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Icelandic Medicines Agency

Identified risk

An adverse event for which there is adequate evidence of an association with the use of the medicinal product of interest.

Idiosyncratic drug reaction

A reaction that occurs rarely and unpredictably in a small percentage of the population in response to a treatment or medicine. These reactions frequently occur with exposure to new medicines and cannot be explained by the known mechanisms of action of the medicine, do not occur at any dose in most patients, and develop mostly unpredictably in susceptible individuals only. Based on the underlying mechanisms, idiosyncratic reactions can be differentiated into (1) immune-mediated hypersensitivity reactions such as skin rashes to serious systemic symptoms (2) reactions involving non-immune individual susceptibility, often related to abnormal production or detoxification of cytotoxic metabolites


The ability of a substance to produce an immune response.


Immunotoxicity is harm occurring to the immune system caused by exposure to chemical substances. Testing for immunotoxicity is a standard part of developing substances as potential new medicines. Symptoms of immunotoxicity can include increased rates or severity of infectious diseases or cancer. Toxic agents can also cause autoimmune diseases, in which healthy tissue is attacked by the body™s own immune system. Allergy is another form of immunotoxicity, and many chemicals are known to induce allergic reactions in some people.

Impartial Witness

The role of an impartial witness is to attend the informed consent process if the patient/participant or their legally authorised representative (LAR) cannot read. The impartial witness reads the relevant documentation supplied to the participant (for instance, the consent form). The witness must be independent of the research and may not be unfairly influenced by those involved in the trial. They may, for example, be a non-research member of staff or the patient's relative.

Inactivated vaccine

Inactivated vaccines use the killed version of the pathogen that causes a disease.


The number of new cases of a health event (such as development of a disease, or reaction to a medicine) that occur during a specific time period, usually a year, in a specified population. Incidence is therefore also a measure of the risk of experiencing the health event during a certain period of time.

Inclusion Criteria

Inclusion criteria are the characteristics that potential participants must have in order to be considered for participation in a trial. They describe the patient population and patient selection criteria.

Inclusion criteria should specify the type of testing used to make the patients' diagnosis, as well as specific disease requirements (for example, how severe the disease is, failure or success with previous treatments, plus any other factors that might affect prognosis such as age, sex, or ethnicity).

The inclusion criteria (and exclusion criteria) are important parts of a trial protocol. If they are properly defined, inclusion and exclusion criteria will increase the chances that the trial produces reliable results. They also protect participants from harm and minimise the risks.

Independent Ethics Committee

Independent Ethics Committee


In medicine, indication refers to a health condition (therapeutic area) for which a specific intervention (medicinal product, medical device, treatment, procedure) is developed to cure, relieve symptoms, prevent or diagnose. The indication, as specified in the ˜Summary of Product Characteristics™ (SmPC) document, determines the boundaries of lawful use of such medicinal product.

Informed Consent

Informed consent is a person's voluntary agreement, based on an understanding of the relevant information, to participate in research or a clinical trial, or to undergo a particular medical intervention.

Before any research may be carried out, participants must be informed about all aspects of the study and/or intervention, including the aims, methods, anticipated benefits, and potential risks. Participants must also be made aware that they can withdraw from the research at any stage without any negative consequences to their ongoing care or treatment. This information must be given in an accessible and understandable way (for instance via a participant information sheet), and individuals should be given the opportunity to ask questions about the research.

Informed consent is usually documented in writing with a signed and dated consent form. However, informed consent should be an ongoing process throughout a study, and researchers should ensure that participants are made aware of any new information which might influence their decision about whether to take part or not.

In rare circumstances (for example, when an individual may not be able to give informed consent), the usual practices for informed consent may not be possible. Researchers may obtain delayed consent (for instance, for research into emergency situations) or consent by proxy (when the ability to consent is delegated to someone else). In some cases informed consent may be implied by a person™s actions or inaction or silence.

Innovative characteristics

In medicinal products, this may be defined as offering additional clinical efficacy or effectiveness as compared to the current best standard of care. Improvement to the use of a medicine in addition to an added clinical benefit (such as convenience to patients of, for example, a different mode of delivery, or other characteristics that may improve adherence to therapy, with resulting improvements in clinical outcomes and/or quality of life) may also be considered innovative characteristics.

Innovative Medicines Initiative

Innovative Medicines Initiative (IMI)"

Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen

Institutional Review Board

Institutional Review Board

Integrated Research Application System

Integrated Research Application System


Intention-to-treat (ITT) is an analysis of the participants taking part in a clinical trial, based on the group to which they were initially assigned, and not on the treatment eventually received. It does not matter if they drop out, whether they fully adhere to the treatment, or even if they switch to an alternative treatment.

Intention-to-treat analyses are often used to assess the effectiveness of a new treatment because they are seen to reflect real life: not everyone adheres to the treatment they are given, and doctors often change treatments depending on how their patient's condition changes.

Interim analysis

In clinical trials and other scientific studies, an interim analysis is an analysis of the current data from an ongoing trial, in which the primary research question is addressed. It has the potential to modify the conduct of the study. Depending on the results, an interim analysis may lead to changes, such as stopping one treatment arm or changing the number of participants in a group, or stopping the trial altogether.

An example of an interim analysis leading to the early stopping of a study comes from a trial to better identify patients with coronary heart disease who would benefit from an implantable device. The trial compared the devices to treatment with medicines in patients who had survived life-threatening coronary events. The trial was stopped when interim analysis showed a significant reduction in all causes of death in patients assigned to treatment with the implantable device.

An interim analysis requires careful advanced planning and appropriate adjustments to the statistical approach. An interim analysis and any anticipated changes to the trial must be described and justified in the study protocol. The option to modify the design of an ongoing clinical trial is becoming increasingly common and is known as adaptive design.

Intermediate endpoint

In clinical trials, intermediate endpoints are measures that may be associated with disease status or progression toward a primary endpoint (such as mortality or morbidity). It may be a measure of a body function or disease symptoms (e.g. measures of lung function in chronic obstructive pulmonary disease (COPD)) that is expected to correlate with changes observed on primary endpoints. Clinical trials are often designed to measure changes of an intermediate endpoint and evaluate the effects of an intervention on clinical outcomes.

Internal Validity

Internal validity in a clinical trial is the ability of the trial to reach the correct conclusion about whether or not, and to what extent, a treatment is causing a measured effect on the participants. It implies accurate and unbiased measurement of that effect.

Internal validity is achieved when possible alternative explanations for the measured effect can be excluded, such as chance or bias. Well-designed clinical trials take this into account, for example by using randomisation and blinding.

International Council for Harmonisation

Formerly the International Conference on Harmonisation. The International Council on Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) produces harmonised guidelines for global pharmaceutical development, and their regulation. It brings together the regulatory authorities and the pharmaceutical industry from five regions (Europe, Japan, USA, Canada and Switzerland).

ICH has been established in order to reduce the duplication of clinical trials and create a more streamlined regulatory assessment process for new applications. As such, ICH has developed four sets of guidelines provided for specific topics including quality, safety, efficacy and multidisciplinary (e.g. ICH medical terminology (MedDRA), or the Common Technical Document (CTD)) which are implemented by the regulatory authorities of its membership.

International Federation of Pharmaceutical Manufacturers and Associations

International Federation of Pharmaceutical Manufacturers and Associations

International Network of Agencies for Health Technology Assessment

International Network of Agencies for Health Technology Assessment"

International Non-proprietary Name

An International Non-proprietary Name (INN) is an official generic name given to a pharmaceutical compound. INNs facilitate communication by providing a standard name for each substance in the market with more than one brand name. Each INN is a unique name that is globally recognised and is public property. A Non-proprietary Name is also known as a generic name. Examples of INNs are: ibuprofen, mefloquine, and diazepam.

International Society for Pharmacoeconomics and Outcomes Research

International Society for Pharmacoeconomics and Outcomes Research"


In medicine, intervention is an action which changes the outcome or course of a condition or disease so as to prevent harm or improve health through the use of treatments, medicinal products, medical devices or procedures/surgery.

Interventional Study

An interventional study is one in which the participants receive some kind of intervention, such as a new medicine, in order to evaluate it. In the medicines development process, medicines are evaluated through interventional studies known as clinical trials.

There are many variations in how clinical trials are designed, but they are commonly randomised (participants are allocated to different arms in the study randomly) and controlled (the study medicine is given to one arm, and the outcomes are compared with an alternative treatment or placebo given to another arm). These are called randomised controlled trials, or RCTs.


Intravenous means ˜within the vein™. It is the infusion of liquid directly into a vein using a syringe or intravenous catheter (tube).

Compared with other routes of administration, the intravenous route is the fastest way to deliver fluids and medicines into the blood stream (the systemic circulation). In intravenous therapy, the bioavailability of the medication is 100%.

Investigational Medicinal Product

An investigational medicinal product is an active ingredient or placebo that has been pharmaceutically formulated (prepared) for human use which is being tested, or used as a comparator, in a clinical trial.

Typically IMPs have not yet received marketing authorisation, however in some circumstances they may be products that have been authorised:

  • when they have been made using a different formulation than that which is authorised (e.g. different dose),
  • when the authorised product is to be used as the test substance or comparator in a clinical trial,
  • when used for an unapproved indication (off-label), or
  • when used to gain further information about an approved use.

Investigational Medicinal Product Dossier

The Investigational Medicinal Product Dossier (IMPD) is an evolving document containing currently available information about an investigational medicinal product (IMP). It includes summaries of information related to the quality, manufacture and control of any IMP (including reference product and/or placebo), data from non-clinical studies and from its clinical use, and the product™s phase of development.

Investigational plan

An investigational plan is a medicines development plan to support the authorisation of a medicine for humans. It aims to ensure that the necessary data is obtained through clinical and other studies.


A clinical trial investigator is responsible for the conduct of the trial at a trial site. If a trial is conducted by a team of individuals at a trial site, the investigator is the leader responsible for the team, and is called the principle investigator.

Investigator's Brochure

The Investigator's Brochure (IB) is a comprehensive document that summarises all the relevant clinical and non-clinical information about the medicine being studied in humans.

An IB contains a 'Summary of Data and Guidance for the Investigator' section, the aim of which is 'to provide the investigator with a clear understanding of the possible risks and adverse reactions, and of the specific tests, observations, and precautions that may be needed for a clinical trial.'

The IB also provides information to help with the clinical management of participants taking part in the clinical trial.

The sponsor (the organisation running and overseeing the trial) is responsible for keeping the information in the IB up-to-date. The IB is of critical importance. It should be reviewed annually and must be updated when any new and important information becomes available, such as when a medicine has received marketing approval and can be prescribed for use commercially.

Owing to the importance of the IB for the safety of participants in clinical trials, the International Conference on Harmonisation (ICH) has prepared a detailed guidance document for the authoring of the IB in the European Union, Japan, and the United States.

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