• Sample Size

    The number of participants in the trial. The intended sample size is the number of participants planned to be included in the trial, usually determined using a statistical power calculation. The sample size should be adequate to provide a high probability of detecting as significant an effect size of a given magnitude if such an effect actually exists.

    The achieved sample size is the number of participants enrolled, treated or analysed in the study.

  • Self-Evident Corrections

    A list of corrections to the case report form that can be made by the sponsor’s data management staff without the requirement for case-by-case referral to the investigator.  For example, if a case report form page lists concomitant medications taken by a patient but the box stating ‘Are there any medications this cycle?’ is blank, the box may be ticked by the data manager. 

    A list of such data correction conventions should be agreed by the investigator prior to data management activities taking place.

  • Serious Adverse Event (SAE) or Serious Adverse Reaction (SAR)

    Any adverse event or adverse reaction that results in death, is life-threatening*, requires hospitalisation or prolongation of existing hospitalisation, results in persistent or significant disability or incapacity, or is a congenital anomaly or birth defect.

    Comment:  Medical judgement should be exercised in deciding whether an adverse event/reaction should be classified as serious in other situations. Important adverse events/reactions that are not immediately life-threatening or do not result in death or hospitalisation, but may jeopardise the subject or may require intervention to prevent one of the other outcomes listed in the definition above, should also be considered serious.

    * Life-threatening in the definition of a serious adverse event or serious adverse reaction refers to an event in which the subject was at risk of death at the time of the event. It does not refer to an event which hypothetically might have caused death if it were more severe.

  • Serious Breach of GCP or Protocol

    A “serious breach” is a breach which is likely to effect to a significant degree:

    a) the safety or physical or mental integrity of the subjects of the trial; or

    b) the scientific value of the trial.

  • Service Level Agreement (SLA)

    A communication document that makes clear what the supplier will deliver and what the organisation will ensure. It is based on the conditions of contract and specification and does not in any way replace them.

  • Source Data

    All information in original records and certified copies of original records of clinical findings, observations, or other activities in a clinical trial necessary for the reconstruction and evaluation of the trial. Source data are contained in source documents (original records or certified copies). Source data may be in hard copy or electronic format.

    See Reflection paper on expectations for electronic source data and data transcribed to electronic data collection tools in clinical trials (PDF, 127 KB).

  • Source Documents

    Original documents, data, and records (e.g., hospital records, clinical and office charts, laboratory notes, memoranda, subjects' diaries or evaluation checklists, pharmacy dispensing records, recorded data from automated instruments, copies or transcriptions certified after verification as being accurate copies, microfiches,  photographic negatives, microfilm or magnetic media, x-rays, subject files, and records kept at the pharmacy, at the laboratories and at medico-technical departments involved in the clinical trial).

  • Sponsor

    The individual, or organisation (or group of individuals or organisations) that takes on responsibility for confirming that there are proper arrangements in place to initiate, manage and monitor, and finance a study. Responsibilities are defined by the UK Policy Framework for Health and Social Care Research and by the Clinical Trials Regulations.

    Where the term sponsor is used in this Toolkit, it refers to the individual, organisation or group member delegated sponsor responsibilities/functions.

  • Standard Operating Procedure (SOPs)

    Written instructions to achieve uniformity of the performance of a specific function.

  • Statistical Analysis Plan

    A statistical analysis plan is a document that contains a more technical and detailed elaboration of the principal features of the analysis described in the protocol, and includes detailed procedures for executing the statistical analysis of the primary and secondary variables and other data.

  • Subject

    An individual who participates in a clinical trial as either a recipient of the investigational medicinal product or a control. The preferred term for the HRA, NRES and many key trials stakeholders is 'Participant' but the term 'Subject' is referenced in law for CTIMPs. See also Participant.

  • Substantial Amendment

    A change to the terms of the approval given by either:

    • the competent authority (MHRA in the UK) or the research ethics committee or;
    • a change to the protocol or any other document submitted with the applications,

    which significantly affects one of the following:

    • the safety or physical or mental integrity of study participants
    • the conduct or management of the study
    • the scientific value of the study
    • the quality or safety of any investigational medicinal product used in the study.
  • Summary of Product Characteristics (SmPC or SPC)

    The basis of information for health professionals on how to use the medicinal product safely and effectively. They are written and updated by pharmaceutical companies and are based on their research and product knowledge. It is then checked and approved by the UK or European medicines licensing agency.

    The leaflet that is included in the pack with a medicine is a patient-friendly version of this document.

  • Suspected Unexpected Serious Adverse Reactions (SUSAR)

    An adverse reaction that is both unexpected (not consistent with the applicable product information) and also meets the definition of a Serious Adverse Event/Reaction.

    View an Adverse Event flowchart (pdf, 180.98 KB) outlining the assessments required to determine whether a SUSAR has occurred.