Reviews.

Cochrane Review

A systematic review of the evidence from randomised controlled trials relating to a particular health problem or healthcare intervention, produced by the Cochrane Collaboration. Available electronically as part of the Cochrane Library.

Cohort study

A retrospective or prospective follow-up study. Groups of individuals to be followed up are defined on the basis of presence or absence of exposure to a suspected risk factor or intervention. A cohort study can be comparative, in which case two or more groups are selected on the basis of differences in their exposure to the agent of interest.

Comorbidity

Co-existence of more than one disease or an additional disease (other than that being studied or treated) in an individual.

Comparability

Similarity of the groups in characteristics likely to affect the study results (such as health status or age).

Compliance

The extent to which a person adheres to the health advice agreed with healthcare professionals. May also be referred to as ‘adherence’ or ‘concordance’.

Concordance

This is a recent term whose meaning has changed. It was initially applied to the consultation process in which prescriber and patient agree therapeutic decisions that incorporate their respective views, but now includes patient support in medicine-taking as well as prescribing communication. Concordance reflects social values but does not address medicine-taking and may not lead to improved adherence472

Conference proceedings

Compilation of papers presented at a conference.

Confidence interval (CI)

A range of values for an unknown population parameter with a stated ‘confidence’ (conventionally 95%) that it contains the true value. The interval is calculated from sample data, and generally straddles the sample estimate. The ‘confidence’ value means that if the method used to calculate the interval is repeated many times, then that proportion of intervals will actually contain the true value.

Confounding

In a study, confounding occurs when the effect of an intervention on an outcome is distorted as a result of an association between the population or intervention or outcome and another factor (the ‘confounding variable’) that can influence the outcome independently of the intervention under study.

Consensus methods

Techniques that aim to reach an agreement on a particular issue. Formal consensus methods include Delphi and nominal group techniques, and consensus development conferences. In the development of clinical guidelines, consensus methods may be used where there is a lack of strong research evidence on a particular topic. Expert consensus methods will aim to reach agreement between experts in a particular field.

Control group

A group of patients recruited into a study that receives no treatment, a treatment of known effect, or a placebo (dummy treatment) – in order to provide a comparison for a group receiving an experimental treatment, such as a new drug.

Controlled clinical trial (CCT)

A study testing a specific drug or other treatment involving two (or more) groups of patients with the same disease. One (the experimental group) receives the treatment that is being tested, and the other (the comparison or control group) receives an alternative treatment, a placebo (dummy treatment) or no treatment. The two groups are followed up to compare differences in outcomes to see how effective the experimental treatment was. A CCT where patients are randomly allocated to treatment and comparison groups is called a randomised controlled trial.

Cost benefit analysis

A type of economic evaluation where both costs and benefits of healthcare treatment are measured in the same monetary units. If benefits exceed costs, the evaluation would recommend providing the treatment.

Cost-consequences analysis (CCA)

A type of economic evaluation where various health outcomes are reported in addition to cost for each intervention, but there is no overall measure of health gain.

Cost-effectiveness analysis (CEA)

An economic study design in which consequences of different interventions are measured using a single outcome, usually in ‘natural’ units (For example, life-years gained, deaths avoided, heart attacks avoided, cases detected). Alternative interventions are then compared in terms of cost per unit of effectiveness.

Cost-effectiveness model

An explicit mathematical framework, which is used to represent clinical decision problems and incorporate evidence from a variety of sources in order to estimate the costs and health outcomes.

Cost-utility analysis (CUA)

A form of cost-effectiveness analysis in which the units of effectiveness are quality-adjusted life-years (QALYs).

Continuous passive motion

Where a joint is moved continuously, either by another person bending it or by a machine.

Credible interval

The Bayesian equivalent of a confidence interval.

Decision analysis

A systematic way of reaching decisions, based on evidence from research. This evidence is translated into probabilities, and then into diagrams or decision trees which direct the clinician through a succession of possible scenarios, actions and outcomes.

Decision analytic techniques

A way of reaching decisions, based on evidence from research. This evidence is translated into probabilities, and then into diagrams or decision trees that direct the clinician through a succession of possible scenarios, actions and outcomes.

Decision problem

A clear specification of the interventions, patient populations and outcome measures and perspective adopted in an evaluation, with an explicit justification, relating these to the decision which the analysis is to inform.

Deep-vein thrombosis (DVT)

Venous thrombosis that occurs in the “deep veins” in the legs, thighs, or pelvis.

Discounting

Costs and perhaps benefits incurred today have a higher value than costs and benefits occurring in the future. Discounting health benefits reflects individual preference for benefits to be experienced in the present rather than the future. Discounting costs reflects individual preference for costs to be experienced in the future rather than the present.

Distal

Refers to a part of the body that is farther away from the centre of the body than another part.

Dominance

An intervention is said to be dominated if there is an alternative intervention that is both less costly and more effective.

Dosage

The prescribed amount of a drug to be taken, including the size and timing of the doses.

Double blind/masked study

A study in which neither the subject (patient) nor the observer (investigator/clinician) is aware of which treatment nor intervention the subject is receiving. The purpose of blinding is to protect against bias.

DVT

See ‘Deep-vein thrombosis’.

Drop-out

A participant who withdraws from a clinical trial before the end.

Economic evaluation

Comparative analysis of alternative health strategies (interventions or programmes) in terms of both their costs and consequences.

Effect (as in effect measure, treatment effect, estimate of effect, effect size)

The observed association between interventions and outcomes or a statistic to summarise the strength of the observed association.

Effectiveness

See ‘Clinical effectiveness’.

Efficacy

See ‘Clinical efficacy’.

Elective

Name for clinical procedures that are regarded as advantageous to the patient but not urgent.

Electrical stimulation

Designed to increase venous blood flow velocity out of the leg to reduce the incidence of post-surgical venous thrombosis.

Emergency admission

When admission is unpredictable and at short notice because of clinical need.

Epidemiological study

The study of a disease within a population, defining its incidence and prevalence and examining the roles of external influences (For example, infection, diet) and interventions.

Equity

Fair distribution of resources or benefits.

Evidence

Information on which a decision or guidance is based. Evidence is obtained from a range of sources including randomised controlled trials, observational studies, expert opinion (of clinical professionals and/or patients).

Evidence table

A table summarising the results of a collection of studies which, taken together, represent the evidence supporting a particular recommendation or series of recommendations in a guideline.

Exclusion criteria (literature review)

Explicit standards used to decide which studies should be excluded from consideration as potential sources of evidence.

Exclusion criteria (clinical study)

Criteria that define who is not eligible to participate in a clinical study.

Expert consensus

See ‘Consensus methods’.

Extended dominance

If Option A is both more clinically effective than Option B and has a lower cost per unit of effect, when both are compared with a do-nothing alternative then Option A is said to have extended dominance over Option B. Option A is therefore more efficient and should be preferred, other things remaining equal.

Extrapolation

In data analysis, predicting the value of a parameter outside the range of observed values.

Follow up

Observation over a period of time of an individual, group or initially defined population whose appropriate characteristics have been assessed in order to observe changes in health status or health-related variables.

Foot impulse devices(FID)

The foot impulse device is designed to stimulate the leg veins (venous pump) artificially by compressing the venous plexus and mimicking normal walking and reducing stasis in immobilised patients.

Generalisability

The extent to which the results of a study based on measurement in a particular patient population and/or a specific context hold true for another population and/or in a different context. In this instance, this is the degree to which the guideline recommendation is applicable across both geographical and contextual settings. For instance, guidelines that suggest substituting one form of labour for another should acknowledge that these costs might vary across the country.

Gold standard

See ‘Reference standard’.

Goodness-of-fit

How well a statistical model or distribution compares with the observed data.

Graduated compression stockings (GCS)

Stockings manufactured to provide compression around legs at gradually increasing pressures. There are two different standards for graduated compression stockings, the British Standard and the European Standard. These are different to anti-embolism stockings which are used for the prevention of venous thromboembolism.

Grey literature

Reports that are unpublished or have limited distribution, and are not included in the common bibliographic retrieval systems.

Harms

Adverse effects of an intervention.

Health economics

The study of the allocation of scarce resources among alternative healthcare treatments. Health economists are concerned with both increasing the average level of health in the population and improving the distribution of health.

Health-related quality of life (HRQL)

A combination of an individual’s physical, mental and social well-being; not merely the absence of disease.

Heparin-induced thrombocytopenia (HIT)

Low blood platelet count resulting from the administration of heparin (or heparin-like agents). Despite having a low platelet count, patients with this condition are at high risk of their blood clotting.

Heterogeneity

Or lack of homogeneity. The term is used in meta-analyses and systematic reviews when the results or estimates of effects of treatment from separate studies seem to be very different – in terms of the size of treatment effects or even to the extent that some indicate beneficial and others suggest adverse treatment effects. Such results may occur as a result of differences between studies in terms of the patient populations, outcome measures, definition of variables or duration of follow-up.

HIT

See ‘Heparin-induced thrombocytopenia’.

Homogeneity

This means that the results of studies included in a systematic review or meta-analysis are similar and there is no evidence of heterogeneity. Results are usually regarded as homogeneous when differences between studies could reasonably be expected to occur by chance.

Hypothesis

A supposition made as a starting point for further investigation.

Inclusion criteria (literature review)

Explicit criteria used to decide which studies should be considered as potential sources of evidence.

Incremental analysis

The analysis of additional costs and additional clinical outcomes with different interventions.

Incremental cost

The mean cost per patient associated with an intervention minus the mean cost per patient associated with a comparator intervention

Incremental cost effectiveness ratio (ICER)

The difference in the mean costs in the population of interest divided by the differences in the mean outcomes in the population of interest.

Incremental net benefit (INB)

The value (usually in monetary terms) of an intervention net of its cost compared with a comparator intervention. The INB can be calculated for a given cost-effectiveness (willingness to pay) threshold. If the threshold is £20,000 per QALY gained then the INB is calculated as: (£20,000 × QALYs gained) – Incremental cost.

Index

In epidemiology and related sciences, this word usually means a rating scale, for example, a set of numbers derived from a series of observations of specified variables. Examples include the various health status indices, and scoring systems for severity or stage of cancer.

Indication (specific)

The defined use of a technology as licensed by the Medicines and Healthcare products Regulatory Agency (MHRA).

Intention-to-treat analysis (ITT analysis)

An analysis of the results of a clinical study in which the data are analysed for all study participants as if they had remained in the group to which they were randomised, regardless of whether or not they remained in the study until the end, crossed over to another treatment or received an alternative intervention.

Intermediate outcomes

Outcomes that are related to the outcome of interest but may be more easily assessed within the context of a clinical study: for example, blood pressure reduction is related to the risk of a stroke.

Intermittent pneumatic compression devices (IPCD)

A method of prophylaxis that comprises the use of inflatable garments wrapped around the legs, inflated by a pneumatic pump. The pump provides intermittent cycles of compressed air which alternately inflates and deflates the chamber garments, enhancing venous return.

Internal validity

The degree to which the results of a study are likely to approximate the ‘truth’ for the participants recruited in a study (that is, are the results free of bias?). It refers to the integrity of the design and is a prerequisite for applicability (external validity) of a study’s findings. See ‘External validity’.

Intervention

Healthcare action intended to benefit the patient, for example, drug treatment, surgical procedure, psychological therapy.

Intraoperative

The period of time during a surgical procedure.

Length of stay (LOS)

The total number of days a participant stays in hospital.

Licence

See ‘Product licence’.

Life year (LY)

A measure of health outcome which shows the number of years of remaining life expectancy.

Life-years gained

Average years of life gained per person as a result of the intervention.

Mechanical

Physical (as opposed to chemical) agent used, in this context, to reduce likelihood of thrombosis. Mechanical methods of DVT prophylaxis work to combat venous stasis and include: anti-embolism stockings/Graduated compression stockings (GCS), intermittent pneumatic compression devices (IPCD), foot impulse devices, also known as foot pumps (FID)

Medical devices

All products, except medicines, used in healthcare for the diagnosis, prevention, monitoring or treatment of illness or handicap.

Medicines and Healthcare Products Regulatory Agency (MHRA)

The Executive Agency of the Department of Health protecting and promoting public health and patient safety by ensuring that medicines, healthcare products and medical equipment meet appropriate standards of safety, quality, performance and effectiveness, and are used safely.

Meta-analysis

A statistical technique for combining (pooling) the results of a number of studies that address the same question and report on the same outcomes to produce a summary result. The aim is to derive more precise and clear information from a large data pool. It is generally more reliably likely to confirm or refute a hypothesis than the individual trials.

Multivariate model

A statistical model for analysis of the relationship between two or more predictor (independent) variables and the outcome (dependent) variable.

Narrative summary

Summary of findings given as a written description.

Network Meta-analysis (NMA)

Statistical technique for combining all direct and indirect evidence into one analysis (see Section 3.10 for details on methods)

Number needed to treat (NNT)

The number of patients that who on average must be treated to prevent a single occurrence of the outcome of interest.

Observational study

Retrospective or prospective study in which the investigator observes the natural course of events with or without control groups; for example, cohort studies and case–control studies.

Odds ratio (OR)

A measure of treatment effectiveness. The odds of an event happening in the treatment group, expressed as a proportion of the odds of it happening in the control group. The ‘odds’ is the ratio of events to non-events.

Off-label

A drug or device used treat a condition or disease for which it is not specifically licensed.

Older people

People over the age of 65 years.

Operating costs

Ongoing costs of carrying out an intervention, excluding capital costs.

Opportunity cost

The opportunity cost of investing in a healthcare intervention is the loss of other healthcare programmes that are displaced by its introduction. This may be best measured by the health benefits that could have been achieved had the money been spent on the next best alternative healthcare intervention.

Outcome

Measure of the possible results that may stem from exposure to a preventive or therapeutic intervention. Outcome measures may be intermediate endpoints or they can be final endpoints. See ‘Intermediate outcome’.

P values

The probability that an observed difference could have occurred by chance, assuming that there is in fact no underlying difference between the means of the observations. If the probability is less than 1 in 20, the P value is less than 0.05; a result with a P value of less than 0.05 is conventionally considered to be ‘statistically significant’.

PE

See ‘Pulmonary embolism’.

Peer review

A process where research is scrutinised by experts that have not been involved in the design or execution of the studies.

Perioperative

The period from admission through surgery until discharge, encompassing pre-operative and post-operative periods.

Placebo

An inactive and physically identical medication or procedure used as a comparator in controlled clinical trials.

Placebo effect

A beneficial (or adverse) effect produced by a placebo and not due to any property of the placebo itself.

Post-thrombotic (Post-phlebitic) Syndrome

Chronic pain, swelling, and occasional ulceration of the skin of the leg that occur as a consequence of previous venous thrombosis.

Postoperative

Pertaining to the period after patients leave the operating theatre, following surgery.

Preoperative

Pertaining to the period before surgery commences.

Primary care

Healthcare delivered to patients outside hospitals. Primary care covers a range of services provided by GPs, nurses and other healthcare professionals, dentists, pharmacists and opticians.

Primary research

Study generating original data rather than analysing data from existing studies (which is called secondary research).

Product licence

An authorisation from the MHRA to market a medicinal product.

Prognosis

A probable course or outcome of a disease. Prognostic factors are patient or disease characteristics that influence the course. Good prognosis is associated with low rate of undesirable outcomes; poor prognosis is associated with a high rate of undesirable outcomes.

Prophylaxis

A measure taken for the prevention of a disease.

Prospective study

A study in which people are entered into the research and then followed up over a period of time with future events recorded as they happen. This contrasts with studies that are retrospective.

Proximal

Refers to a part of the body that is closer to the centre of the body than another part.

Pulmonary embolism (PE)

A blood clot that breaks off from the deep veins and travels round the circulation to block the pulmonary arteries (arteries in the lung). Most deaths arising from DVT are caused by PE.

Pulmonary hypertension

See ‘Chronic thromboembolic pulmonary hypertension’.

Qualitative research

Research concerned with subjective outcomes relating to social, emotional and experiential phenomena in health and social care.

Quality of life

See ‘Health-related quality of life’.

Quality-adjusted life-year (QALY)

An index of survival that is adjusted to account for the patient’s quality of life during this time. QALYs have the advantage of incorporating changes in both quantity (longevity/mortality) and quality (morbidity, psychological, functional, social and other factors) of life. Used to measure benefits in cost-utility analysis. The QALYs gained are the mean QALYs associated with one treatment minus the mean QALYs associated with an alternative treatment.

Quantitative research

Research that generates numerical data or data that can be converted into numbers, for example clinical trials or the national Census which counts people and households.

Quick Reference Guide

An abridged version of NICE guidance, which presents the key priorities for implementation and summarises the recommendations for the core clinical audience.

Randomisation

Allocation of participants in a research study to two or more alternative groups using a chance procedure, such as computer-generated random numbers. This approach is used in an attempt to ensure there is an even distribution of participants with different characteristics between groups and thus reduce sources of bias.

Randomised controlled trial (RCT)

A comparative study in which participants are randomly allocated to intervention and control groups and followed up to examine differences in outcomes between the groups.

RCT

See ‘Randomised controlled trial’.

Relative risk (RR)

The number of times more likely or less likely an event is to happen in one group compared with another (calculated as the risk of the event in group A/the risk of the event in group B).

Remit

The brief given by the Department of Health and Welsh Assembly Government at the beginning of the guideline development process. This defines core areas of care that the guideline needs to address.

Resource implication

The likely impact in terms of finance, workforce or other NHS resources.

Retrospective study

A retrospective study deals with the present/past and does not involve studying future events. This contrasts with studies that are prospective.

Review of the literature

An article that summarises the evidence contained in a number of different individual studies and draws conclusions about their findings. It may or may not be systematically researched and developed.

Secondary benefits

Benefits resulting from a treatment in addition to the primary, intended outcome.

Selection bias (also allocation bias)

A systematic bias in selecting participants for study groups, so that the groups have differences in prognosis and/or therapeutic sensitivities at baseline. Randomisation (with concealed allocation) of patients protects against this bias.

Selection criteria

Explicit standards used by guideline development groups to decide which studies should be included and excluded from consideration as potential sources of evidence.

Sensitivity (of a search)

The proportion of relevant studies identified by a search strategy expressed as a percentage of all relevant studies on a given topic. It describes the comprehensiveness of a search method (that is, its ability to identify all relevant studies on a given topic). Highly sensitive strategies tend to have low levels of specificity and vice versa.

Sensitivity analysis

A means of representing uncertainty in the results of economic evaluations. Uncertainty may arise from missing data, imprecise estimates or methodological controversy. Sensitivity analysis also allows for exploring the generalisability of results to other settings. The analysis is repeated using different assumptions to examine the effect on the results.

One-way simple sensitivity analysis (univariate analysis): each parameter is varied individually in order to isolate the consequences of each parameter on the results of the study.

Multi-way simple sensitivity analysis (scenario analysis): two or more parameters are varied at the same time and the overall effect on the results is evaluated.

Threshold sensitivity analysis: the critical value of parameters above or below which the conclusions of the study will change are identified.

Probabilistic sensitivity analysis: probability distributions are assigned to the uncertain parameters and are incorporated into evaluation models based on decision analytical techniques (For example, Monte Carlo simulation).

Significantly Reduced Mobility

Defined by the GDG as:

‘patients who are bed bound, unable to walk unaided or likely to spend a substantial proportion of their day in bed or in a chair’

Stakeholder

Those with an interest in the use of a technology under appraisal or a guideline under development. Stakeholders include manufacturers, sponsors, healthcare professionals, and patient and carer groups.

Statistical power

The ability to demonstrate an association when one exists. Power is related to sample size; the larger the sample size, the greater the power and the lower the risk that a possible association could be missed.

Synthesis of evidence

A generic term to describe methods used for summarising (comparing and contrasting) evidence into a clinically meaningful conclusion in order to answer a defined clinical question. This can include systematic review (with or without meta-analysis), qualitative and narrative summaries.

Systematic review

Research that summarises the evidence on a clearly formulated question according to a pre-defined protocol using systematic and explicit methods to identify, select and appraise relevant studies, and to extract, collate and report their findings. It may or may not use statistical meta-analysis.

Thrombophilia

The genetic or acquired prothrombotic states that increase the tendency to venous thromboembolism. It is a condition which leads to a tendency for a person’s blood to clot inappropriately.

Thromboprophylaxis

A measure taken to reduce the risk of thrombosis.

Time horizon

The time span used in the NICE appraisal which reflects the period over which the main differences between interventions in health effects and use of healthcare resources are expected to be experienced, and taking into account the limitations of supportive evidence.

Treatment allocation

Assigning a participant to a particular arm of the trial.

Treatment options

The choices of intervention available.

Utility

A measure of the strength of an individual’s preference for a specific health state in relation to alternative health states. The utility scale assigns numerical values on a scale from 0 (death) to 1 (optimal or ‘perfect’ health). Health states can be considered worse than death and thus have a negative value.

Venous thromboembolism (VTE)

The blocking of a blood vessel by a blood clot dislodged from its site of origin. It includes both DVT and PE.

Venous thrombosis (VT)

A condition in which a blood clot (thrombus) forms in a vein.

Copyright © 2010, National Clinical Guideline Centre - Acute and Chronic Conditions.

Apart from any fair dealing for the purposes of research or private study, criticism or review, as permitted under the Copyright, Designs and Patents Act, 1988, no part of this publication may be reproduced, stored or transmitted in any form or by any means, without the prior written permission of the publisher or, in the case of reprographic reproduction, in accordance with the terms of licences issued by the Copyright Licensing Agency in the UK. Enquiries concerning reproduction outside the terms stated here should be sent to the publisher at the UK address printed on this page.

The use of registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant laws and regulations and therefore for general use.

The rights of National Clinical Guideline Centre - Acute and Chronic Conditions to be identified as Author of this work have been asserted by them in accordance with the Copyright, Designs and Patents Act, 1988.

Cover of Venous Thromboembolism
Venous Thromboembolism: Reducing the Risk of Venous Thromboembolism (Deep Vein Thrombosis and Pulmonary Embolism) in Patients Admitted to Hospital.
NICE Clinical Guidelines, No. 92.
National Clinical Guideline Centre – Acute and Chronic Conditions (UK).

Download

NICE (National Institute for Health and Care Excellence)

PubMed Health Blog...

read all...

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...